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GEOCHEMISTRY ARTICLES – August 2018

Analytical Chemistry

Amiri, A., Baghayeri, M., Sedighi, M., 2018. Magnetic solid-phase extraction of polycyclic aromatic hydrocarbons using a graphene oxide/Fe3O4@polystyrene nanocomposite. Microchimica Acta 185, 393.

Dendisová, M., Jeništová, A., Parchaňská-Kokaislová, A., Matějka, P., Prokopec, V., Švecová, M., 2018. The use of infrared spectroscopic techniques to characterize nanomaterials and nanostructures: A review. Analytica Chimica Acta 1031, 1-14.

Li, Y., Zhang, L., Wu, L., Sun, S., Shan, H., Wang, Z., 2018. Purification and enrichment of polycyclic aromatic hydrocarbons in environmental water samples by column clean-up coupled with continuous flow single drop microextraction. Journal of Chromatography A 1567, 81-89.

Qin, S.-B., Fan, Y.-H., Mou, X.-X., Li, X.-S., Qi, S.-H., 2018. Preparation of phenyl-modified magnetic silica as a selective magnetic solid-phase extraction adsorbent for polycyclic aromatic hydrocarbons in soils. Journal of Chromatography A 1568, 29-37.

Vasilenko, P.A., Kornienko, S.G., Primerova, O.V., 2018. IR spectrometric determination of weight fractions of oil and gas condensate in products oil and gas condensate wells. Journal of Analytical Chemistry 73, 777-785.

Yuan, Y., Cai, X., Tan, B., Zhou, S., Xing, B., 2018. Molecular insights into reversible redox sites in solid-phase humic substances as examined by electrochemical in situ FTIR and two-dimensional correlation spectroscopy. Chemical Geology 494, 136-143.

GAS CHROMATOGRAPHY/GC×GC/GC-MS

Alexandrino, G.L., Augusto, F., 2018. Comprehensive two-dimensional gas chromatography–mass spectrometry/selected ion monitoring (GC×GC–MS/SIM) and chemometrics to enhance inter-reservoir geochemical features of crude oils. Energy & Fuels 32, 8017-8023.

Cai, H., Stearns, S.D., 2018. A comprehensive two-dimensional gas chromatography valve modulation method using hold-release primary column flow for long secondary separation time with 100% transfer. Journal of Chromatography A 1569, 200-211.

Cui, C., Zhang, L., Ma, Y., Billa, T., Hou, Z., Shi, Q., Zhao, S., Xu, C., Klein, M.T., 2018. Computer-aided gasoline compositional model development based on GC-FID analysis. Energy & Fuels 32, 8366-8373.

França, D., Pereira, V.B., Coutinho, D.M., Ainstein, L.M., Azevedo, D.A., 2018. Speciation and quantification of high molecular weight paraffins in Brazilian whole crude oils using high-temperature comprehensive two-dimensional gas chromatography. Fuel 234, 1154-1164.

Gómez-Ramos, M.M., Ucles, S., Ferrer, C., Fernández-Alba, A.R., Hernando, M.D., 2019. Exploration of environmental contaminants in honeybees using GC-TOF-MS and GC-Orbitrap-MS. Science of The Total Environment 647, 232-244.

Jennerwein, M., Eschner, M., Wilharm, T., Gröger, T., Zimmermann, R., 2019. Evaluation of reversed phase versus normal phase column combination for the quantitative analysis of common commercial available middle distillates using GC × GC-TOFMS and Visual Basic Script. Fuel 235, 336-338.

Keshet, U., Goldshlag, P., Amirav, A., 2018. Pesticide analysis by pulsed flow modulation GCxGC-MS with Cold EI—an alternative to GC-MS-MS. Analytical and Bioanalytical Chemistry 410, 5507-5519.

Li, H., Liu, G., Zhang, X., 2018. Analysis of kerosene-based endothermic hydrocarbon fuel using comprehensive two-dimensional gas chromatography coupled to mass spectrometry. Chinese Journal of Chromatography 36, 780-785.

Luo, F., Feng, F., Zhao, B., Tian, B., Yang, X., Zhou, H., Li, X., 2018. Research progress of micro-electro-mechanical systems micro gas chromatography columns. Chinese Journal of Chromatography 36, 707-715.

Martins, C., Brandão, T., Almeida, A., Rocha, S.M., 2018. Unveiling the lager beer volatile terpenic compounds. Food Research International 114, 199-207.

Mazur, D.M., Zenkevich, I.G., Artaev, V.B., Polyakova, O.V., Lebedev, A.T., 2018. Regression algorithm for calculating second-dimension retention indices in comprehensive two-dimensional gas chromatography. Journal of Chromatography A 1569, 178-185.

Muscalu, A.M., Górecki, T., 2018. Comprehensive two-dimensional gas chromatography in environmental analysis. TrAC Trends in Analytical Chemistry 106, 225-245.

Narduzzi, L., Franciosi, E., Carlin, S., Tuohy, K., Beretta, A., Pedrotti, F., Mattivi, F., 2018. Applying novel approaches for GC × GC-TOF-MS data cleaning and trends clustering in VOCs time-series analysis: Following the volatiles fate in grass baths through passive diffusion sampling. Journal of Chromatography B 1096, 56-65.

Peng, J., Qi, M., 2018. Poly(3-hexylthiophene) stationary phase for gas chromatographic separations of aliphatic and aromatic isomers. Journal of Chromatography A 1569, 186-192.

Ruiz-Matute, A.I., Rodríguez-Sánchez, S., Sanz, M.L., Soria, A.C., 2018. Chapter 12 - Chromatographic technique: Gas chromatography (GC), in: Sun, D.-W. (Ed.), Modern Techniques for Food Authentication (Second Edition). Academic Press, pp. 415-458.

Seeley, M.E., Wang, Q., Bacosa, H., Rosenheim, B.E., Liu, Z., 2018. Environmental petroleum pollution analysis using ramped pyrolysis-gas chromatography–mass spectrometry. Organic Geochemistry 124, 180-189.

Sousa, P.F.M., de Waard, A., Åberg, K.M., 2018. Elucidation of chromatographic peak shifts in complex samples using a chemometrical approach. Analytical and Bioanalytical Chemistry 410, 5229-5235.

Walters, C.C., Wang, F.C., Higgins, M.B., Madincea, M.E., 2018. Universal Biomarker Analysis: Aromatic hydrocarbons. Organic Geochemistry 124, 205-214.

Xie, S.-M., Fu, N., Li, L., Yuan, B.-Y., Zhang, J.-H., Li, Y.-X., Yuan, L.-M., 2018. Homochiral metal–organic cage for gas chromatographic separations. Analytical Chemistry 90, 9182-9188.

Zanão, L.R., Diniz Brito dos Santos, B.C., Sequinel, R., Flumignan, D.L., de Oliveira, J.E., 2018. Prediction of relative density, distillation temperatures, flash point, and cetane number of S500 diesel oil using multivariate calibration of gas chromatographic profiles. Energy & Fuels 32, 8108-8114.

Zheng, J., Huang, C., Wang, S., 2018. Challenging pharmaceutical analyses by gas chromatography with vacuum ultraviolet detection. Journal of Chromatography A 1567, 185-190.

IMAGING: SEM, TEM, HIM, AFM

Aubineau, J., El Albani, A., Chi Fru, E., Gingras, M., Batonneau, Y., Buatois, L.A., Geffroy, C., Labanowski, J., Laforest, C., Lemée, L., Mángano, M.G., Meunier, A., Pierson-Wickmann, A.-C., Recourt, P., Riboulleau, A., Trentesaux, A., Konhauser, K.O., 2018. Unusual microbial mat-related structural diversity 2.1 billion years ago and implications for the Francevillian biota. Geobiology 16, 476-497.

Blondeau, M., Sachse, M., Boulogne, C., Gillet, C., Guigner, J.-M., Skouri-Panet, F., Poinsot, M., Ferard, C., Miot, J., Benzerara, K., 2018. Amorphous calcium carbonate granules form within an intracellular compartment in calcifying cyanobacteria. Frontiers in Microbiology 9, 1768. doi: 1710.3389/fmicb.2018.0176.

Bryce, C., Franz-Wachtel, M., Nalpas, N.C., Miot, J., Benzerara, K., Byrne, J.M., Kleindienst, S., Macek, B., Kappler, A., 2018. Proteome response of a metabolically flexible anoxygenic phototroph to Fe(II) oxidation. Applied and Environmental Microbiology 84, Article e01166-01118.

Chen, Z., Jiang, W., Zhang, L., Zha, M., 2018. Organic matter, mineral composition, pore size, and gas sorption capacity of lacustrine mudstones: Implications for the shale oil and gas exploration in the Dongying depression, eastern China. American Association of Petroleum Geologists Bulletin 102, 1565-1600.


Hao, L., Chen, I.C., Oh, J.K., Yegin, C., Nagabandi, N., Talari, J.V., Zhang, L., Akbulut, M., Jiang, B., 2018. Solid-shelled microspheres loaded with solvent as diluents for extracting blockages by heavy-oil and asphaltene precipitates. Fuel 234, 656-663.

Jiang, Z., Zhang, S., Klausen, L.H., Song, J., Li, Q., Wang, Z., Stokke, B.T., Huang, Y., Besenbacher, F., Nielsen, L.P., Dong, M., 2018. In vitro single-cell dissection revealing

the interior structure of cable bacteria. Proceedings of the National Academy of Sciences 115, 8517-8522.

Jiao, K., Yao, S., Zhang, K., Hu, W., Cao, J., 2018. The evolution of nanopores and surface roughness in naturally matured coals in South China: An atomic force microscopy and image processing study. Fuel 234, 1123-1131.

Kenkel, S., Mittal, A., Mittal, S., Bhargava, R., 2018. Probe–sample interaction-independent atomic force microscopy–infrared spectroscopy: Toward robust nanoscale compositional mapping. Analytical Chemistry 90, 8845-8855.

Kumar, S., Das, S., Bastia, R., Ojha, K., 2018. Mineralogical and morphological characterization of Older Cambay Shale from North Cambay Basin, India: Implication for shale oil/gas development. Marine and Petroleum Geology 97, 339-354.

Li, C., Ostadhassan, M., Guo, S., Gentzis, T., Kong, L., 2018. Application of PeakForce tapping mode of atomic force microscope to characterize nanomechanical properties of organic matter of the Bakken Shale. Fuel 233, 894-910.

Ma, L., Slater, T., Dowey, P.J., Yue, S., Rutter, E.H., Taylor, K.G., Lee, P.D., 2018. Hierarchical integration of porosity in shales. Scientific Reports 8, Article 11683.

Mao, W., Guo, S., 2018. Comparison of factors influencing pore size distributions in marine, terrestrial, and transitional shales of similar maturity in China. Energy & Fuels 32, 8145-8153.

Mastalerz, M., Wei, L., Drobniak, A., Schimmelmann, A., Schieber, J., 2018. Responses of specific surface area and micro- and mesopore characteristics of shale and coal to heating at elevated hydrostatic and lithostatic pressures. International Journal of Coal Geology 197, 20-30.

Wei, M., Xu, T., Bei, K., Jin, G., Liu, X., Cao, Y., Liu, N., 2018. Effect of the temperature and pressure conditions on the formation of authigene carbonate minerals and iron sulfide in a microorganisms system. Acta Sedimentologica Sinica 86, 664-673.

Wu, J., Hu, Z., Xie, J., Liu, Z., Zhao, J., 2018. Macro–micro occurrence mechanism of organic matters in Wufeng–Longmaxi shale in the Sichuan Basin and its peripheral areas. Natural Gas Industry 38, 23-32.

Yuan, G., Jin, Z., Zuo, X., Xue, Z., Yan, F., Dong, Z., Cong, Y., Li, X., 2018. Effect of carbonaceous precursors on the structure of mesophase pitches and their derived cokes. Energy & Fuels 32, 8329-8339.

Zheng, S., Yao, Y., Liu, D., Cai, Y., Liu, Y., 2018. Characterizations of full-scale pore size distribution, porosity and permeability of coals: A novel methodology by nuclear magnetic resonance and fractal analysis theory. International Journal of Coal Geology 196, 148-158.

IMAGING: XRAY CT

Adeleye, J.O., Akanji, L.T., 2018. Pore-scale analyses of heterogeneity and representative elementary volume for unconventional shale rocks using statistical tools. Journal of Petroleum Exploration and Production Technology 8, 753-765.

Keating, J.N., Marquart, C.L., Marone, F., Donoghue, P.C.J., 2018. The nature of aspidin and the evolutionary origin of bone. Nature Ecology & Evolution 2, 1501-1506.

Wang, Y., Yuan, Y., Rahman, S.S., Arns, C., 2018. Semi-quantitative multiscale modelling and flow simulation in a nanoscale porous system of shale. Fuel 234, 1181-1192.

LIQUID CHROMATOGRAPHY/LC-MS/SFC

Albergamo, V., Helmus, R., de Voogt, P., 2018. Direct injection analysis of polar micropollutants in natural drinking water sources with biphenyl liquid chromatography coupled to high-resolution time-of-flight mass spectrometry. Journal of Chromatography A 1569, 53-61.

Celma, A., Bijlsma, L., López, F.J., Sancho, J.V., 2018. Development of a Retention Time Interpolation scale (RTi) for liquid chromatography coupled to mass spectrometry in both positive and negative ionization modes. Journal of Chromatography A 1568, 101-107.

Chen, J., Chen, D., Zhang, X., Wang, M., Chen, B., An, D., Xu, L., Lyu, Q., 2018. Quantification of alcohols, diols and glycerol in fermentation with an instantaneous derivatization using trichloroacetyl isocyanante via liquid chromatography-mass spectrometry. Journal of Chromatography A 1568, 22-28.

Guo, W., Li, B., Chi, H., Ramsey, E.D., 2018. A dedicated mass spectrometer tuning method for SFC–MS and evaluation of two different linear restrictor types used in the operation of a split flow pre-back pressure regulator SFC–MS interface. Chromatographia 81, 1257-1267.

Kusch, S., Shah Walter, S.R., Hemingway, J.D., Pearson, A., 2018. Improved chromatography reveals multiple new bacteriohopanepolyol isomers in marine sediments. Organic Geochemistry 124, 12-21.

Kwiatkowski, M., Krösser, D., Wurlitzer, M., Steffen, P., Barcaru, A., Krisp, C., Horvatovich, P., Bischoff, R., Schlüter, H., 2018. Application of displacement chromatography to online two-dimensional liquid chromatography coupled to tandem mass spectrometry improves peptide separation efficiency and detectability for the analysis of complex proteomes. Analytical Chemistry 90, 9951-9958.

Li, Y., Nesterenko, P.N., Stanley, R., Paull, B., Macka, M., 2018. High sensitivity deep-UV LED-based z-cell photometric detector for capillary liquid chromatography. Analytica Chimica Acta 1032, 197-202.

Lozano-Sánchez, J., Borrás-Linares, I., Sass-Kiss, A., Segura-Carretero, A., 2018. Chapter 13 - Chromatographic technique: High-performance liquid chromatography (HPLC), in: Sun, D.-W. (Ed.), Modern Techniques for Food Authentication (Second Edition). Academic Press, pp. 459-526.

Qian, K., Yang, Z., Zhang, F., Yang, B., Dasgupta, P.K., 2018. Low-bleed silica-based stationary phase for hydrophilic interaction liquid chromatography. Analytical Chemistry 90, 8750-8755.

Rama-Corredor, O., Cortina, A., Martrat, B., Lopez, J.F., Grimalt, J.O., 2018. Removal of bias in C37 alkenone-based sea surface temperature measurements by high-performance liquid chromatography fractionation. Journal of Chromatography A 1567, 90-98.


Zhu, Q.-F., Yan, J.-W., Zhang, T.-Y., Xiao, H.-M., Feng, Y.-Q., 2018. Comprehensive screening and identification of fatty acid esters of hydroxy fatty acids in plant tissues by chemical isotope labeling-assisted liquid chromatography–mass spectrometry. Analytical Chemistry 90, 10056-10063.

Zoccali, M., Giuffrida, D., Salafia, F., Giofrè, S.V., Mondello, L., 2018. Carotenoids and apocarotenoids determination in intact human blood samples by online supercritical fluid extraction-supercritical fluid chromatography-tandem mass spectrometry. Analytica Chimica Acta 1032, 40-47.

MASS SPECTROSCOPY/ICR-FTMS/ORBITRAP

Bao, H., Niggemann, J., Luo, L., Dittmar, T., Kao, S.-J., 2018. Molecular composition and origin of water-soluble organic matter in marine aerosols in the Pacific off China. Atmospheric Environment 191, 27-35.

Caricasole, P., Hatcher, P.G., Ohno, T., 2018. Biodegradation of crop residue-derived organic matter is influenced by its heteroatomic stoichiometry and molecular composition. Applied Soil Ecology 130, 21-25.

Celis-Cornejo, C.M., Pérez-Martínez, D.J., Orrego-Ruiz, J.A., Baldovino-Medrano, V.G., 2018. Identification of refractory weakly basic nitrogen compounds in a deeply hydrotreated vacuum gas oil and assessment of the effect of some representative species over the performance of a Ni–MoS2/Y-zeolite–alumina catalyst in phenanthrene hydrocracking. Energy & Fuels 32, 8715-8726.


Guillemette, R., Kaneko, R., Blanton, J., Tan, J., Witt, M., Hamilton, S., Allen, E.E., Medina, M., Hamasaki, K., Koch, B.P., Azam, F., 2018. Bacterioplankton drawdown of coral mass-spawned organic matter. The ISME Journal 12, 2238-2251.

Han, Y., Poetz, S., Mahlstedt, N., Karger, C., Horsfield, B., 2018. Fractionation and origin of NyOx and Ox compounds in the Barnett Shale sequence of the Marathon 1 Mesquite well, Texas. Marine and Petroleum Geology 97, 517-524.

Ji, H., Li, S., Greenwood, P., Zhang, H., Pang, X., Xu, T., He, N., Shi, Q., 2018. Geochemical characteristics and significance of heteroatom compounds in lacustrine oils of the Dongpu Depression (Bohai Bay Basin, China) by negative-ion Fourier transform ion cyclotron resonance mass spectrometry. Marine and Petroleum Geology 97, 568-591.

Jiménez-Morillo, N.T., González-Pérez, J.A., Almendros, G., De la Rosa, J.M., Waggoner, D.C., Jordán, A., Zavala, L.M., González-Vila, F.J., Hatcher, P.G., 2018. Ultra-high resolution mass spectrometry of physical speciation patterns of organic matter in fire-affected soils. Journal of Environmental Management 225, 139-147.

Kostyukevich, Y., Zherebker, A., Vlaskin, M.S., Borisova, L., Nikolaev, E., 2018. Microprobe for the thermal analysis of crude oil coupled to photoionization Fourier transform mass spectrometry. Analytical Chemistry 90, 8756-8763.

Rocha, Y.d.S., Pereira, R.C.L., Mendonça Filho, J.G., 2018. Geochemical characterization of lacustrine and marine oils from off-shore Brazilian sedimentary basins using negative-ion electrospray Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR-MS). Organic Geochemistry 124, 29-45.

Schaepe, K., Bhandari, D.R., Werner, J., Henss, A., Pirkl, A., Kleine-Boymann, M., Rohnke, M., Wenisch, S., Neumann, E., Janek, J., Spengler, B., 2018. Imaging of lipids in native human bone sections using TOF–secondary ion mass spectrometry, atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization Orbitrap mass spectrometry, and Orbitrap–secondary ion mass spectrometry. Analytical Chemistry 90, 8856-8864.

Zhou, Z., Chen, X., Ma, H., Liu, C., Zhou, C., Qi, F., 2019. Real-time monitoring biomass pyrolysis via on-line photoionization ultrahigh-resolution mass spectrometry. Fuel 235, 962-971.

Zuth, C., Vogel, A.L., Ockenfeld, S., Huesmann, R., Hoffmann, T., 2018. Ultrahigh-resolution mass spectrometry in real time: Atmospheric pressure chemical ionization Orbitrap mass spectrometry of atmospheric organic aerosol. Analytical Chemistry 90, 8816-8823.

MASS SPECTROSCOPY/OTHER

Bacon, C.W., Hinton, D.M., Mitchell, T.R., 2018. Screening of Bacillus mojavensis biofilms and biosurfactants using laser ablation electrospray ionization mass spectroscopy. Journal of Applied Microbiology 125, 867-875.

Burckhardt, I., Zimmermann, S., 2018. Susceptibility testing of bacteria using MALDI-TOF mass spectrometry. Frontiers in Microbiology 9, 1744. doi: 1710.3389/fmicb.2018.01744.

De Vijlder, T., Valkenborg, D., Lemière, F., Romijn, E.P., Laukens, K., Cuyckens, F., 2018. A tutorial in small molecule identification via electrospray ionization-mass spectrometry: The practical art of structural elucidation. Mass Spectrometry Reviews 37, 607-629.

Duncombe, T.A., Raad, M.D., Bowen, B.P., Singh, A.K., Northen, T.R., 2018. Insulator nanostructure desorption ionization mass spectrometry. Analytical Chemistry 90, 9657-9661.

English, S.L., Forsythe, J.G., 2018. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of model prebiotic peptides: Optimization of sample preparation. Rapid Communications in Mass Spectrometry 32, 1507-1513.

Holzlechner, M., Bonta, M., Lohninger, H., Limbeck, A., Marchetti-Deschmann, M., 2018. Multisensor imaging—from sample preparation to integrated multimodal interpretation of LA-ICPMS and MALDI MS imaging data. Analytical Chemistry 90, 8831-8837.

Liigand, P., Liigand, J., Cuyckens, F., Vreeken, R.J., Kruve, A., 2018. Ionisation efficiencies can be predicted in complicated biological matrices: A proof of concept. Analytica Chimica Acta 1032, 68-74.

Lin, Z., Cai, Z., 2018. Negative ion laser desorption/ionization time-of-flight mass spectrometric analysis of small molecules by using nanostructured substrate as matrices. Mass Spectrometry Reviews 37, 681-696.

Lu, H., Zhang, H., Chingin, K., Xiong, J., Fang, X., Chen, H., 2018. Ambient mass spectrometry for food science and industry. TrAC Trends in Analytical Chemistry 107, 99-115.

Patil, A.A., Chiang, C.-K., Wen, C.-H., Peng, W.-P., 2018. Forced dried droplet method for MALDI sample preparation. Analytica Chimica Acta 1031, 128-133.

Schaepe, K., Bhandari, D.R., Werner, J., Henss, A., Pirkl, A., Kleine-Boymann, M., Rohnke, M., Wenisch, S., Neumann, E., Janek, J., Spengler, B., 2018. Imaging of lipids in native human bone sections using TOF–secondary ion mass spectrometry, atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization Orbitrap mass spectrometry, and Orbitrap–secondary ion mass spectrometry. Analytical Chemistry 90, 8856-8864.

Tucker, L.H., Conde-González, A., Cobice, D., Hamm, G.R., Goodwin, R.J.A., Campbell, C.J., Clarke, D.J., Mackay, C.L., 2018. MALDI matrix application utilizing a modified 3D printer for accessible high resolution mass spectrometry imaging. Analytical Chemistry 90, 8742-8749.

Wang, J., Wang, Z., Liu, F., Cai, L., Pan, J.-b., Li, Z., Zhang, S., Chen, H.-Y., Zhang, X., Mo, Y., 2018. Vacuum ultraviolet laser desorption/ionization mass spectrometry imaging of single cells with submicron craters. Analytical Chemistry 90, 10009-10015.

Wang, S.-K., Wei, X.-Y., Li, S., Liu, F.-J., Wang, Y.-G., Li, Z.-K., Shi, C., Yang, Z., Zong, Z.-M., 2018. Rapid analysis of carboxylic acids and esters with a direct analysis in real time ion source. Rapid Communications in Mass Spectrometry 32, 1521-1528.

METABOLOMICS/LIPIDOMICS

Chaleckis, R., Meister, I., Zhang, P., Wheelock, C.E., 2019. Challenges, progress and promises of metabolite annotation for LC–MS-based metabolomics. Current Opinion in Biotechnology 55, 44-50.

Chao, Y., Gao, S., Wang, X., Li, N., Zhao, H., Wen, X., Lou, Z., Dong, X., 2018. Untargeted lipidomics based on UPLC-QTOF-MS/MS and structural characterization reveals dramatic compositional changes in serum and renal lipids in mice with glyoxylate-induced nephrolithiasis. Journal of Chromatography B 1095, 258-266.

Cheah, Y.E., Young, J.D., 2018. Isotopically nonstationary metabolic flux analysis (INST-MFA): putting theory into practice. Current Opinion in Biotechnology 54, 80-87.


Drouin, N., Pezzatti, J., Gagnebin, Y., González-Ruiz, V., Schappler, J., Rudaz, S., 2018. Effective mobility as a robust criterion for compound annotation and identification in metabolomics: Toward a mobility-based library. Analytica Chimica Acta 1032, 178-187.

Keating, J.E., Glish, G.L., 2018. Dual emitter nano-electrospray ionization coupled to differential ion mobility spectrometry-mass spectrometry for shotgun lipidomics. Analytical Chemistry 90, 9117-9124.

Knittelfelder, O., Traikov, S., Vvedenskaya, O., Schuhmann, A., Segeletz, S., Shevchenko, A., Shevchenko, A., 2018. Shotgun lipidomics combined with laser capture microdissection: A tool to analyze histological zones in cryosections of tissues. Analytical Chemistry 90, 9868-9878.

Murphy, R.C., 2018. Challenges in mass spectrometry-based lipidomics of neutral lipids. TrAC Trends in Analytical Chemistry 107, 91-98.

Navarro-Reig, M., Jaumot, J., Tauler, R., 2018. An untargeted lipidomic strategy combining comprehensive two-dimensional liquid chromatography and chemometric analysis. Journal of Chromatography A 1568, 80-90.

Schwechheimer, S.K., Becker, J., Wittmann, C., 2018. Towards better understanding of industrial cell factories: novel approaches for 13C metabolic flux analysis in complex nutrient environments. Current Opinion in Biotechnology 54, 128-137.

Surowiec, I., Johansson, E., Stenlund, H., Rantapää-Dahlqvist, S., Bergström, S., Normark, J., Trygg, J., 2018. Quantification of run order effect on chromatography - mass spectrometry profiling data. Journal of Chromatography A 1568, 229-234.

Takahashi, M., Izumi, Y., Iwahashi, F., Nakayama, Y., Iwakoshi, M., Nakao, M., Yamato, S., Fukusaki, E., Bamba, T., 2018. Highly accurate detection and identification methodology of xenobiotic metabolites using stable isotope labeling, data mining techniques, and time-dependent profiling based on LC/HRMS/MS. Analytical Chemistry 90, 9068-9076.

Tang, C.-H., Shi, S.-H., Lin, C.-Y., Li, H.-H., Wang, W.-H., 2019. Using lipidomic methodology to characterize coral response to herbicide contamination and develop an early biomonitoring model. Science of The Total Environment 648, 1275-1283.

Wen, Y., Amos, R.I.J., Talebi, M., Szucs, R., Dolan, J.W., Pohl, C.A., Haddad, P.R., 2018. Retention index prediction using quantitative structure–retention relationships for improving structure identification in nontargeted metabolomics. Analytical Chemistry 90, 9434-9440.

Xiong, W., Lo, J., Chou, K.J., Wu, C., Magnusson, L., Dong, T., Maness, P., 2018. Isotope-assisted metabolite analysis sheds light on central carbon metabolism of a model cellulolytic bacterium Clostridium thermocellum. Frontiers in Microbiology 9, 1947. doi: 1910.3389/fmicb.2018.01947.

Zhang, X.-C., Zang, Q., Zhao, H., Ma, X., Pan, X., Feng, J., Zhang, S., Zhang, R., Abliz, Z., Zhang, X., 2018. Combination of droplet extraction and pico-ESI-MS allows the identification of metabolites from single cancer cells. Analytical Chemistry 90, 9897-9903.

PUPPYOMICS

Losey, R.J., Nomokonova, T., Gusev, A.V., Bachura, O.P., Fedorova, N.V., Kosintsev, P.A., Sablin, M.V., 2018. Dogs were domesticated in the Arctic: Culling practices and dog sledding at Ust’-Polui. Journal of Anthropological Archaeology 51, 113-126.

Archaeological/Art Organic Chemistry

Arranz-Otaegui, A., Gonzalez Carretero, L., Ramsey, M.N., Fuller, D.Q., Richter, T., 2018. Archaeobotanical evidence reveals the origins of bread 14,400 years ago in northeastern Jordan. Proceedings of the National Academy of Sciences 115, 7925-7930.

Balezin, M., Baryshnikova, K.V., Kapitanova, P., Evlyukhin, A.B., 2018. Electromagnetic properties of the Great Pyramid: First multipole resonances and energy concentration. Journal of Applied Physics 124, 034903.

Greco, E., El-Aguizy, O., Ali, M.F., Foti, S., Cunsolo, V., Saletti, R., Ciliberto, E., 2018. Proteomic analyses on an ancient Egyptian cheese and biomolecular evidence of Brucellosis. Analytical Chemistry 90, 9673-9676.

Harney, É., May, H., Shalem, D., Rohland, N., Mallick, S., Lazaridis, I., Sarig, R., Stewardson, K., Nordenfelt, S., Patterson, N., Hershkovitz, I., Reich, D., 2018. Ancient DNA from Chalcolithic Israel reveals the role of population mixture in cultural transformation. Nature Communications 9, Article 3336.

Lengfelder, F., Grupe, G., Stallauer, A., Huth, R., Söllner, F., 2019. Modelling strontium isotopes in past biospheres – Assessment of bioavailable 87Sr/86Sr ratios in local archaeological vertebrates based on environmental signatures. Science of The Total Environment 648, 236-252.

Mazzoli, R., Giuffrida, M.G., Pessione, E., 2018. Back to the past—forever young: cutting-edge biochemical and microbiological tools for cultural heritage conservation. Applied Microbiology and Biotechnology 102, 6815-6825.

Okamoto, S., Honda, T., Miyakoshi, T., Han, B., Sablier, M., 2018. Application of pyrolysis-comprehensive gas chromatography/mass spectrometry for identification of Asian lacquers. Talanta 189, 315-323.

Ryan, S.E., Reynard, L.M., Crowley, Q.G., Snoeck, C., Tuross, N., 2018. Early medieval reliance on the land and the local: An integrated multi-isotope study (87Sr/86Sr, δ18O, δ13C, δ15N) of diet and migration in Co. Meath, Ireland. Journal of Archaeological Science 98, 59-71.

Silva, C.S., Pimentel, M.F., Amigo, J.M., García-Ruiz, C., Ortega-Ojeda, F., 2018. Chemometric approaches for document dating: Handling paper variability. Analytica Chimica Acta 1031, 28-37.

Star, B., Barrett, J.H., Gondek, A.T., Boessenkool, S., 2018. Ancient DNA reveals the chronology of walrus ivory trade from Norse Greenland. Proceedings of the Royal Society B: Biological Sciences 285, Article 20180978.

Tafuri, M.A., Goude, G., Manzi, G., 2018. Isotopic evidence of diet variation at the transition between classical and post-classical times in Central Italy. Journal of Archaeological Science: Reports 21, 496-503.

Biochemistry


Jiang, Z., Zhang, S., Klausen, L.H., Song, J., Li, Q., Wang, Z., Stokke, B.T., Huang, Y., Besenbacher, F., Nielsen, L.P., Dong, M., 2018. In vitro single-cell dissection revealing the interior structure of cable bacteria. Proceedings of the National Academy of Sciences 115, 8517-8522.

Meneghin, E., Volpato, A., Cupellini, L., Bolzonello, L., Jurinovich, S., Mascoli, V., Carbonera, D., Mennucci, B., Collini, E., 2018. Coherence in carotenoid-to-chlorophyll energy transfer. Nature Communications 9, Article 3160.

Sinninghe Damsté, J.S., Rijpstra, W.I.C., Foesel, B.U., Huber, K.J., Overmann, J., Nakagawa, S., Kim, J.J., Dunfield, P.F., Dedysh, S.N., Villanueva, L., 2018. An overview of the occurrence of ether- and ester-linked iso-diabolic acid membrane lipids in microbial cultures of the Acidobacteria: Implications for brGDGT paleoproxies for temperature and pH. Organic Geochemistry 124, 63-76.

Wunderlich, A., Heipieper, H.J., Elsner, M., Einsiedl, F., 2018. Solvent stress-induced changes in membrane fatty acid composition of denitrifying bacteria reduce the extent of nitrogen

stable isotope fractionation during denitrification. Geochimica et Cosmochimica Acta 239, 275-283.

Biodegradation

Bücker, F., de Moura, T.M., da Cunha, M.E., de Quadros, P.D., Beker, S.A., Cazarolli, J.C., Caramão, E.B., Frazzon, A.P.G., Bento, F.M., 2018. Evaluation of the deteriogenic microbial community using qPCR, n-alkanes and FAMEs biodegradation in diesel, biodiesel and blends (B5, B10, and B50) during storage. Fuel 233, 911-917.

Detman, A., Bucha, M., Simoneit, B.R.T., Mielecki, D., Piwowarczyk, C., Chojnacka, A., Błaszczyk, M.K., Jędrysek, M.O., Marynowski, L., Sikora, A., 2018. Lignite biodegradation under conditions of acidic molasses fermentation. International Journal of Coal Geology 196, 274-287.

Li, F., Chang, Z., Khaing, K., Zhou, Y., Zhao, H., Liang, N., Zhou, D., Pan, B., Steinberg, C.E.W., 2019. Organic matter protection by kaolinite over bio-decomposition as suggested by lignin and solvent-extractable lipid molecular markers. Science of The Total Environment 647, 570-576.

McFarlin, K.M., Perkins, M.J., Field, J.A., Leigh, M.B., 2018. Biodegradation of crude oil and Corexit 9500 in Arctic seawater. Frontiers in Microbiology 9, 1788. doi: 1710.3389/fmicb.2018.01788.

Wang, J., Liang, J., Gao, S., 2018. Biodegradation of lignin monomers vanillic, p-coumaric, and syringic acid by the bacterial strain, Sphingobacterium sp. HY-H. Current Microbiology 75, 1156-1164.

BIODEGRADATION PATHWAYS/GENOMICS

Chen, G., Shouakar-Stash, O., Phillips, E., Justicia-Leon, S.D., Gilevska, T., Sherwood Lollar, B., Mack, E.E., Seger, E.S., Löffler, F.E., 2018. Dual carbon–chlorine isotope analysis indicates distinct anaerobic dichloromethane degradation pathways in two members of Peptococcaceae. Environmental Science & Technology 52, 8607-8616.

Li, X., Pan, Y., Hu, S., Cheng, Y., Wang, Y., Wu, K., Zhang, S., Yang, S., 2018. Diversity of phenanthrene and benz[a]anthracene metabolic pathways in white rot fungus Pycnoporus sanguineus 14. International Biodeterioration & Biodegradation 134, 25-30.

Sazykin, I.S., Sazykina, M.A., Khmelevtsova, L.E., Seliverstova, E.Y., Karchava, K.S., Zhuravleva, M.V., 2018. Antioxidant enzymes and reactive oxygen species level of the Achromobacter xylosoxidans bacteria during hydrocarbons biotransformation. Archives of Microbiology 200, 1057-1065.

Biofuels/Biomass

Bröker, J.N., Müller, B., van Deenen, N., Prüfer, D., Schulze Gronover, C., 2018. Upregulating the mevalonate pathway and repressing sterol synthesis in Saccharomyces cerevisiae enhances the production of triterpenes. Applied Microbiology and Biotechnology 102, 6923-6934.

Lopes, A.M., Ferreira Filho, E.X., Moreira, L.R.S., 2018. An update on enzymatic cocktails for lignocellulose breakdown. Journal of Applied Microbiology 125, 632-645.

Nelabhotla, A.B.T., Dinamarca, C., 2018. Electrochemically mediated CO2 reduction for bio-methane production: a review. Reviews in Environmental Science and Bio/Technology 17, 531-551.

Oliver, J.P., Schilling, J.S., 2018. Harnessing fungi to mitigate CH4 in natural and engineered systems. Applied Microbiology and Biotechnology 102, 7365-7375.

Rahman, M.M., Liu, R., Cai, J., 2018. Catalytic fast pyrolysis of biomass over zeolites for high quality bio-oil – A review. Fuel Processing Technology 180, 32-46.

Straub, C.T., Counts, J.A., Nguyen, D.M.N., Wu, C.-H., Zeldes, B.M., Crosby, J.R., Conway, J.M., Otten, J.K., Lipscomb, G.L., Schut, G.J., Adams, M.W.W., Kelly, R.M., 2018. Biotechnology of extremely thermophilic archaea. FEMS Microbiology Reviews 42, 543-578.

Wirth, R., Lakatos, G., Böjti, T., Maróti, G., Bagi, Z., Rákhely, G., Kovács, K.L., 2018. Anaerobic gaseous biofuel production using microalgal biomass – A review. Anaerobe 52, 1-8.


Biogeochemistry


Garcia-Tigreros, F., Kessler, J.D., 2018. Limited acute influence of aerobic methane oxidation on ocean carbon dioxide and pH in Hudson Canyon, northern U.S. Atlantic Margin. Journal of Geophysical Research: Biogeosciences 123, 2135-2144.

Hermoso, M., Lecasble, M., 2018. The effect of salinity on the biogeochemistry of the coccolithophores with implications for coccolith-based isotopic proxies. Biogeosciences DIscussions 2018.

Kumar, S., Herrmann, M., Blohm, A., Hilke, I., Frosch, T., Trumbore, S.E., Küsel, K., 2018. Thiosulfate- and hydrogen-driven autotrophic denitrification by a microbial consortium

enriched from groundwater of an oligotrophic limestone aquifer. FEMS Microbiology Ecology 94, Article fiy141.

Lee, C.J.D., McMullan, P.E., O’Kane, C.J., Stevenson, A., Santos, I.C., Roy, C., Ghosh, W., Mancinelli, R.L., Mormile, M.R., McMullan, G., Banciu, H.L., Fares, M.A., Benison, K.C., Oren, A., Dyall-Smith, M.L., Hallsworth, J.E., 2018. NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats. FEMS Microbiology Reviews 42, 672-693.

Lein, A.Y., Ivanov, M.V., 2018. Interaction of biogeochemical sulfur and carbon cycles in marine basins by the example of the Black Sea. Doklady Earth Sciences 481, 939-942.

Makita, H., 2018. Iron-oxidizing bacteria in marine environments: recent progresses and future directions. World Journal of Microbiology and Biotechnology 34, Article 110.

März, C., Riedinger, N., Sena, C., Kasten, S., 2018. Phosphorus dynamics around the sulphate-methane transition in continental margin sediments: Authigenic apatite and Fe(II) phosphates. Marine Geology 404, 84-96.

Mo, Y., Zhang, W., Yang, J., Lin, Y., Yu, Z., Lin, S., 2018. Biogeographic patterns of abundant and rare bacterioplankton in three subtropical bays resulting from selective and neutral processes. The ISME Journal 12, 2198-2210.

Otwell, A.E., Callister, S.J., Sherwood, R.W., Zhang, S., Goldman, A.R., Smith, R.D., Richardson, R.E., 2018. Physiological and proteomic analyses of Fe(III)-reducing co-cultures of Desulfotomaculum reducens MI-1 and Geobacter sulfurreducens PCA. Geobiology 16, 522-539.

Ray, A.E., Connon, S.A., Neal, A.L., Fujita, Y., Cummings, D.E., Ingram, J.C., Magnuson, T.S., 2018. Metal transformation by a novel Pelosinus isolate from a subsurface environment. Frontiers in Microbiology 9, 1689. doi: 1610.3389/fmicb.2018.01689.

Shrivastava, A., Patel, V.K., Tang, Y., Yost, S.C., Dewhirst, F.E., Berg, H.C., 2018. Cargo transport shapes the spatial organization of a microbial community. Proceedings of the National Academy of Sciences 115, 8633-8638.

Sparrow, K.J., Kessler, J.D., 2018. Comment on “The origin of methane in the East Siberian Arctic Shelf unraveled with triple isotope analysis” by Sapart et al. (2017). Biogeosciences 15, 4777-4779.

Stawiarski, B., Otto, S., Thiel, V., Gräwe, U., Loick-Wilde, N., Wittenborn, A.K., Schloemer, S., Wäge, J., Rehder, G., Labrenz, M., Wasmund, N., Schmale, O., 2018. Controls on zooplankton methane production in the central Baltic Sea. Biogeosciences DIscussions 2018, 1-31.

ter Heijne, A., de Rink, R., Liu, D., Klok, J.B.M., Buisman, C.J.N., 2018. Bacteria as an electron shuttle for sulfide oxidation. Environmental Science & Technology Letters 5, 495-499.


Yao, H., Hong, W.-L., Panieri, G., Sauer, S., Torres, M.E., Lehmann, M.F., Gründger, F., Niemann, H., 2018. Fracture-controlled fluid transport supports microbial methane oxidizing communities at the Vestnesa Ridge Biogeosciences Discussions 2018, 1-17.

Zhang, Y., Douglas, G.B., Kaksonen, A.H., Cui, L., Ye, Z., 2019. Microbial reduction of nitrate in the presence of zero-valent iron. Science of The Total Environment 646, 1195-1203.

BIOFILM/MICROBIAL INDUCED CORROSION


De Falco, N., Boano, F., Bogler, A., Bar-Zeev, E., Arnon, S., 2018. Influence of stream-subsurface exchange flux and bacterial biofilms on oxygen consumption under nutrient-rich conditions. Journal of Geophysical Research: Biogeosciences 123, 2021-2034.

Dragoš, A., Lakshmanan, N., Martin, M., Horváth, B., Maróti, G., Falcón García, C., Lieleg, O., Kovács, Á.T., 2018. Evolution of exploitative interactions during diversification in Bacillus subtilis biofilms. FEMS Microbiology Ecology 94, Article fix155.

Kent, A.G., Garcia, C.A., Martiny, A.C., 2018. Increased biofilm formation due to high-temperature adaptation in marine Roseobacter. Nature Microbiology 3, 989-995.

Li, C., Wang, L., Liu, H., 2018. Enhanced redox conductivity and enriched Geobacteraceae of exoelectrogenic biofilms in response to static magnetic field. Applied Microbiology and Biotechnology 102, 7611-7621.

Lv, M., Du, M., 2018. A review: microbiologically influenced corrosion and the effect of cathodic polarization on typical bacteria. Reviews in Environmental Science and Bio/Technology 17, 431-446.

MICROBIAL MEDIATION OF MINERAL FORMATION/DEGRADATION


Brasier, A., Wacey, D., Rogerson, M., Guagliardo, P., Saunders, M., Kellner, S., Mercedes-Martin, R., Prior, T., Taylor, C., Matthews, A., Reijmer, J., 2018. A microbial role in the construction of Mono Lake carbonate chimneys? Geobiology 16, 540-555.

Drake, H., Whitehouse, M.J., Heim, C., Reiners, P.W., Tillberg, M., Hogmalm, K.J., Dopson, M., Broman, C., Åström, M.E., 2018. Unprecedented 34S-enrichment of pyrite formed following microbial sulfate reduction in fractured crystalline rocks. Geobiology 16, 556-574.

Li, T., Hu, Y., Zhang, B., 2018. Biomineralization induced by Colletotrichum acutatum: A potential strategy for cultural relic bioprotection. Frontiers in Microbiology 9, 1884. doi: 1810.3389/fmicb.2018.01884.

Toshchakov, S.V., Lebedinsky, A.V., Sokolova, T.G., Zavarzina, D.G., Korzhenkov, A.A., Teplyuk, A.V., Chistyakova, N.I., Rusakov, V.S., Bonch-Osmolovskaya, E.A., Kublanov, I.V., Gavrilov, S.N., 2018. Genomic insights into energy metabolism of Carboxydocella thermautotrophica coupling hydrogenogenic CO oxidation with the reduction of Fe(III) minerals. Frontiers in Microbiology 9, 1759. doi: 1710.3389/fmicb.2018.01759.

Carbon Cycle

Abdul-Aziz, O.I., Ishtiaq, K.S., Tang, J., Moseman-Valtierra, S., Kroeger, K.D., Gonneea, M.E., Mora, J., Morkeski, K., 2018. Environmental controls, emergent scaling, and predictions of greenhouse gas (GHG) fluxes in coastal salt marshes. Journal of Geophysical Research: Biogeosciences 123, 2234-2256.

Arora, V.K., Melton, J.R., Plummer, D., 2018. An assessment of natural methane fluxes simulated by the CLASS-CTEM model. Biogeosciences 15, 4683-4709.

Chen, Z., Li, Y., Du, J., Zheng, G., Li, Y., Gao, X., Cui, Y., Zhou, X., Liu, L., Liu, H., Xie, C., Yan, L., Wang, C., 2018. Carbon isotope variations in inorganic carbon materials: Implications for mud volcanic carbon cycling in the northern Tianshan fold zone, Xinjiang, China. Applied Geochemistry 97, 32-39.

Ni, X., Groffman, P.M., 2018. Declines in methane uptake in forest soils. Proceedings of the National Academy of Sciences 115, 8587-8590.

Rinne, J., Tuittila, E.-S., Peltola, O., Li, X., Raivonen, M., Alekseychik, P., Haapanala, S., Pihlatie, M., Aurela, M., Mammarella, I., Vesala, T., 2018. Temporal variation of ecosystem scale methane emission from a boreal fen in relation to temperature, water table position, and carbon dioxide fluxes. Global Biogeochemical Cycles 32, 1087-1106.

Yan, F., Sillanpää, M., Kang, S., Aho, K.S., Qu, B., Wei, D., Li, X., Li, C., Raymond, P.A., 2018. Lakes on the Tibetan Plateau as conduits of greenhouse gases to the atmosphere. Journal of Geophysical Research: Biogeosciences 123, 2091-2103.

Carbon Sequestration

Huang, L., Ning, Z., Wang, Q., Ye, H., Chen, Z., Sun, Z., Sun, F., Qin, H., 2018. Enhanced gas recovery by CO2 sequestration in marine shale: a molecular view based on realistic kerogen model. Arabian Journal of Geosciences 11, Article 404.

Iglauer, S., 2018. Optimum storage depths for structural CO2 trapping. International Journal of Greenhouse Gas Control 77, 82-87.

Menefee, A.H., Giammar, D.E., Ellis, B.R., 2018. Permanent CO2 trapping through localized and chemical gradient-driven basalt carbonation. Environmental Science & Technology 52, 8954-8964.

Mi, Z., Wang, F., Yang, Y., Wang, F., Hu, T., Tian, H., 2018. Evaluation of the potentiality and suitability for CO2 geological storage in the Junggar Basin, northwestern China. International Journal of Greenhouse Gas Control 78, 62-72.

Ren, B., 2018. Local capillary trapping in carbon sequestration: Parametric study and implications for leakage assessment. International Journal of Greenhouse Gas Control 78, 135-147.

Rhino, K., Loisy, C., Cerepi, A., Garcia, B., Rouchon, V., Khamlichi, A.E., Noirez, S., 2018. Characterization and quantification of a CO2 and CH4 leakage experiment from a well into the carbonate vadose zone. International Journal of Greenhouse Gas Control 77, 55-69.

Climate Change


Bond-Lamberty, B., Bailey, V.L., Chen, M., Gough, C.M., Vargas, R., 2018. Globally rising soil heterotrophic respiration over recent decades. Nature 560, 80-83.

Comyn-Platt, E., Hayman, G., Huntingford, C., Chadburn, S.E., Burke, E.J., Harper, A.B., Collins, W.J., Webber, C.P., Powell, T., Cox, P.M., Gedney, N., Sitch, S., 2018. Carbon budgets for 1.5 and 2 °C targets lowered by natural wetland and permafrost feedbacks. Nature Geoscience 11, 568-573.

Doetterl, S., Berhe, A.A., Arnold, C., Bodé, S., Fiener, P., Finke, P., Fuchslueger, L., Griepentrog, M., Harden, J.W., Nadeu, E., Schnecker, J., Six, J., Trumbore, S., Van Oost, K., Vogel, C., Boeckx, P., 2018. Links among warming, carbon and microbial dynamics mediated by soil mineral weathering. Nature Geoscience 11, 589-593.

Hopwood, M.J., Carroll, D., Browning, T.J., Meire, L., Mortensen, J., Krisch, S., Achterberg, E.P., 2018. Non-linear response of summertime marine productivity to increased meltwater discharge around Greenland. Nature Communications 9, Article 3256.

Kiuru, P., Ojala, A., Mammarella, I., Heiskanen, J., Kämäräinen, M., Vesala, T., Huttula, T., 2018. Effects of climate change on CO2 concentration and efflux in a humic boreal lake: A modeling study. Journal of Geophysical Research: Biogeosciences 123, 2212-2233.

Leach, N.J., Millar, R.J., Haustein, K., Jenkins, S., Graham, E., Allen, M.R., 2018. Current level and rate of warming determine emissions budgets under ambitious mitigation. Nature Geoscience 11, 574-579.

Lindgren, A., Hugelius, G., Kuhry, P., 2018. Extensive loss of past permafrost carbon but a net accumulation into present-day soils. Nature 560, 219-222.

Walter Anthony, K., Schneider von Deimling, T., Nitze, I., Frolking, S., Emond, A., Daanen, R., Anthony, P., Lindgren, P., Jones, B., Grosse, G., 2018. 21st-century modeled permafrost carbon emissions accelerated by abrupt thaw beneath lakes. Nature Communications 9, Article 3262.

Coal/Lignite/Peat Geochemistry

Guo, B., Shao, L., Hilton, J., Wang, S., Zhang, L., 2018. Sequence stratigraphic interpretation of peatland evolution in thick coal seams: Examples from Yimin Formation (Early Cretaceous), Hailaer Basin, China. International Journal of Coal Geology 196, 211-231.


Pinto, J.S.S., Assis, L.M., Andrade, M.A., Lanças, F.M., 2018. Pressurized liquid extraction of Brazilian coal followed by the extracts characterization by gas chromatography coupled to mass spectrometry. Journal of Chromatographic Science 56, 761-769.

Qi, Y., Hann, W., Subagyono, D.J.N., Fei, Y., Marshall, M., Jackson, W.R., Patti, A.F., Chaffee, A.L., 2018. Characterisation of the products of low temperature pyrolysis of Victorian brown coal in a semi-continuous/flow through system. Fuel 234, 1422-1430.

Singh, A.K., Kumar, A., Hakimi, M.H., 2018. Organic geochemical and petrographical characteristics of the Nagaur lignites, Western Rajasthan, India and their relevance to liquid hydrocarbon generation. Arabian Journal of Geosciences 11, Article 406.

Wang, F., Dong, X., Fan, X., Zhao, Y.-P., Li, G.-S., Wang, C.-F., Wei, X.-Y., Ma, F.-Y., Zhong, M., 2018. In-source collision activated dissociation for coal/biomass-based model compounds and structural characterization of a coal extract. Fuel 234, 1033-1043.

COAL BED METHANE

Chen, R., Qin, Y., Zhang, P., Wang, Y., 2018. Changes in pore structure of coal caused by CS2 treatment and its methane adsorption response. Geofluids 2018, Article 7578967.

Chen, S., Tang, D., Tao, S., Chen, Z., Xu, H., Li, S., 2018. Coal reservoir heterogeneity in multicoal seams of the Panguan Syncline, western Guizhou, China: Implication for the development of superposed CBM-bearing systems. Energy & Fuels 32, 8241-8253.


Ghosh, S., Rodrigues, S., Varma, A.K., Esterle, J., Patra, S., Dirghangi, S.S., 2018. Petrographic and Raman spectroscopic characterization of coal from Himalayan fold-thrust belts of Sikkim, India. International Journal of Coal Geology 196, 246-259.

Hao, D., Zhang, L., Ye, Z., Tu, S., Zhang, C., 2018. Experimental study on the effects of the moisture content of bituminous coal on its gas seepage characteristics. Arabian Journal of Geosciences 11, Article 436.

Kumar, J., Mendhe, V.A., Kamble, A.D., Bannerjee, M., Mishra, S., Singh, B.D., Mishra, V.K., Singh, P.K., Singh, H., 2018. Coalbed methane reservoir characteristics of coal seams of south Karanpura coalfield, Jharkhand, India. International Journal of Coal Geology 196, 185-200.

Liu, Z., Liu, D., Cai, Y., Pan, Z., 2018. The impacts of flow velocity on permeability and porosity of coals by core flooding and nuclear magnetic resonance: Implications for coalbed methane production. Journal of Petroleum Science and Engineering 171, 938-950.

Lu, G., Wang, J., Wei, C., Song, Y., Yan, G., Zhang, J., Chen, G., 2018. Pore fractal model applicability and fractal characteristics of seepage and adsorption pores in middle rank tectonic deformed coals from the Huaibei coal field. Journal of Petroleum Science and Engineering 171, 808-817.

Meng, Y., Li, Z., 2018. Experimental comparisons of gas adsorption, sorption induced strain, diffusivity and permeability for low and high rank coals. Fuel 234, 914-923.

Qin, S., Zhang, Y., Zhao, C., Zhou, Z., 2018. Geochemical evidence for in situ accumulation of tight gas in the Xujiahe Formation coal measures in the central Sichuan Basin, China. International Journal of Coal Geology 196, 173-184.

Sharma, A., Jagarapu, A., Micale, C., Walia, D., Jackson, S., Dhurjati, P.S., 2018. Modeling framework for biogenic methane formation from coal. Energy & Fuels 32, 8453-8461.

Szafranek-Nakonieczna, A., Zheng, Y., Słowakiewicz, M., Pytlak, A., Polakowski, C., Kubaczyński, A., Bieganowski, A., Banach, A., Wolińska, A., Stępniewska, Z., 2018. Methanogenic potential of lignites in Poland. International Journal of Coal Geology 196, 201-210.

Xu, J., Zhai, C., Qin, L., Liu, S., 2018. Pulse hydraulic fracturing technology and its application in coalbed methane extraction. International Journal of Oil, Gas and Coal Technology 19, 115-133.


Cosmochemistry/Planetary Geochemistry

Auchettl, R., Ruzi, M., Appadoo, D.R.T., Robertson, E.G., Ennis, C., 2018. Binary-phase acetonitrile and water aerosols: Infrared studies and theoretical simulation at Titan atmosphere conditions. ACS Earth and Space Chemistry 2, 811-820.

Braukmüller, N., Wombacher, F., Hezel, D.C., Escoube, R., Münker, C., 2018. The chemical composition of carbonaceous chondrites: Implications for volatile element depletion, complementarity and alteration. Geochimica et Cosmochimica Acta 239, 17-48.

Dubois, D., Carrasco, N., Petrucciani, M., Vettier, L., Tigrine, S., Pernot, P., 2019. In situ investigation of neutrals involved in the formation of Titan tholins. Icarus 317, 182-196.

Guzman, M., McKay, C.P., Quinn, R.C., Szopa, C., Davila, A.F., Navarro-González, R., Freissinet, C., 2018. Identification of chlorobenzene in the Viking gas chromatograph-mass spectrometer data sets: Reanalysis of Viking Mission data consistent with aromatic organic compounds on Mars. Journal of Geophysical Research: Planets 123, 1674-1683.

Mahan, B., Moynier, F., Siebert, J., Gueguen, B., Agranier, A., Pringle, E.A., Bollard, J., Connelly, J.N., Bizzarro, M., 2018. Volatile element evolution of chondrules through time. Proceedings of the National Academy of Sciences 115, 8547-8552.

Royle, S.H., Oberlin, E., Watson, J.S., Montgomery, W., Kounaves, S.P., Sephton, M.A., 2018. Perchlorate-driven combustion of organic matter during pyrolysis-gas chromatography-mass spectrometry: Implications for organic matter detection on Earth and Mars. Journal of Geophysical Research: Planets 123, 1901-1909.

Srinivasan, P., Dunlap, D.R., Agee, C.B., Wadhwa, M., Coleff, D., Ziegler, K., Zeigler, R., McCubbin, F.M., 2018. Silica-rich volcanism in the early solar system dated at 4.565 Ga. Nature Communications 9, Article 3036.

Tartèse, R., Chaussidon, M., Gurenko, A., Delarue, F., Robert, F., 2018. Insights into the origin of carbonaceous chondrite organics from their triple oxygen isotope composition. Proceedings of the National Academy of Sciences 115, 8535-8540.

Tsuno, K., Grewal, D.S., Dasgupta, R., 2018. Core-mantle fractionation of carbon in Earth and Mars: The effects of sulfur. Geochimica et Cosmochimica Acta 238, 477-495.

ASTROBIOLOGY

Moreno-Paz, M., Gómez-Cifuentes, A., Ruiz-Bermejo, M., Hofstetter, O., Maquieira, Á., Manchado, J.M., Morais, S., Sephton, M.A., Niessner, R., Knopp, D., Parro, V., 2018. Detecting nonvolatile life- and nonlife-derived organics in a carbonaceous chondrite analogue with a new multiplex immunoassay and its relevance for planetary exploration. Astrobiology 18, 1041-1056.

Pontefract, A., Hachey, J., Zuber, M.T., Ruvkun, G., Carr, C.E., 2018. Sequencing nothing: Exploring failure modes of nanopore sensing and implications for life detection. Life Sciences in Space Research 18, 80-86.

Schulze-Makuch, D., Crawford, I.A., 2018. Was there an early habitability window for Earth's Moon? Astrobiology 18, 985-988.

Environmental Geochemistry

Adams, J.K., Martins, C.C., Rose, N.L., Shchetnikov, A.A., Mackay, A.W., 2018. Lake sediment records of persistent organic pollutants and polycyclic aromatic hydrocarbons in southern Siberia mirror the changing fortunes of the Russian economy over the past 70 years. Environmental Pollution 242, 528-538.


Burdon, D., Barnard, S., Boyes, S.J., Elliott, M., 2018. Oil and gas infrastructure decommissioning in marine protected areas: System complexity, analysis and challenges. Marine Pollution Bulletin 135, 739-758.

dos Santos Rodrigues, C.C., Santos, L.G.G.V., Santos, E., Damasceno, F.C., Corrêa, J.A.M., 2018. Polycyclic aromatic hydrocarbons in sediments of the Amazon River Estuary (Amapá, Northern Brazil): Distribution, sources and potential ecological risk. Marine Pollution Bulletin 135, 769-775.

Elfadly, A.A.A., El Nady, M.M., Ahmed, O.E., 2018. Effect provenance of organic matters in surface sediments from coastal stations in the Gulf of Suez Gulf, Egypt: An implication from occurrence of triterpanes and steranes fragmentgrams. Petroleum Science and Technology 36, 1286-1291.

Käppler, A., Fischer, M., Scholz-Böttcher, B.M., Oberbeckmann, S., Labrenz, M., Fischer, D., Eichhorn, K.-J., Voit, B., 2018. Comparison of μ-ATR-FTIR spectroscopy and py-GCMS as identification tools for microplastic particles and fibers isolated from river sediments. Analytical and Bioanalytical Chemistry 410, 5313-5327.

Mandić, J., Tronczyński, J., Kušpilić, G., 2018. Polycyclic aromatic hydrocarbons in surface sediments of the mid-Adriatic and along the Croatian coast: Levels, distributions and sources. Environmental Pollution 242, 519-527.

Nádudvari, Á., Marynowski, L., Fabiańska, M.J., 2018. Application of organic environmental markers in the assessment of recent and fossil organic matter input in coal wastes and river sediments: A case study from the Upper Silesia Coal Basin (Poland). International Journal of Coal Geology 196, 302-316.

Netzer, R., Henry, I.A., Ribicic, D., Wibberg, D., Brönner, U., Brakstad, O.G., 2018. Petroleum hydrocarbon and microbial community structure successions in marine oil-related aggregates associated with diatoms relevant for Arctic conditions. Marine Pollution Bulletin 135, 759-768.

Peischl, J., Eilerman, S.J., Neuman, J.A., Aikin, K.C., Gouw, J., Gilman, J.B., Herndon, S.C., Nadkarni, R., Trainer, M., Warneke, C., Ryerson, T.B., 2018. Quantifying methane and ethane emissions to the atmosphere from central and western U.S. oil and natural gas production regions. Journal of Geophysical Research: Atmospheres 123, 7725-7740.


Sun, T., Levin, B.D.A., Schmidt, M.P., Guzman, J.J.L., Enders, A., Martínez, C.E., Muller, D.A., Angenent, L.T., Lehmann, J., 2018. Simultaneous quantification of electron transfer by carbon matrices and functional groups in pyrogenic carbon. Environmental Science & Technology 52, 8538-8547.


Vagge, G., Cutroneo, L., Castellano, M., Canepa, G., Bertolotto, R.M., Capello, M., 2018. The effects of dredging and environmental conditions on concentrations of polycyclic aromatic hydrocarbons in the water column. Marine Pollution Bulletin 135, 704-713.

BIOREMEDIATION


Gałązka, A., Grządziel, J., Gałązka, R., Ukalska-Jaruga, A., Strzelecka, J., Smreczak, B., 2018. Genetic and functional diversity of bacterial microbiome in soils with long term impacts of petroleum hydrocarbons. Frontiers in Microbiology 9, 1923. doi: 1910.3389/fmicb.2018.01923.

Karlapudi, A.P., Venkateswarulu, T.C., Tammineedi, J., Kanumuri, L., Ravuru, B.K., Dirisala, V.r., Kodali, V.P., 2018. Role of biosurfactants in bioremediation of oil pollution-a review. Petroleum 4, 241-249.

Lumactud, R., Fulthorpe, R.R., 2018. Endophytic bacterial community structure and function of herbaceous plants from petroleum hydrocarbon contaminated and non-contaminated sites. Frontiers in Microbiology 9, 1926. doi: 1910.3389/fmicb.2018.01926.

Medjor, W.O., Akpoveta, V.O., Egharevba, F., 2018. Kinetics and physicochemical studies of surfactant enhanced remediation of hydrocarbons contaminated groundwater. Egyptian Journal of Petroleum 27, 169-176.

Moe, W.M., Reynolds, S.J., Griffin, M.A., McReynolds, J.B., 2018. Bioremediation strategies aimed at stimulating chlorinated solvent dehalogenation can lead to microbially-mediated toluene biogenesis. Environmental Science & Technology 52, 9311-9319.


Rosell, M., Palau, J., Mortan, S.H., Caminal, G., Soler, A., Shouakar-Stash, O., Marco-Urrea, E., 2019. Dual carbon - chlorine isotope fractionation during dichloroelimination of

1,1,2-trichloroethane by an enrichment culture containing Dehalogenimonas sp.. Science of The Total Environment 648, 422-429.

Wu, Y., Jing, X., Gao, C., Huang, Q., Cai, P., 2018. Recent advances in microbial electrochemical system for soil bioremediation. Chemosphere 211, 156-163.

OIL SPILLS/DEEPWATER HORIZON/MACONDO


Philibert, D.A., Lyons, D., Philibert, C., Tierney, K.B., 2019. Field-collected crude oil, weathered oil and dispersants differentially affect the early life stages of freshwater and saltwater fishes. Science of The Total Environment 647, 1148-1157.


Nissanka, I.D., Yapa, P.D., 2018. Calculation of oil droplet size distribution in ocean oil spills: A review. Marine Pollution Bulletin 135, 723-734.

Yu, X., Zhang, W., Liu, X., Lei, J., Lin, Z., Yao, Z., Yao, X., Jin, X., Yang, H., Huang, H., 2018. The distribution of and biodegradation impact on spilled oil in sediments from Dalian Bay, NE China. Marine Pollution Bulletin 135, 1007-1015.

OIL SAND PROCESS WATERS/TAILING PONDS

Fang, Z., Chelme-Ayala, P., Shi, Q., Xu, C., Gamal El-Din, M., 2018. Degradation of naphthenic acid model compounds in aqueous solution by UV activated persulfate: Influencing factors, kinetics and reaction mechanisms. Chemosphere 211, 271-277.

White, K.B., Liber, K., 2018. Early chemical and toxicological risk characterization of inorganic constituents in surface water from the Canadian oil sands first large-scale end pit lake. Chemosphere 211, 745-757.

Willis, C.E., St. Louis, V.L., Kirk, J.L., St. Pierre, K.A., Dodge, C., 2019. Tailings ponds of the Athabasca Oil Sands Region, Alberta, Canada, are likely not significant sources of total mercury and methylmercury to nearby ground and surface waters. Science of The Total Environment 647, 1604-1610.

UNCONVENTIONALSHALE GAS-CBM RESOURCES

Cai, Z., Wen, H., Li, L., 2018. Clay distribution patterns regulate natural attenuation of Marcellus Shale waters in natural aquifers. Energy & Fuels.

Casey, J.A., Wilcox, H.C., Hirsch, A.G., Pollak, J., Schwartz, B.S., 2018. Associations of unconventional natural gas development with depression symptoms and disordered sleep in Pennsylvania. Scientific Reports 8, Article 11375.

Chen See, J.R., Ulrich, N., Nwanosike, H., McLimans, C.J., Tokarev, V., Wright, J.R., Campa, M.F., Grant, C.J., Hazen, T.C., Niles, J.M., Ressler, D., Lamendella, R., 2018. Bacterial biomarkers of Marcellus Shale activity in Pennsylvania. Frontiers in Microbiology 9, 1697. doi: 1610.3389/fmicb.2018.01697.

Englander, J.G., Brandt, A.R., Conley, S., Lyon, D.R., Jackson, R.B., 2018. Aerial interyear comparison and quantification of methane emissions persistence in the Bakken Formation of North Dakota, USA. Environmental Science & Technology 52, 8947-8953.

Huang, K.Z., Tang, H.L., Xie, Y.F., 2018. Impacts of shale gas production wastewater on disinfection byproduct formation: An investigation from a non-bromide perspective. Water Research 144, 656-664.

Huang, K.Z., Xie, Y.F., Tang, H.L., 2019. Formation of disinfection by-products under influence of shale gas produced water. Science of The Total Environment 647, 744-751.

Johann, L., Shapiro, S.A., Dinske, C., 2018. The surge of earthquakes in Central Oklahoma has features of reservoir-induced seismicity. Scientific Reports 8, Article 11505.

Evolution/Paleontology/Palynology

Britt, B.B., Dalla Vecchia, F.M., Chure, D.J., Engelmann, G.F., Whiting, M.F., Scheetz, R.D., 2018. Caelestiventus hanseni gen. et sp. nov. extends the desert-dwelling pterosaur record back 65 million years. Nature Ecology & Evolution 2, 1386-1392.

Darroch, S.A.F., Smith, E.F., Laflamme, M., Erwin, D.H., 2018. Ediacaran extinction and Cambrian explosion. Trends in Ecology & Evolution 33, 653-663.

Fiorillo, A.R., McCarthy, P.J., Kobayashi, Y., Tomsich, C.S., Tykoski, R.S., Lee, Y.-N., Tanaka, T., Noto, C.R., 2018. An unusual association of hadrosaur and therizinosaur tracks within Late Cretaceous rocks of Denali National Park, Alaska. Scientific Reports 8, Article 11706.

Gill, F.L., Hummel, J., Sharifi, A.R., Lee, A.P., Lomax, B.H., 2018. Diets of giants: the nutritional value of sauropod diet during the Mesozoic. Palaeontology 61, 647-658.

Giordano, M., Olivieri, C., Ratti, S., Norici, A., Raven, J.A., Knoll, A.H., 2018. A tale of two eras: Phytoplankton composition influenced by oceanic paleochemistry. Geobiology 16, 498-506.


Kolesnikov, A.V., Rogov, V.I., Bykova, N.V., Danelian, T., Clausen, S., Maslov, A.V., Grazhdankin, D.V., 2018. The oldest skeletal macroscopic organism Palaeopascichnus linearis. Precambrian Research 316, 24-37.

Nielsen, C., Brunet, T., Arendt, D., 2018. Evolution of the bilaterian mouth and anus. Nature Ecology & Evolution 2, 1358-1376.

Picciani, N., Kerlin, J.R., Sierra, N., Swafford, A.J.M., Ramirez, M.D., Roberts, N.G., Cannon, J.T., Daly, M., Oakley, T.H., 2018. Prolific origination of eyes in cnidaria with co-option of non-visual opsins. Current Biology 28, 2413-2419.

Qi, C., Li, C., Gabbott, S.E., Ma, X., Xie, L., Deng, W., Jin, C., Hou, X.-G., 2018. Influence of redox conditions on animal distribution and soft-bodied fossil preservation of the Lower Cambrian Chengjiang biota. Palaeogeography, Palaeoclimatology, Palaeoecology 507, 180-187.

ORIGINS OF LIFE/MICROBIAL GENOMICS

Carter Jr., C.W., Wills, P.R., 2018. Hierarchical groove discrimination by Class I and II aminoacyl-tRNA synthetases reveals a palimpsest of the operational RNA code in the tRNA acceptor-stem bases. Nucleic Acids Research, gky600-gky600.


Fornaro, T., Brucato, J.R., Feuillie, C., Sverjensky, D.A., Hazen, R.M., Brunetto, R., D'Amore, M., Barone, V., 2018. Binding of nucleic acid components to the serpentinite-hosted hydrothermal mineral brucite. Astrobiology 18, 989-1007.

Fournier, G.P., Poole, A.M., 2018. A briefly argued case that Asgard archaea are part of the eukaryote tree. Frontiers in Microbiology 9, 1896. doi: 1810.3389/fmicb.2018.01896.

Grégoire, B., Greenwell, H.C., Fraser, D.G., 2018. Peptide formation on layered mineral surfaces: The key role of brucite-like minerals on the enhanced formation of alanine dipeptides. ACS Earth and Space Chemistry 2, 852-862.

Jiang, W., Pacella, M.S., Vali, H., Gray, J.J., McKee, M.D., 2018. Chiral switching in biomineral suprastructures induced by homochiral L-amino acid. Science Advances 4, Article eaas9819.

Lancet, D., Zidovetzki, R., Markovitch, O., 2018. Systems protobiology: origin of life in lipid catalytic networks. Journal of The Royal Society Interface 15, Article 20180159.

Louca, S., Shih, P.M., Pennell, M.W., Fischer, W.W., Parfrey, L.W., Doebeli, M., 2018. Bacterial diversification through geological time. Nature Ecology & Evolution 2, 1458-1467.

Ranjan, S., Todd, Z.R., Sutherland, J.D., Sasselov, D.D., 2018. Sulfidic anion concentrations on early Earth for surficial origins-of-life chemistry. Astrobiology 18, 1023-1040.

Rimmer, P.B., Xu, J., Thompson, S.J., Gillen, E., Sutherland, J.D., Queloz, D., 2018. The origin of RNA precursors on exoplanets. Science Advances 4, Article eaar3302.

Smith, G.P., Fraccia, T.P., Todisco, M., Zanchetta, G., Zhu, C., Hayden, E., Bellini, T., Clark, N.A., 2018. Backbone-free duplex-stacked monomer nucleic acids exhibiting Watson–Crick selectivity. Proceedings of the National Academy of Sciences 115, E7658-E7664.

HOMINID EVOLUTION

Fernández, P.J., Mongle, C.S., Leakey, L., Proctor, D.J., Orr, C.M., Patel, B.A., Almécija, S., Tocheri, M.W., Jungers, W.L., 2018. Evolution and function of the hominin forefoot. Proceedings of the National Academy of Sciences 115, 8746-8751.

O’Connell, J.F., Allen, J., Williams, M.A.J., Williams, A.N., Turney, C.S.M., Spooner, N.A., Kamminga, J., Brown, G., Cooper, A., 2018. When did Homo sapiens first reach Southeast Asia and Sahul? Proceedings of the National Academy of Sciences 115, 8482-8490.

Vogel, G., 2018. Ancient DNA reveals tryst between extinct human species. Science 361, 737.

Fluid Inclusions

Clarke, H., Turner, P., Bustin, R.M., Riley, N., Besly, B., 2018. Shale gas resources of the Bowland Basin, NW England: a holistic study. Petroleum Geoscience 24, 287-322.

Huang, Y., Tarantola, A., Wang, W., Caumon, M.-C., Pironon, J., Lu, W., Yan, D., Zhuang, X., 2018. Charge history of CO2 in Lishui sag, East China Sea basin: Evidence from quantitative Raman analysis of CO2-bearing fluid inclusions. Marine and Petroleum Geology 98, 50-65.

Pestilho, A.L.S., Monteiro, L.V.S., Carbonezi, C.A., Jorge, S.B., Santos Neto, E.V., 2018. Linking the geochemistry of crude oils and petroleum inclusions in the Ubarana and Lorena oilfields, Potiguar Basin, Brazilian Equatorial Margin. Organic Geochemistry 124, 133-150.

Zhao, L., Cai, C., Jin, R., Li, J., Li, H., Wei, J., Guo, H., Zhang, B., 2018. Mineralogical and geochemical evidence for biogenic and petroleum-related uranium mineralization in the Qianjiadian deposit, NE China. Ore Geology Reviews 101, 273-292.

General Interest

Hu, A., Guo, J.-J., Pan, H., Zuo, Z., 2018. Selective functionalization of methane, ethane, and higher alkanes by cerium photocatalysis. Science 361, 668-672.

Uusitalo, J., Arppe, L., Hackman, T., Helama, S., Kovaltsov, G., Mielikäinen, K., Mäkinen, H., Nöjd, P., Palonen, V., Usoskin, I., Oinonen, M., 2018. Solar superstorm of AD 774 recorded subannually by Arctic tree rings. Nature Communications 9, Article 3495.

Geology

Bodin, S., Rose, J.C., 2018. Hydrocarbon-seep carbonates associated with Mesozoic environmental perturbations: Example from the Lower Bajocian of Morocco. Sedimentary Geology 374, 53-68.

Butt, A.J., Gould, K., 2018. 3D source-rock modelling in frontier basins: a case study from the Zambezi Delta Depression. Petroleum Geoscience 24, 277-286.

Cheng, Q., 2018. Extrapolations of secular trends in magmatic intensity and mantle cooling: Implications for future evolution of plate tectonics. Gondwana Research 63, 268-273.

Davies, H.S., Green, J.A.M., Duarte, J.C., 2018. Back to the future: Testing different scenarios for the next supercontinent gathering. Global and Planetary Change 169, 133-144.

Müller, R.D., Cannon, J., Qin, X., Watson, R.J., Gurnis, M., Williams, S., Pfaffelmoser, T., Seton, M., Russell, S.H.J., Zahirovic, S., 2018. GPlates: Building a virtual Earth through deep time. Geochemistry, Geophysics, Geosystems 19, 2243-2261.

Qu, H., Zhou, Z., Zhang, YunFeng, Chen, W., Zhang, Z., Luo, X., Ma, C., Tan, F., Zhu, Y., 2018. Research progress of porosity in microbial carbonates. Acta Sedimentologica Sinica 86, 651-663.

Xu, Y., Sommerdijk, N.A.J.M., 2018. Aragonite formation in confinements: A step toward understanding polymorph control. Proceedings of the National Academy of Sciences 115, 8469-8471.


BOLIDE IMPACTS/CRATER GEOCHEMISTRY

Schmieder, M., Shaulis, B.J., Lapen, T.J., Kring, D.A., 2018. U–Th–Pb systematics in zircon and apatite from the Chicxulub impact crater, Yucatán, Mexico. Geological Magazine 155, 1330-1350.

Stephant, A., Garvie, L.A.J., Mane, P., Hervig, R., Wadhwa, M., 2018. Terrestrial exposure of a fresh Martian meteorite causes rapid changes in hydrogen isotopes and water concentrations. Scientific Reports 8, Article 12385.

Hydrates


Khatami, M.S., Shahsavand, A., 2018. Application of population balance theory for dynamic modeling of methane and ethane hydrate formation processes. Energy & Fuels 32, 8131-8144.

Li, G., Li, C., Li, X., Wei, N., 2018. Permeability experiments on the methane hydrate in quartz sands and its model verification. Natural Gas Industry B 5, 298-305.

Liu, H., Guo, P., Zhan, S., Ma, P., Wei, N., Zhao, J., Qiu, Y., 2018. Experimental investigation into formation/dissociation characteristics of methane hydrate in consolidated sediments with resistance measurement. Fuel 234, 985-995.

Mu, L., von Solms, N., 2018. Experimental study on methane production from hydrate-bearing sandstone by flue gas swapping. Energy & Fuels 32, 8167-8174.

Nole, M., Daigle, H., Cook, A.E., Malinverno, A., Flemings, P.B., 2018. Burial-driven methane recycling in marine gas hydrate systems. Earth and Planetary Science Letters 499, 197-204.

Sirino, T.H., Marcelino Neto, M.A., Bertoldi, D., Morales, R.E.M., Sum, A.K., 2018. Multiphase flash calculations for gas hydrates systems. Fluid Phase Equilibria 475, 45-63.

Wang, G., Zhong, L., Zhou, S., Liu, Q., Li, Q., Fu, Q., Wang, L., Huang, R., Wang, G., Li, X., 2018. Jet breaking tools for natural gas hydrate exploitation and their support technologies. Natural Gas Industry B 5, 312-318.

Wei, N., Xu, H., Sun, W., Zhao, J., Zhang, L., Fu, Q., Pang, W., Zheng, L., Lü, X., 2018. Migration laws of natural gas hydrate solid particles with different abundance in horizontal wells. Natural Gas Industry B 5, 306-311.

Zhao, J., Ji, Y., Wu, Y., 2018. Reliability experiment on the calculation of natural gas hydrate saturation using acoustic wave data. Natural Gas Industry B 5, 293-297.

Isotope Geochemistry

Brown, S.T., Basu, A., Ding, X., Christensen, J.N., DePaolo, D.J., 2018. Uranium isotope fractionation by abiotic reductive precipitation. Proceedings of the National Academy of Sciences 115, 8688-8693.



Dellinger, M., West, A.J., Paris, G., Adkins, J.F., Pogge von Strandmann, P.A.E., Ullmann, C.V., Eagle, R.A., Freitas, P., Bagard, M.-L., Ries, J.B., Corsetti, F.A., Perez-Huerta, A., Kampf, A.R., 2018. The Li isotope composition of marine biogenic carbonates: Patterns and mechanisms. Geochimica et Cosmochimica Acta 236, 315-335.


Duan, Y., Wu, Y., Zhao, Y., Cao, X., Ma, L., 2018. Hydrogen isotopic characteristic of hydrocarbon gas pyrolyzed by herbaceous swamp peat in hydrous and anhydrous thermal simulation experiments. Journal of Natural Gas Geoscience 3, 67-72.

Frei, R., Paulukat, C., Bruggmann, S., Klaebe, R.M., 2018. A systematic look at chromium isotopes in modern shells – implications for paleo-environmental reconstructions. Biogeosciences 15, 4905-4922.

González Arismendi, G., Tappert, R., McKellar, R.C., Wolfe, A.P., Muehlenbachs, K., 2018. Deuterium exchangeability in modern and fossil plant resins. Geochimica et Cosmochimica Acta 239, 159-172.

Han, W., Ma, W., Tao, S., Huang, S., Hou, L., Yao, J., 2018. Carbon isotope reversal and its relationship with natural gas origins in the Jingbian gas field, Ordos Basin, China. International Journal of Coal Geology 196, 260-273.

Heinzelmann, S.M., Villanueva, L., Lipsewers, Y.A., Sinke-Schoen, D., Sinninghe Damsté, J.S., Schouten, S., van der Meer, M.T.J., 2018. Assessing the metabolism of sedimentary microbial communities using the hydrogen isotopic composition of fatty acids. Organic Geochemistry 124, 123-132.

Hermoso, M., Lecasble, M., 2018. The effect of salinity on the biogeochemistry of the coccolithophores with implications for coccolith-based isotopic proxies. Biogeosciences DIscussions 2018.

Lin, M., Zhang, X., Li, M., Xu, Y., Zhang, Z., Tao, J., Su, B., Liu, L., Shen, Y., Thiemens, M.H., 2018. Five-S-isotope evidence of two distinct mass-independent sulfur isotope effects and implications for the modern and Archean atmospheres. Proceedings of the National Academy of Sciences 115, 8541-8546.

Maeda, A., Fujita, K., Horikawa, K., Suzuki, A., Ohno, Y., Kawahata, H., 2018. Calibration between temperature and Mg/Ca and oxygen isotope ratios in high-magnesium calcite tests of asexually reproduced juveniles of large benthic foraminifers. Marine Micropaleontology 143, 63-69.

Masterson, A., Alperin, M.J., Berelson, W.M., Johnston, D.T., 2018. Interpreting multiple sulfur isotope signals in modern anoxic sediments using a full diagenetic model (California-Mexico margin: Alfonso Basin). American Journal of Science 318, 459-490.

Owen, R., Day, C.C., Henderson, G.M., 2018. CaveCalc: A new model for speleothem chemistry & isotopes. Computers & Geosciences 119, 115-122.

Roberts, J., Kaczmarek, K., Langer, G., Skinner, L.C., Bijma, J., Bradbury, H., Turchyn, A.V., Lamy, F., Misra, S., 2018. Lithium isotopic composition of benthic foraminifera: A new proxy for paleo-pH reconstruction. Geochimica et Cosmochimica Acta 236, 336-350.

Rosell, M., Palau, J., Mortan, S.H., Caminal, G., Soler, A., Shouakar-Stash, O., Marco-Urrea, E., 2019. Dual carbon - chlorine isotope fractionation during dichloroelimination of 1,1,2-trichloroethane by an enrichment culture containing Dehalogenimonas sp.. Science of The Total Environment 648, 422-429.

Schäfer, I.K., Bliedtner, M., Wolf, D., Kolb, T., Zech, J., Faust, D., Zech, R., 2018. A δ13C and δ2H leaf wax record from the Late Quaternary loess-paleosoil sequence El Paraíso, Central Spain. Palaeogeography, Palaeoclimatology, Palaeoecology 507, 52-59.


Wunderlich, A., Heipieper, H.J., Elsner, M., Einsiedl, F., 2018. Solvent stress-induced changes in membrane fatty acid composition of denitrifying bacteria reduce the extent of nitrogen stable isotope fractionation during denitrification. Geochimica et Cosmochimica Acta 239, 275-283.

Zhao, B., Zhang, Y., Huang, X., Qiu, R., Zhang, Z., Meyers, P.A., 2018. Comparison of n-alkane molecular, carbon and hydrogen isotope compositions of different types of plants in the Dajiuhu peatland, central China. Organic Geochemistry 124, 1-11.

CLUMPED ISOTOPES

Breitenbach, S.F.M., Mleneck-Vautravers, M.J., Grauel, A.-L., Lo, L., Bernasconi, S.M., Müller, I.A., Rolfe, J., Gázquez, F., Greaves, M., Hodell, D.A., 2018. Coupled Mg/Ca and clumped isotope analyses of foraminifera provide consistent water temperatures. Geochimica et Cosmochimica Acta 236, 283-296.

Kluge, T., John, C.M., Boch, R., Kele, S., 2018. Assessment of factors controlling clumped isotopes and δ18O values of hydrothermal vent calcites. Geochemistry, Geophysics, Geosystems 19, 1844-1858.

Peral, M., Daëron, M., Blamart, D., Bassinot, F., Dewilde, F., Smialkowski, N., Isguder, G., Bonnin, J., Jorissen, F., Kissel, C., Michel, E., Vázquez Riveiros, N., Waelbroeck, C., 2018. Updated calibration of the clumped isotope thermometer in planktonic and benthic foraminifera. Geochimica et Cosmochimica Acta 239, 1-16.

METHODS/INSTRUMENTATION

Mathematical Geochemistry/Phase Behavior


Microbiology/Extremophiles

Ghuneim, L.-A.J., Jones, D.L., Golyshin, P.N., Golyshina, O.V., 2018. Nano-sized and filterable bacteria and archaea: Biodiversity and function. Frontiers in Microbiology 9, 1971. doi: 1910.3389/fmicb.2018.01971.

Kim, J.-Y., Kim, D.-U., Kang, M.-S., Jang, J.H., Kim, S.J., Kim, M.J., Lee, J.Y., Lee, Y.S., Zhang, J., Lim, S., Kim, M.K., 2018. Roseomonas radiodurans sp. nov., a gamma-radiation-resistant bacterium isolated from gamma ray-irradiated soil. International Journal of Systematic and Evolutionary Microbiology 68, 2443-2447.


Zhou, Z., Pan, J., Wang, F., Gu, J.-D., Li, M., 2018. Bathyarchaeota: globally distributed metabolic generalists in anoxic environments. FEMS Microbiology Reviews 42, 639-655.

MICROBIAL ECOSYSTEMS


Cousins, C.R., Fogel, M., Bowden, R., Crawford, I., Boyce, A., Cockell, C., Gunn, M., 2018. Biogeochemical probing of microbial communities in a basalt-hosted hot spring at Kverkfjöll volcano, Iceland. Geobiology 16, 507-521.

Feeser, K.L., Van Horn, D.J., Buelow, H.N., Colman, D.R., McHugh, T.A., Okie, J.G., Schwartz, E., Takacs-Vesbach, C.D., 2018. Local and regional scale heterogeneity drive bacterial community diversity and composition in a polar desert. Frontiers in Microbiology 9, 1928. doi: 1910.3389/fmicb.2018.01928.

Fillol-Salom, A., Martínez-Rubio, R., Abdulrahman, R.F., Chen, J., Davies, R., Penadés, J.R., 2018. Phage-inducible chromosomal islands are ubiquitous within the bacterial universe. The ISME Journal 12, 2114-2128.

Jia, X., Dini-Andreote, F., Falcão Salles, J., 2018. Community assembly processes of the microbial rare biosphere. Trends in Microbiology 26, 738-747.

Kan, J., 2018. Storm events restructured bacterial community and their biogeochemical potentials. Journal of Geophysical Research: Biogeosciences 123, 2257-2269.

Kujala, K., Mikkonen, A., Saravesi, K., Ronkanen, A.-K., Tiirola, M., 2018. Microbial diversity along a gradient in peatlands treating mining-affected waters. FEMS Microbiology Ecology 94, Article fiy145.

López, D., Sepúlveda-Mardones, M., Ruiz-Tagle, N., Sossa, K., Uggetti, E., Vidal, G., 2019. Potential methane production and molecular characterization of bacterial and archaeal communities in a horizontal subsurface flow constructed wetland under cold and warm seasons. Science of The Total Environment 648, 1042-1051.


Müller, O., Seuthe, L., Bratbak, G., Paulsen, M.L., 2018. Bacterial response to permafrost derived organic matter input in an Arctic fjord. Frontiers in Marine Science 5, 263. doi: 210.3389/fmars.2018.00263.

Nascimento, F.J.A., Lallias, D., Bik, H.M., Creer, S., 2018. Sample size effects on the assessment of eukaryotic diversity and community structure in aquatic sediments using high-throughput sequencing. Scientific Reports 8, Article 11737.

Nawaz, A., Purahong, W., Lehmann, R., Herrmann, M., Totsche, K.U., Küsel, K., Wubet, T., Buscot, F., 2018. First insights into the living groundwater mycobiome of the terrestrial biogeosphere. Water Research 145, 50-61.

Pala, C., Molari, M., Nizzoli, D., Bartoli, M., Viaroli, P., Manini, E., 2018. Environmental drivers controlling bacterial and archaeal abundance in the sediments of a Mediterranean lagoon ecosystem. Current Microbiology 75, 1147-1155.

Ronholm, J., Goordial, J., Sapers, H.M., Izawa, M.R.M., Applin, D.M., Pontefract, A., Omelon, C.R., Lamarche-Gagnon, G., Cloutis, E.A., Whyte, L.G., 2018. Characterization of microbial communities hosted in quartzofeldspathic and serpentinite lithologies in Jeffrey Mine, Canada. Astrobiology 18, 1008-1022.


Tucker, Y.T., Mroz, T., 2018. Microbes in Marcellus Shale: Extremophiles living more than two kilometers inside the Earth? Fuel 234, 1205-1211.

Valdespino-Castillo, P.M., Cerqueda-García, D., Espinosa, A.C., Batista, S., Merino-Ibarra, M., Taş, N., Alcántara-Hernández, R.J., Falcón, L.I., 2018. Microbial distribution and turnover in Antarctic microbial mats highlight the relevance of heterotrophic bacteria in low-nutrient environments. FEMS Microbiology Ecology 94, Article fiy129.

Xue, P.-P., Carrillo, Y., Pino, V., Minasny, B., McBratney, A.B., 2018. Soil properties drive microbial community structure in a large scale transect in South Eastern Australia. Scientific Reports 8, Article 11725.

PETROLEUM DEGRADERS



Netzer, R., Henry, I.A., Ribicic, D., Wibberg, D., Brönner, U., Brakstad, O.G., 2018. Petroleum hydrocarbon and microbial community structure successions in marine oil-

related aggregates associated with diatoms relevant for Arctic conditions. Marine Pollution Bulletin 135, 759-768.


Oil & Gas Exploration

Cruz Luque, M.M., Urban-Rascon, E., Aguilera, R.F., Aguilera, R., 2018. Mexican unconventional plays: Geoscience, endowment, and economic considerations. SPE-189438-PA SPE Reservoir Evaluation & Engineering 21, 533-549.

Davidson, L.M., Arthur, T.J., Smith, G.F., Tubb, S., 2018. Geology and hydrocarbon potential of offshore SE Somalia. Petroleum Geoscience 24, 247-257.

Leila, M., Moscariello, A., 2018. Depositional and petrophysical controls on the volumes of hydrocarbons trapped in the Messinian reservoirs, onshore Nile Delta, Egypt. Petroleum 4, 250-267.

Ratnayake, A.S., Kularathne, C.W., Sampei, Y., 2018. Assessment of hydrocarbon generation potential and thermal maturity of the offshore Mannar Basin, Sri Lanka. Journal of Petroleum Exploration and Production Technology 8, 641-654.

Surjono, S.S., Hidayat, R., Wagimin, N., 2018. Triassic petroleum system as an alternative exploration concept in offshore western Timor Indonesia. Journal of Petroleum Exploration and Production Technology 8, 703-711.

Oil & Gas Generation/Expulsion


Marques, J.M., Etiope, G., Neves, M.O., Carreira, P.M., Rocha, C., Vance, S.D., Christensen, L., Miller, A.Z., Suzuki, S., 2018. Linking serpentinization, hyperalkaline mineral waters and abiotic methane production in continental peridotites: an integrated hydrogeological-bio-geochemical model from the Cabeço de Vide CH4-rich aquifer (Portugal). Applied Geochemistry 96, 287-301.

Varma, A.K., Biswas, S., Patil, D.J., Mani, D., Misra, S., Hazra, B., 2019. Significance of lithotypes for hydrocarbon generation and storage. Fuel 235, 396-405.

Wood, D.A., Hazra, B., 2018. Pyrolysis S2-peak characteristics of Raniganj shales (India) reflect complex combinations of kerogen kinetics and other processes related to different levels of thermal maturity. Advances in Geo-Energy Research 2, 343-368.

Wu, Y., Zhang, Z., Sun, L., Li, Y., Su, L., Li, X., Xu, H., Tu, Y., 2018. The effect of pressure and hydrocarbon expulsion on hydrocarbon generation during pyrolyzing of continental type-III kerogen source rocks. Journal of Petroleum Science and Engineering 170, 958-966.

Zhao, Z., Pang, X., Jiang, F., Wang, K., Li, L., Zhang, K., Zheng, X., 2018. Hydrocarbon generation from confined pyrolysis of lower Permian Shanxi Formation coal and coal measure mudstone in the Shenfu area, northeastern Ordos Basin, China. Marine and Petroleum Geology 97, 355-369.

Oil & Gas Geochemistry

Asahina, K., Suzuki, N., 2018. Methylated naphthalenes as indicators for evaluating the source and source rock lithology of degraded oils. Organic Geochemistry 124, 46-62.

Bao, J., Wang, Z., Zhu, C., Wang, L., Chen, Y., Zhou, F., 2018. A new kind of crude oils and the geochemical characteristics in the Dongping area, Qaidam Basin. Acta Sedimentologica Sinica 86, 829-841.

Chen, X., Hao, F., Guo, L., Yin, J., Cao, Y., Zou, H., 2018. Characteristic of source rocks and origin of crude oils in the Raoyang Sag and Baxian Sag, Bohai Bay Basin, China: Insights from geochemical and geological analyses. Marine and Petroleum Geology 97, 407-421.

Cheng, B., Chen, Z., Chen, T., Yang, C., Wang, T.G., 2018. Biomarker signatures of the Ediacaran–Early Cambrian origin petroleum from the central Sichuan Basin, South China: Implications for source rock characteristics. Marine and Petroleum Geology 96, 577-590.

El-Sabagh, S.M., El-Naggar, A.Y., El Nady, M.M., Badr, I.A., Ebiad, M.A., Abdullah, E.S., 2018. Fingerprinting of biomarker characteristics of some Egyptian crude oils in Northern Western Desert as evidence for organic matter input and maturity level assessment. Egyptian Journal of Petroleum 27, 201-208.

El Nady, M.M., Ramadan, F.S., Hammad, M.M., Mousa, D.A., Lotfy, N.M., 2018. Oil: Source rock correlations of Al Baraka oil field, Komombo basin, South Egypt: An implication from biomarkers characteristics. Petroleum Science and Technology 36, 1250-1257.


Ge, X., Shen, C., Selby, D., Wang, G., Yang, Z., Gong, Y., Xiong, S., 2018. Neoproterozoic–Cambrian petroleum system evolution of the Micang Shan uplift, northern Sichuan Basin, China: Insights from pyrobitumen rhenium–osmium geochronology and apatite fission-track analysis. American Association of Petroleum Geologists Bulletin 102, 1429-1453.




Liu, J., Selby, D., Obermajer, M., Mort, A., 2018. Rhenium–osmium geochronology and oil–source correlation of the Duvernay petroleum system, Western Canada sedimentary basin: Implications for the application of the rhenium–osmium geochronometer to petroleum systems. American Association of Petroleum Geologists Bulletin 102, 1627-1657.

Mei, M., Bissada, K.K., Malloy, T.B., Darnell, L.M., Liu, Z., 2018. Origin of condensates and natural gases in the Almond Formation reservoirs in southwestern Wyoming, USA. Organic Geochemistry 124, 164-179.



Yakubova, S.G., Abilova, G.R., Tazeeva, E.G., Borisova, Y.Y., Milordov, D.V., Mironov, N.A., Gryaznov, P.I., Yakubov, M.R., 2018. Distribution of vanadium and vanadyl porphyrins during fractionation of resins of heavy sulfurous oils. Petroleum Science and Technology 36, 1319-1324.

Paleoclimatology/Palaeocenography

Bottini, C., Erba, E., 2018. Mid-Cretaceous paleoenvironmental changes in the western Tethys. Climate of the Past 14, 1147-1163.

Cao, W., Xi, D., Melinte-Dobrinescu, M.C., Jiang, T., Wise, S.W., Wan, X., 2018. Calcareous nannofossil changes linked to climate deterioration during the Paleocene–Eocene thermal maximum in Tarim Basin, NW China. Geoscience Frontiers 9, 1465-1478.

Dal Corso, J., Gianolla, P., Rigo, M., Franceschi, M., Roghi, G., Mietto, P., Manfrin, S., Raucsik, B., Budai, T., Jenkyns, H.C., Reymond, C.E., Caggiati, M., Gattolin, G., Breda, A., Merico, A., Preto, N., 2018. Multiple negative carbon-isotope excursions during the Carnian Pluvial Episode (Late Triassic). Earth-Science Reviews 185, 732-750.

de Bar, M.W., Stolwijk, D.J., McManus, J.F., Sinninghe Damsté, J.S., Schouten, S., 2108. A Late Quaternary climate record based on long chain diol proxies from the Chilean margin. Climate of the Past Discussions 2108, 1-34.

Doss, W., Marchitto, T.M., Eagle, R., Rashid, H., Tripati, A., 2018. Deconvolving the saturation state and temperature controls on benthic foraminiferal Li/Ca, based on downcore paired B/Ca measurements and coretop compilation. Geochimica et Cosmochimica Acta 236, 297-314.

Gallagher, S.J., Sagawa, T., Henderson, A.C.G., Saavedra-Pellitero, M., De Vleeschouwer, D., Black, H., Itaki, T., Toucanne, S., Bassetti, M.-A., Clemens, S., Anderson, W., Alvarez-Zarikian, C., Tada, R., 2018. East Asian monsoon history and paleoceanography of the Japan Sea over the last 460,000 years. Paleoceanography and Paleoclimatology 33, 683-702.


Hardisty, D.S., Lyons, T.W., Riedinger, N., Isson, T.T., Owens, J.D., Aller, R.C., Rye, D.M., Planavsky, N.J., Reinhard, C.T., Gill, B.C., Masterson, A.L., Asael, D., Johnston, D.T., 2018. An evaluation of sedimentary molybdenum and iron as proxies for pore fluid paleoredox conditions. American Journal of Science 318, 527-556.

Ji, S., Nie, J., Lechler, A., Huntington, K.W., Heitmann, E.O., Breecker, D.O., 2018. A symmetrical CO2 peak and asymmetrical climate change during the middle Miocene. Earth and Planetary Science Letters 499, 134-144.

Keigwin, L.D., Klotsko, S., Zhao, N., Reilly, B., Giosan, L., Driscoll, N.W., 2018. Deglacial floods in the Beaufort Sea preceded Younger Dryas cooling. Nature Geoscience 11, 599-604.

Lattaud, J., Lo, L., Huang, J.-J., Chou, Y.-M., Gorbarenko, S.A., Sinninghe Damsté, J.S., Schouten, S., 2018. A comparison of late quaternary organic proxy-based paleotemperature records of the central Sea of Okhotsk. Paleoceanography and Paleoclimatology 33, 732-744.

Li, J.X., Yue, L.P., Roberts, A.P., Hirt, A.M., Pan, F., Guo, L., Xu, Y., Xi, R.G., Guo, L., Qiang, X.K., Gai, C.C., Jiang, Z.X., Sun, Z.M., Liu, Q.S., 2018. Global cooling and enhanced Eocene Asian mid-latitude interior aridity. Nature Communications 9, Article 3026.

Mekik, F., 2018. Do proxies agree? δ18O, δ13C and Mg/Ca from tests of Neogloboquadrina dutertrei in the eastern equatorial Pacific. Geochimica et Cosmochimica Acta 236, 260-282.

O'Dogherty, L., Aguado, R., Baumgartner, P.O., Bill, M., Goričan, Š., Sandoval, J., Sequeiros, L., 2018. Carbon-isotope stratigraphy and pelagic biofacies of the Middle–Upper Jurassic transition in the Tethys–Central Atlantic connection. Palaeogeography, Palaeoclimatology, Palaeoecology 507, 129-144.

Owens, J.D., Lyons, T.W., Lowery, C.M., 2018. Quantifying the missing sink for global organic carbon burial during a Cretaceous oceanic anoxic event. Earth and Planetary Science Letters 499, 83-94.

Park, E., Hefter, J., Fischer, G., Mollenhauer, G., 2018. TEX86 in sinking particles in three eastern Atlantic upwelling regimes. Organic Geochemistry 124, 151-163.

Patterson, M.O., McKay, R., Naish, T., Bostock, H.C., Dunbar, R., Ohneiser, C., Woodard, S.C., Wilson, G., Caballero-Gill, R., 2018. A southwest Pacific perspective on long-term global trends in Pliocene-Pleistocene stable isotope records. Paleoceanography and Paleoclimatology 33, 825-839.

Peterson, C.D., Lisiecki, L.E., 2018. Deglacial carbon cycle changes observed in a compilation of 127 benthic δ13C time series (20–6 ka). Climate of the Past 14, 1229-1252.

Rainsley, E., Menviel, L., Fogwill, C.J., Turney, C.S.M., Hughes, A.L.C., Rood, D.H., 2018. Greenland ice mass loss during the Younger Dryas driven by Atlantic Meridional Overturning Circulation feedbacks. Scientific Reports 8, Article 11307.

Raiswell, R., Hardisty, D.S., Lyons, T.W., Canfield, D.E., Owens, J.D., Planavsky, N.J., Poulton, S.W., Reinhard, C.T., 2018. The iron paleoredox proxies: A guide to the pitfalls, problems and proper practice. American Journal of Science 318, 491-526.



Satolli, S., Lanci, L., Muttoni, G., Di Cencio, A., 2018. The Lower Toarcian Serrone Marls (Northern Apennines, Italy): A 3.5 Myr record of marl deposition in the aftermath of the T-OAE. Palaeogeography, Palaeoclimatology, Palaeoecology 508, 35-47.


Schmid, S., Smith, P.M., Woltering, M., 2018. A basin-wide record of the Late Cambrian Steptoean positive carbon isotope excursion (SPICE) in the Amadeus Basin, Australia. Palaeogeography, Palaeoclimatology, Palaeoecology 508, 116-128.

Schneider-Mor, A., Zilberman, T., Korngreen, D., 2018. Global and regional variations in tropical marine environments of Gondwana as revealed by a multi-stable isotope study, Middle Triassic (Anisian), Israel, Levant Basin. Palaeogeography, Palaeoclimatology, Palaeoecology 507, 115-128.


Tian, J., Ma, X., Zhou, J., Jiang, X., Lyle, M., Shackford, J., Wilkens, R., 2018. Paleoceanography of the east equatorial Pacific over the past 16 Myr and Pacific–Atlantic comparison: High resolution benthic foraminiferal δ18O and δ13C records at IODP Site U1337. Earth and Planetary Science Letters 499, 185-196.

Yao, W., Paytan, A., Wortmann, U.G., 2018. Large-scale ocean deoxygenation during the Paleocene-Eocene Thermal Maximum. Science 361, 804-806.

Zakharov, Y.D., Horacek, M., Popov, A.M., Bondarenko, L.G., 2018. Nitrogen and carbon isotope data of Olenekian to Anisian deposits from Kamenushka/South Primorye, far-eastern Russia and their palaeoenvironmental significance. Journal of Earth Science 29, 837-853.

Zhang, S., Planavsky, N.J., Krause, A.J., Bolton, E.W., Mills, B.J.W., 2018. Model based Paleozoic atmospheric oxygen estimates: a revisit to GEOCARBSULF. American Journal of Science 318, 557-589.

Zhang, Y.G., Liu, X., 2018. Export depth of the TEX86 signal. Paleoceanography and Paleoclimatology 33, 666-671.

EXTINCTION EVENTS

Aguilée, R., Gascuel, F., Lambert, A., Ferriere, R., 2018. Clade diversification dynamics and the biotic and abiotic controls of speciation and extinction rates. Nature Communications 9, Article 3013.

Fujisaki, W., Matsui, Y., Asanuma, H., Sawaki, Y., Suzuki, K., Maruyama, S., 2018. Global perturbations of carbon cycle during the Triassic–Jurassic transition recorded in the mid-Panthalassa. Earth and Planetary Science Letters 500, 105-116.

Lucas, S.G., 2018. Permian-Triassic charophytes: Distribution, biostratigraphy and biotic events. Journal of Earth Science 29, 778-793.

Stanley, G.D., Shepherd, H.M.E., Robinson, A.J., 2018. Paleoecological response of corals to the end-Triassic mass extinction: An integrational analysis. Journal of Earth Science 29, 879-885.

Precambrian Geochemistry

Groopman, E.E., Willingham, D.G., Meshik, A.P., Pravdivtseva, O.V., 2018. Discovery of fissionogenic Cs and Ba capture five years after Oklo reactor shutdown. Proceedings of the National Academy of Sciences 115, 8676-8681.


ORGANICS/MICROFOSSILS/MICROBIAL EVOLUTION

Alleon, J., Bernard, S., Le Guillou, C., Beyssac, O., Sugitani, K., Robert, F., 2018. Chemical nature of the 3.4 Ga Strelley Pool microfossils. Geochemical Perspectives Letters 7, 37-42.


Barlow, E.V., Van Kranendonk, M.J., 2018. Snapshot of an early Paleoproterozoic ecosystem: Two diverse microfossil communities from the Turee Creek Group, Western Australia. Geobiology 16, 449-475.


Delarue, F., Robert, F., Sugitani, K., Tartèse, R., Duhamel, R., Derenne, S., 2018. Nitrogen isotope signatures of microfossils suggest aerobic metabolism 3.0 Gyr ago. Geochemical Perspectives Letters 7, 32-36.


Goryl, M., Marynowski, L., Brocks, J.J., Bobrovskiy, I., Derkowski, A., 2018. Exceptional preservation of hopanoid and steroid biomarkers in Ediacaran sedimentary rocks of the East European Craton. Precambrian Research 316, 38-47.

Medina Ferrer, F., Bailey, J.V., Corsetti, F., Moldowan, J.M., Barbanti, S.M., Caron, D., Bryant-Huppert, J., 2018. Assessing biomarker syngeneity: An in situ approach using monoclonal antibodies. Organic Geochemistry 124, 112-122.

Mloszewska, A.M., Cole, D.B., Planavsky, N.J., Kappler, A., Whitford, D.S., Owttrim, G.W., Konhauser, K.O., 2018. UV radiation limited the expansion of cyanobacteria in early marine photic environments. Nature Communications 9, Article 3088.

Qin, S., Luo, P., Wang, T., Wang, L., Ma, K., 2018. Discovery and geological significance of high quality hydrocarbon source rocks in interglacial of Neoproterozoic in the eastern part of the southern margin of North China. Journal of Natural Gas Geoscience 3, 73-79.

Qu, Y., Lepland, A., van Zuilen, M.A., Whitehouse, M., Črne, A.E., Fallick, A.E., 2018. Sample-scale carbon isotopic variability and diverse biomass in the Paleoproterozoic Zaonega Formation, Russia. Precambrian Research 315, 222-231.

Sugitani, K., Kohama, T., Mimura, K., Takeuchi, M., Senda, R., Morimoto, H., 2018. Speciation of Paleoarchean life demonstrated by analysis of the morphological variation of lenticular microfossils from the Pilbara Craton, Australia. Astrobiology 18, 1057-1070.

Wiesendanger, R., Wacey, D., Tulej, M., Neubeck, A., Ivarsson, M., Grimaudo, V., Moreno-García, P., Cedeño-López, A., Riedo, A., Wurz, P., 2018. Chemical and optical identification of micrometer-sized 1.9 billion-year-old fossils by combining a miniature laser ablation ionization mass spectrometry system with an optical microscope. Astrobiology 18, 1071-1080.

PALEOCLIMATOLOGY/PALEOCENOGRAPHY

Bellefroid, E.J., Hood, A.v.S., Hoffman, P.F., Thomas, M.D., Reinhard, C.T., Planavsky, N.J., 2018. Constraints on Paleoproterozoic atmospheric oxygen levels. Proceedings of the National Academy of Sciences 115, 8104-8109.

Kipp, M.A., Stüeken, E.E., Yun, M., Bekker, A., Buick, R., 2018. Pervasive aerobic nitrogen cycling in the surface ocean across the Paleoproterozoic Era. Earth and Planetary Science Letters 500, 117-126.

Lang, X., Shen, B., Peng, Y., Xiao, S., Zhou, C., Bao, H., Kaufman, A.J., Huang, K., Crockford, P.W., Liu, Y., Tang, W., Ma, H., 2018. Transient marine euxinia at the end of the terminal Cryogenian glaciation. Nature Communications 9, Article 3019.

Ossa Ossa, F., Hofmann, A., Wille, M., Spangenberg, J.E., Bekker, A., Poulton, S.W., Eickmann, B., Schoenberg, R., 2018. Aerobic iron and manganese cycling in a redox-stratified Mesoarchean epicontinental sea. Earth and Planetary Science Letters 500, 28-40.

Tang, C., 2018. Did Earth drive itself to a snowball? Science Bulletin 63, 1032-1033.

CRUSTAL EVOLUTION

Miller, S.R., Mueller, P.A., Meert, J.G., Kamenov, G.D., Pivarunas, A.F., Sinha, A.K., Pandit, M.K., 2018. Detrital zircons reveal evidence of Hadean crust in the Singhbhum Craton, India. The Journal of Geology 126, 541-552.

Production/Engineering Geochemistry

Alasiri, H., Klein, M.T., 2018. Density functional theory probe of the hydrolysis of heavy hydrocarbon structural moieties in supercritical water. Energy & Fuels 32, 8700-8704.



Cordero-Lanzac, T., Palos, R., Hita, I., Arandes, J.M., Rodríguez-Mirasol, J., Cordero, T., Bilbao, J., Castaño, P., 2018. Revealing the pathways of catalyst deactivation by coke during the hydrodeoxygenation of raw bio-oil. Applied Catalysis B: Environmental 239, 513-524.

Pei, S., Wang, Y., Zhang, L., Huang, L., Cui, G., Zhang, P., Ren, S., 2018. An innovative nitrogen injection assisted in-situ conversion process for oil shale recovery: Mechanism and reservoir simulation study. Journal of Petroleum Science and Engineering 171, 507-515.




Zhang, Z., Zhang, P., Li, Z., Kan, A.T., Tomson, M.B., 2018. Laboratory evaluation and mechanistic understanding of the impact of ferric species on oilfield scale inhibitor performance. Energy & Fuels 32, 8348-8357.

ASPHALTENES

Baghban, A., Hekmati, R., Hajiali, M., Janghorban Lariche, M., Kamyab, M., 2018. Application of MLP-ANN as novel tool for estimation of effect of inhibitors on asphaltene precipitation reduction. Petroleum Science and Technology 36, 1272-1277.

Davudov, D., Moghanloo, R.G., 2019. A new model for permeability impairment due to asphaltene deposition. Fuel 235, 239-248.

Fouad, W.A., Abutaqiya, M.I.L., Mogensen, K., Yap, Y.F., Goharzadeh, A., Vargas, F.M., Vega, L.F., 2018. Predictive model for pressure–volume–temperature properties and asphaltene instability of crude oils under gas injection. Energy & Fuels 32, 8318-8328.


Nguyen, N.T., Kang, K.H., Lee, C.W., Kim, G.T., Park, S., Park, Y.-K., 2019. Structure comparison of asphaltene aggregates from hydrothermal and catalytic hydrothermal cracking of C5-isolated asphaltene. Fuel 235, 677-686.

Payan, F., de Klerk, A., 2018. Hydrogen transfer in asphaltenes and bitumen at 250 °C. Energy & Fuels.

Sedaghat, M., Rouhibakhsh, K., 2018. On prediction of asphaltene precipitation in different operational conditions utilization of LSSVM algorithm. Petroleum Science and Technology 36, 1292-1297.

Singh, M.B., Rampal, N., Malani, A., 2018. Structural behavior of isolated asphaltene molecules at the oil–water interface. Energy & Fuels 32, 8259-8267.

Sun, X., Jian, C., He, Y., Zeng, H., Tang, T., 2018. Probing the effect of salt on asphaltene aggregation in aqueous solutions using molecular dynamics simulations. Energy & Fuels 32, 8090-8097.

Taheri-Shakib, J., Rajabi-Kochi, M., Kazemzadeh, E., Naderi, H., Salimidelshad, Y., Esfahani, M.R., 2018. A comprehensive study of asphaltene fractionation based on adsorption onto calcite, dolomite and sandstone. Journal of Petroleum Science and Engineering 171, 863-878.

INTERFACES/EOR

Al-Sarihi, A., Zeinijahromi, A., Genolet, L., Behr, A., Kowollik, P., Bedrikovetsky, P., 2018. Effects of fines migration on residual oil during low-salinity waterflooding. Energy & Fuels 32, 8296-8309.

Alfarge, D., Wei, M., Bai, B., 2018. Numerical simulation study on miscible EOR techniques for improving oil recovery in shale oil reservoirs. Journal of Petroleum Exploration and Production Technology 8, 901-916.

Ansah, E.O., Sugai, Y., Nguele, R., Sasaki, K., 2018. Integrated microbial enhanced oil recovery (MEOR) simulation: Main influencing parameters and uncertainty assessment. Journal of Petroleum Science and Engineering 171, 784-793.

Bhui, U.K., Sanyal, S., Saha, R., Rakshit, S., Pal, S.K., 2018. Steady-state and time-resolved fluorescence spectroscopic study of petroleum crudes in aqueous-surfactant solutions: Its implications for enhanced oil recovery (EOR) during surfactant flooding. Fuel 234, 1081-1088.

Cui, L., Dubos, F., Bourrel, M., 2018. Novel alkyl-amine surfactants for CO2 emulsion assisted enhanced oil recovery. Energy & Fuels 32, 8220-8229.

Fu, C., Yu, J., Liu, N., 2018. Nanoparticle-stabilized CO2 foam for waterflooded residual oil recovery. Fuel 234, 809-813.

Geng, J., Ding, H., Han, P., Wu, Y., Bai, B., 2018. Transportation and potential enhanced oil recovery mechanisms of nanogels in sandstone. Energy & Fuels 32, 8358-8365.


Lashkarbolooki, M., Ayatollahi, S., 2018. Investigation of ionic liquids based on pyridinium and imidazolium as interfacial tension reducer of crude oil−water and their synergism with MgCl2. Journal of Petroleum Science and Engineering 171, 414-421.

Li, S., Zhang, K., Jia, N., Liu, L., 2018. Evaluation of four CO2 injection schemes for unlocking oils from low-permeability formations under immiscible conditions. Fuel 234, 814-823.

Nikolaev, V.F., Foss, L.E., Ilyasov, R.A., Timirgalieva, A.K., Shageev, A.F., 2019. Method for laboratory testing of solvents for enhanced oil recovery based on dispersiometry and thin layer chromatography. Fuel 235, 433-436.

Purswani, P., Karpyn, Z.T., 2019. Laboratory investigation of chemical mechanisms driving oil recovery from oil-wet carbonate rocks. Fuel 235, 406-415.

Ramírez-González, P.V., Zavala Arriaga, M.M., Escobar-Barrios, V.A., 2018. A rapid method for interfacial tension calculation between rock plug and crude oil based on contact angles, application for EOR. Petroleum Science and Technology 36, 1242-1249.

Sun, G., Hu, J., Wang, Z., Li, X., Wang, W., 2018. Dynamic investigation of microbial activity in microbial enhanced oil recovery (MEOR). Petroleum Science and Technology 36, 1265-1271.

Wang, D., Sun, S., Sha, T., Liu, T., Dong, H., Cui, K., Li, H., Gong, Y., Hou, J., Zhang, Z., Fu, P., 2018. Synergistic effect of silica nanoparticles and rhamnolipid on wettability alteration of low permeability sandstone rocks. Energy & Fuels 32, 8098-8107.

Wang, H., Luo, M., Lun, Z., Lv, C., Zhao, C., Zhao, Q., Lang, D., 2018. Determination and comparison of interfacial interactions between CO2, crude oil, and brine at reservoir conditions. Energy & Fuels 32, 8187-8192.

Wang, Q., Puerto, M.C., Warudkar, S., Buehler, J., Biswal, S.L., 2018. Recyclable amine-functionalized magnetic nanoparticles for efficient demulsification of crude oil-in-water emulsions. Environmental Science: Water Research & Technology.

Zaeri, M.R., Hashemi, R., Shahverdi, H., Sadeghi, M., 2018. Enhanced oil recovery from carbonate reservoirs by spontaneous imbibition of low salinity water. Petroleum Science 15, 564-576.

Zhao, S., Pu, W., Wei, B., Xu, X., 2019. A comprehensive investigation of polymer microspheres (PMs) migration in porous media: EOR implication. Fuel 235, 249-258.

HEAVY OIL PRODUCTION

Ahadi, A., Torabi, F., 2018. Insight into heavy oil recovery of cyclic solvent injection (CSI) utilizing C3H8/CH4 and C3H8/CH4/CO2. Petroleum 4, 337-346.

Delamaide, E., 2018. Senlac, the forgotten SAGD project. SPE Reservoir Evaluation & Engineering 21, 789-805, SPE-189438-PA.

Hassanpour, S., Malayeri, M.R., Riazi, M., Mousavi, S.M., Negahban, Z., 2018. On the impact of Co3O4 nanoparticles on interaction of heavy oil and brine mixtures. Journal of Petroleum Science and Engineering 171, 680-686.

Kosior, D., Ngo, E., Xu, Y., 2018. Aggregates in paraffinic froth treatment: Settling properties and structure. Energy & Fuels 32, 8268-8276.

Recent Sediments

Atwood, T.B., Madin, E.M.P., Harborne, A.R., Hammill, E., Luiz, O.J., Ollivier, Q.R., Roelfsema, C.M., Macreadie, P.I., Lovelock, C.E., 2018. Predators shape sedimentary organic carbon storage in a coral reef ecosystem. Frontiers in Ecology and Evolution 6, 110. doi: 110.3389/fevo.2018.00110.

Bockisch, C., Lorance, E.D., Hartnett, H.E., Shock, E.L., Gould, I.R., 2018. Kinetics and mechanisms of dehydration of secondary alcohols under hydrothermal conditions. ACS Earth and Space Chemistry 2, 821-832.

Cao, X., Schmidt-Rohr, K., 2018. Abundant nonprotonated aromatic and oxygen-bonded carbons make humic substances distinct from biopolymers. Environmental Science & Technology Letters 5, 476-480.

Cózar, A., Morillo-García, S., Ortega, M.J., Li, Q.P., Bartual, A., 2018. Macroecological patterns of the phytoplankton production of polyunsaturated aldehydes. Scientific Reports 8, Article 12282.

Crowe, S.A., Cox, R.P., Jones, C., Fowle, D.A., Santibañez-Bustos, J.F., Ulloa, O., Canfield, D.E., 2018. Decrypting the sulfur cycle in oceanic oxygen minimum zones. The ISME Journal 12, 2322-2329.

Fan, L.-F., Lin, S., Hsu, C.-W., Tseng, Y.-T., Yang, T.F., Huang, K.-M., 2018. Formation and preservation of authigenic pyrite in the methane dominated environment. Deep Sea Research Part I: Oceanographic Research Papers 138, 60-71.




Liu, J., Wang, J., Izon, G., Antler, G., Wang, Z., Zhao, J., Egger, M., 2018. Vivianite formation in methane-rich deep-sea sediments from the South China Sea. biogeosciences DIscussions 2018, 1-32.


Nemirovskaya, I.A., Redzhepova, Z.Y., 2018. Behavior of hydrocarbons in the mouth parts of Arctic rivers. Geochemistry International 56, 828-841.

Pellerin, A., Antler, G., Røy, H., Findlay, A., Beulig, F., Scholze, C., Turchyn, A.V., Jørgensen, B.B., 2018. The sulfur cycle below the sulfate-methane transition of marine sediments. Geochimica et Cosmochimica Acta 239, 74-89.

Rontani, J.-F., Amiraux, R., Lalande, C., Babin, M., Kim, H.-R., Belt, S.T., 2018. Use of palmitoleic acid and its oxidation products for monitoring the degradation of ice algae in Arctic waters and bottom sediments. Organic Geochemistry 124, 88-102.

Sinninghe Damsté, J.S., Rijpstra, W.I.C., Hopmans, E.C., den Uijl, M.J., Weijers, J.W.H., Schouten, S., 2018. The enigmatic structure of the crenarchaeol isomer. Organic Geochemistry 124, 22-28.


ATMOSPHERIC GEOCHEMISTRY

Millet, D.B., Alwe, H.D., Chen, X., Deventer, M.J., Griffis, T.J., Holzinger, R., Bertman, S.B., Rickly, P.S., Stevens, P.S., Léonardis, T., Locoge, N., Dusanter, S., Tyndall, G.S., Alvarez, S.L., Erickson, M.H., Flynn, J.H., 2018. Bidirectional ecosystem–atmosphere fluxes of volatile organic compounds across the mass spectrum: How many matter? ACS Earth and Space Chemistry 2, 764-777.


HYDROSPHERE GEOCHEMISTRY


Bartual, A., Morillo-García, S., Ortega, M.J., Cózar, A., 2018. First report on vertical distribution of dissolved polyunsaturated aldehydes in marine coastal waters. Marine Chemistry 204, 1-10.

Cartisano, C.M., Del Vecchio, R., Bianca, M.R., Blough, N.V., 2018. Investigating the sources and structure of chromophoric dissolved organic matter (CDOM) in the North Pacific Ocean (NPO) utilizing optical spectroscopy combined with solid phase extraction and borohydride reduction. Marine Chemistry 204, 20-35.

Cavan, E.L., Giering, S.L.C., Wolff, G.A., Trimmer, M., Sanders, R., 2018. Alternative particle formation pathways in the Eastern Tropical North Pacific's biological carbon pump. Journal of Geophysical Research: Biogeosciences 123, 2198-2211.

Coppola, A.I., Wiedemeier, D.B., Galy, V., Haghipour, N., Hanke, U.M., Nascimento, G.S., Usman, M., Blattmann, T.M., Reisser, M., Freymond, C.V., Zhao, M., Voss, B., Wacker, L., Schefuß, E., Peucker-Ehrenbrink, B., Abiven, S., Schmidt, M.W.I., Eglinton, T.I., 2018. Global-scale evidence for the refractory nature of riverine black carbon. Nature Geoscience 11, 584-588.

Fransner, F., Fransson, A., Humborg, C., Gustafsson, E., Tedesco, L., Hordoir, R., Nycander, J., 2018. Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters. Biogeosciences Discussions 2018, 1-27.

Griffin, C.G., Finlay, J.C., Brezonik, P.L., Olmanson, L., Hozalski, R.M., 2018. Limitations on using CDOM as a proxy for DOC in temperate lakes. Water Research 144, 719-727.


Ledesma, J.L.J., Kothawala, D.N., Bastviken, P., Maehder, S., Grabs, T., Futter, M.N., 2018. Stream dissolved organic matter composition reflects the riparian zone, not upslope soils in boreal forest headwaters. Water Resources Research 54, 3896-3912.

Liu, C.-H., Chu, W., Li, H., Boyd, S.A., Teppen, B.J., Mao, J., Lehmann, J., Zhang, W., 2019. Quantification and characterization of dissolved organic carbon from biochars. Geoderma 335, 161-169.

McKay, G., Korak, J.A., Rosario-Ortiz, F.L., 2018. Temperature dependence of dissolved organic matter fluorescence. Environmental Science & Technology 52, 9022-9032.


Song, K., Li, S., Wen, Z., Lyu, L., Shang, Y., 2018. Characterization of chromophoric dissolved organic matter in lakes on the Tibet Plateau, China, using spectroscopic analysis. Biogeosciences Discussions 2018, 1-50.

Tang, Y., Lemaitre, N., Castrillejo, M., Roca-Martí, M., Masqué, P., Stewart, G., 2018. The export flux of particulate organic carbon derived from 210Po / 210Pb disequilibria along the North Atlantic GEOTRACES GA01 (GEOVIDE) transect. Biogeosciences Discussions 2018, 1-40.

Zark, M., Dittmar, T., 2018. Universal molecular structures in natural dissolved organic matter. Nature Communications 9, Article 3178.

SOIL GEOCHEMISTRY



Fan, R., Yang, X., Drury, C.F., Zhang, Z., 2018. Curve-fitting techniques improve the mid-infrared analysis of soil organic carbon: a case study for Brookston clay loam particle-size fractions. Scientific Reports 8, Artcile 12174.

Gao, L., Zhou, Z., Reyes, A.V., Guo, L., 2018. Yields and characterization of dissolved organic matter from different aged soils in northern Alaska. Journal of Geophysical Research: Biogeosciences 123, 2035-2052.

Greenfield, L.M., Hill, P.W., Paterson, E., Baggs, E.M., Jones, D.L., 2018. Methodological bias associated with soluble protein recovery from soil. Scientific Reports 8, Article 11186.

Holdridge, G., Leigh, D.S., 2018. Stable carbon analysis of alluvial paleosols in the Mixteca Alta, Oaxaca, Mexico. Quaternary International 490, 60-73.

Jaeschke, A., Rethemeyer, J., Lappé, M., Schouten, S., Boeckx, P., Schefuß, E., 2018. Influence of land use on distribution of soil n-alkane δD and brGDGTs along an altitudinal transect in Ethiopia: Implications for (paleo)environmental studies. Organic Geochemistry 124, 77-87.


von der Lühe, B., Birk, J.J., Dawson, L., Mayes, R.W., Fiedler, S., 2018. Steroid fingerprints: Efficient biomarkers of human decomposition fluids in soil. Organic Geochemistry 124, 228-237.

Wiesmeier, M., Urbanski, L., Hobley, E., Lang, B., von Lützow, M., Marin-Spiotta, E., van Wesemael, B., Rabot, E., Ließ, M., Garcia-Franco, N., Wollschläger, U., Vogel, H.-J., Kögel-Knabner, I., 2019. Soil organic carbon storage as a key function of soils - A review of drivers and indicators at various scales. Geoderma 333, 149-162.

Zaccone, C., Beneduce, L., Lotti, C., Martino, G., Plaza, C., 2018. DNA occurrence in organic matter fractions isolated from amended, agricultural soils. Applied Soil Ecology 130, 134-142.

Zhang, Z., Wei, Z., Wang, J.J., Xiao, R., Meng, Y., Wu, H., Lyu, X., 2018. Ants alter molecular characteristics of soil organic carbon determined by pyrolysis-chromatography/mass spectrometry. Applied Soil Ecology 130, 91-97.

Remote Sensing-Hydrocarbon Seepage


Du, Z., Zhang, X., Luan, Z., Wang, M., Xi, S., Li, L., Wang, B., Cao, L., Lian, C., Li, C., Yan, J., 2018. In situ Raman quantitative detection of the cold seep vents and fluids in the chemosynthetic communities in the South China Sea. Geochemistry, Geophysics, Geosystems 19, 2049-2061.


Omrani, H., Raghimi, M., 2018. Origin of the mud volcanoes in the south east Caspian Basin, Iran. Marine and Petroleum Geology 96, 615-626.

Riedel, M., Scherwath, M., Römer, M., Veloso, M., Heesemann, M., Spence, G.D., 2018. Distributed natural gas venting offshore along the Cascadia margin. Nature Communications 9, Article 3264.

Rincón-Tomás, B., Duda, J.-P., Somoza, L., González, J., Schneider, D., Medialdea, T., Madureira, P., Hoppert, M., Reitner, J., 2018. Cold-water corals and hydrocarbon-rich seepage in the Pompeia Province (Gulf of Cádiz) – living on the edge. Biogeosciences Discussions 2018, 1-33.



Verweij, J.M., Nelskamp, S.N., Ten Veen, J.H., De Bruin, G., Geel, K., Donders, T.H., 2018. Generation, migration, entrapment and leakage of microbial gas in the Dutch part of the Southern North Sea Delta. Marine and Petroleum Geology 97, 493-516.

Source Rocks/Depositional Environments

Abay, T.B., Karlsen, D.A., Pedersen, J.H., Olaussen, S., Backer-Owe, K., 2018. Thermal maturity, hydrocarbon potential and kerogen type of some Triassic–Lower Cretaceous sediments from the SW Barents Sea and Svalbard. Petroleum Geoscience 24, 349-373.


Gupta, I., Rai, C., Sondergeld, C.H., Devegowda, D., 2018. Rock typing in Eagle Ford, Barnett, and Woodford formations. Reservoir Evaluation & Engineering 21, 654-670. SPE-189968-PA

Hackley, P.C., Valentine, B.J., Hatcherian, J.J., 2018. On the petrographic distinction of bituminite from solid bitumen in immature to early mature source rocks. International Journal of Coal Geology 196, 232-245.


Havelcová, M., Machovič, V., Sýkorová, I., Lapčák, L., Špaldoňová, A., Mach, K., Dvořák, Z., 2018. Duxite – Fossil resin of Miocene age. Organic Geochemistry 124, 190-204.

Huang, C., Yuan, X., Song, C., Yuan, J., Ni, X., Ma, X., Zhang, S., 2018. Characteristics, origin, and role of salt minerals in the process of hydrocarbon accumulation in the saline lacustrine basin of the Yingxi Area, Qaidam, China. Carbonates and Evaporites 33, 431-446.

Hubert, H.L., Rankey, E.C., Omelon, C., 2018. Organic matter, textures, and pore attributes of hypersaline lacustrine microbial deposits (Holocene, Bahamas). Journal of Sedimentary Research 88, 827-849.

Jaroszewicz, E., Bojanowski, M., Marynowski, L., Łoziński, M., Wysocka, A., 2018. Paleoenvironmental conditions, source and maturation of Neogene organic matter from the siliciclastic deposits of the Orava-Nowy Targ Basin. International Journal of Coal Geology 196, 288-301.

Landman, N.H., Cochran, J.K., Slovacek, M., Larson, N.L., Garb, M.P., Brezina, J., Witts, J.D., 2018. Isotope sclerochronology of ammonites (Baculites Compressus) from methane seep and non-seep sites in the Late Cretaceous Western Interior Seaway, USA: Implications for ammonite habitat and mode of life. American Journal of Science 318, 603-639.

Liao, J., Lu, H., Feng, Q., Zhou, Y., Shi, Q., Peng, P.a., Sheng, G., 2018. Identification of a novel C33 botryococcane and C33 botryococcanone in the Maoming Basin, China. Organic Geochemistry 124, 103-111.

Liu, Y., Gang, W., Chen, G., Sun, J., Jiang, C., 2018. Geochemical characteristics of aromatic hydrocarbons of Chang7 source rocks from the Yanchi-Dingbian area, Ordos Basin. Acta Sedimentologica Sinica 86, 818-828.


Mohamed, N.S., El Nady, M.M., Sharaf, L.M., 2018. Evaluation of possible source rocks and extracts characteristics from Safir-1x well, North Western Desert, Egypt. Petroleum Science and Technology 36, 1235-1241.

Perez, F., Devegowda, D., 2019. Spatial distribution of reservoir fluids in mature kerogen using molecular simulations. Fuel 235, 448-459.

Ponomareva, E.V., Burshtein, L.M., Kontorovich, A.E., Kostyreva, E.A., 2018. Organic carbon distribution in the Bazhenov horizon rocks of the western Siberian megabasin. Doklady Earth Sciences 481, 918-921.

Smirnov, M.B., Fadeeva, N.P., Borisov, R.S., Poludetkina, E.N., 2018. The characteristics of the organic matter of the Upper Devonian Domanik-type deposits in the northern and central regions of the Volga-Ural Basin according to saturated biomarkers composition. Geochemistry International 56, 812-827.

Tong, X., Hu, J., Xi, D., Zhu, M., Song, J., Peng, P.a., 2018. Depositional environment of the Late Santonian lacustrine source rocks in the Songliao Basin (NE China): Implications from organic geochemical analyses. Organic Geochemistry 124, 215-227.

Walasek, N., Loydell, D.K., Frýda, J., Männik, P., Loveridge, R.F., 2018. Integrated graptolite-conodont biostratigraphy and organic carbon chemostratigraphy of the Llandovery of

Kallholn quarry, Dalarna, Sweden. Palaeogeography, Palaeoclimatology, Palaeoecology 508, 1-16.

Walters, C.C., Peters, K.E., Moldowan, J.M., 2018. History of life from the hydrocarbon fossil record, in: Wilkes, H. (Ed.), Hydrocarbons, Oils and Lipids: Diversity, Origin, Chemistry and Fate. Springer International Publishing, pp. 1-35.

Wenau, S., Spiess, V., Keil, H., Fei, T., 2018. Localization and characterization of a gas bubble stream at a Congo deep water seep site using a 3D gridding approach on single-beam echosounder data. Marine and Petroleum Geology 97, 612-623.


Yalçin Erik, N., 2018. Biological marker indicators of paleo-depositional environment for the Eocene formations around Zara-Bolucan region (central anatolia, Turkey). Advances in Geo-Energy Research 2, 237-244.

Yihdego, Y., Salem, H.S., Kafui, B.G., Veljkovic, Z., 2018. Economic geology value of oil shale deposits: Ethiopia (Tigray) and Jordan. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 40, 2079-2096.

Yu, K., Cao, Y., Qiu, L., Sun, P., 2018. The hydrocarbon generation potential and migration in an alkaline evaporite basin: The Early Permian Fengcheng Formation in the Junggar Basin, northwestern China. Marine and Petroleum Geology 98, 12-32.

Zhang, S., Riva, J.F., 2018. The stratigraphic position and the age of the Ordovician organic-rich intervals in the northern Hudson Bay, Hudson Strait, and Foxe basins—evidence from graptolites. Canadian Journal of Earth Sciences 55, 897-904.


Zheng, D., Chang, S.-C., Perrichot, V., Dutta, S., Rudra, A., Mu, L., Kelly, R.S., Li, S., Zhang, Q., Zhang, Q., Wong, J., Wang, J., Wang, H., Fang, Y., Zhang, H., Wang, B., 2018. A Late Cretaceous amber biota from central Myanmar. Nature Communications 9, Article 3170.

Unconventional Resources


Alfi, M., Hosseini, S.A., Enriquez, D., Zhang, T., 2019. A new technique for permeability calculation of core samples from unconventional gas reservoirs. Fuel 235, 301-305.

Awadalla, T., Voskov, D., 2018. Modeling of gas flow in confined formations at different scales. Fuel 234, 1354-1366.

Chen, L., Jiang, Z., Liu, K., Gao, F., 2017. Quantitative characterization of micropore structure for organic-rich Lower Silurian shale in the Upper Yangtze Platform, South China: Implications for shale gas adsorption capacity. Advances in Geo-Energy Research 1, 112-123.


Cruz Luque, M.M., Urban-Rascon, E., Aguilera, R.F., Aguilera, R., 2018. Mexican unconventional plays: Geoscience, endowment, and economic considerations. SPE Reservoir Evaluation & Engineering 21, 533-549. SPE-189438-PA

Cui, X., Yang, E., Song, K., Wang, Y., 2018. The seepage model considering liquid/solid interaction in confined nanoscale pores. Geofluids 2018, Article 8302782.

Fink, R., Amann-Hildenbrand, A., Bertier, P., Littke, R., 2018. Pore structure, gas storage and matrix transport characteristics of lacustrine Newark shale. Marine and Petroleum Geology 97, 525-539.

Garcia-Fresca, B., Pinkston, D., Loucks, R.G., LeFever, R., 2018. The Three Forks playa lake depositional model: Implications for characterization and development of an unconventional carbonate play. American Association of Petroleum Geologists Bulletin 102, 1455-1488.

Han, S., Zhang, J., Horsfield, B., Wang, C., 2018. Shale oil and gas generating characteristics of lacustrine Shahejie Formation in eastern sag of Liaohe depression, Northeast China. International Journal of Oil, Gas and Coal Technology 19, 83-96.


Hazra, B., Wood, D.A., Vishal, V., Singh, A.K., 2018. Pore characteristics of distinct thermally mature shales: Influence of particle size on low-pressure CO2 and N2 adsorption. Energy & Fuels 32, 8175–8186.

Hussien, O.S., Elraies, K.A., Almansour, A., Husin, H., Mohd Shuhili, J.A.B., 2018. Beyond fracking: Enhancement of shale gas desorption via surface tension reduction and wettability alteration. Journal of Natural Gas Science and Engineering 57, 322-330.

Iqbal, O., Ahmad, M., Kadir, A.a., 2018. Effective evaluation of shale gas reservoirs by means of an integrated approach to petrophysics and geomechanics for the optimization of hydraulic fracturing: A case study of the Permian Roseneath and Murteree Shale Gas reservoirs, Cooper Basin, Australia. Journal of Natural Gas Science and Engineering 58, 34-58.

Jin, B., Nasrabadi, H., 2018. Phase behavior in shale organic/inorganic nanopores from molecular simulation. SPE Reservoir Evaluation & Engineering 21, 626-637. SPE-187307-PA

Khatibi, S., Ostadhassan, M., Xie, Z.H., Gentzis, T., Bubach, B., Gan, Z., Carvajal-Ortiz, H., 2019. NMR relaxometry a new approach to detect geochemical properties of organic matter in tight shales. Fuel 235, 167-177.



Li, J., Yu, T., Liang, X., Zhang, P., Chen, C., Zhang, J., 2017. Insights on the gas permeability change in porous shale. Advances in Geo-Energy Research 1, 69-73.

Li, Y.-F., Sun, W., Liu, X.-W., Zhang, D.-W., Wang, Y.-C., Liu, Z.-Y., 2018. Study of the relationship between fractures and highly productive shale gas zones, Longmaxi Formation, Jiaoshiba area in eastern Sichuan. Petroleum Science 15, 498-509.

Lin, D., Wang, J., Yuan, B., Shen, Y., 2017. Review on gas flow and recovery in unconventional porous rocks. Advances in Geo-Energy Research 1, 39-53.

Liu, M., Gadikota, G., 2018. Probing the influence of thermally induced structural changes on the microstructural evolution in shale using multiscale X-ray scattering measurements. Energy & Fuels 32, 8193-8201.

Liu, Y., Yao, Y., Liu, D., Zheng, S., Sun, G., Chang, Y., 2018. Shale pore size classification: An NMR fluid typing method. Marine and Petroleum Geology 96, 591-601.

Luo, Q., Gong, L., Qu, Y., Zhang, K., Zhang, G., Wang, S., 2018. The tight oil potential of the Lucaogou Formation from the southern Junggar Basin, China. Fuel 234, 858-871.




Mohtar, R.H., Shafiezadeh, H., Blake, J., Daher, B., 2019. Economic, social, and environmental evaluation of energy development in the Eagle Ford shale play. Science of The Total Environment 646, 1601-1614.

Nunn, J.A., Xiang, Y., Al, T.A., 2018. Investigation of partial water saturation effects on diffusion in shale. Applied Geochemistry 97, 93-101.

Ogunyomi, B.A., Dong, S., La, N., Lake, L.W., Kabir, C.S., 2018. An approach to modeling production decline in unconventional reservoirs. Journal of Petroleum Exploration and Production Technology 8, 871-886.

Pang, W., Jin, Z., 2019. Revisiting methane absolute adsorption in organic nanopores from molecular simulation and Ono-Kondo lattice model. Fuel 235, 339-349.


Singh, H., Cai, J., 2018. A mechanistic model for multi-scale sorption dynamics in shale. Fuel 234, 996-1014.

Song, R., Cui, M., 2018. Molecular simulation on competitive adsorption mechanism of CH4/CO2 on shale kerogen. Arabian Journal of Geosciences 11, Article 403.

Standnes, D.C., 2018. Implications of molecular thermal fluctuations on fluid flow in porous media and its relevance to absolute permeability. Energy & Fuels 32, 8024-8039.

Tandon, S., Heidari, Z., 2018. Effect of internal magnetic-field gradients on nuclear-magnetic-resonance measurements and nuclear-magnetic-resonance-based pore-network characterization. SPE Reservoir Evaluation & Engineering 21, 609-625. SPE-189438-PA


Wan, T., Liu, H.-X., 2018. Exploitation of fractured shale oil resources by cyclic CO2 injection. Petroleum Science 15, 552-563.

Wang, J., Wang, Z., Sun, B., Gao, Y., Wang, X., Fu, W., 2019. Optimization design of hydraulic parameters for supercritical CO2 fracturing in unconventional gas reservoir. Fuel 235, 795-809.

Wang, P., Zou, C., Li, X., Jiang, L., Li, J., Mei, J., Zhang, Z., Li, Q., 2018. Main geological controlling factors of shale gas enrichment and high yield in Zhaotong demonstration area. Acta Petrolei Sinica 39, 744-753.

Wang, Q., Qin, Y., Jia, W., Wang, Y., Zhang, W., Peng, P.a., 2018. Density and viscosity of tight oil from Yanchang Formation, Ordos Basin, China and the geochemical controls. Petroleum Science and Technology 36, 1298-1304.



Xi, Z., Tang, S., Wang, J., 2018. The reservoir characterization and shale gas potential of the Niutitang formation: Case study of the SY well in northwest Hunan Province, South China. Journal of Petroleum Science and Engineering 171, 687-703.

Xie, J., 2018. Rapid shale gas development accelerated by the progress in key technologies: A case study of the Changning–Weiyuan National Shale Gas Demonstration Zone. Natural Gas Industry B 5, 283-292.

Yu, C., Tran, H., Sakhaee-Pour, A., 2018. Pore size of shale based on acyclic pore model. Transport in Porous Media 124, 345-368.

Zou, J., Rezaee, R., Yuan, Y., 2018. Investigation on the adsorption kinetics and diffusion of methane in shale samples. Journal of Petroleum Science and Engineering 171, 951-958.

Abstracts

Abay, T.B., Karlsen, D.A., Pedersen, J.H., Olaussen, S., Backer-Owe, K., 2018. Thermal maturity, hydrocarbon potential and kerogen type of some Triassic–Lower Cretaceous sediments from the SW Barents Sea and Svalbard. Petroleum Geoscience 24, 349-373.

http://pg.lyellcollection.org/content/24/3/349.abstract

Rock-Eval and total organic carbon (TOC) analyses of 144 samples representing Triassic–Lower Cretaceous intervals from the SW Barents Sea (the Svalis Dome, the Nordkapp and Hammerfest basins, and the Bjarmeland Platform) and Svalbard demonstrate lateral variations in source rock properties. Good to excellent source rocks are present in the Lower–Middle Triassic Botneheia and Steinkobbe, and Upper Jurassic Hekkingen formations, 1 – 7 wt% and 6 – 19 wt% TOC, respectively. Hydrogen indices of 298 – 609 mg HC/g TOC in the Botneheia Formation from Svalbard, and 197 – 540 mg HC/g TOC in the Steinkobbe Formation of Svalis Dome suggest Type II (oil-prone) and Type II/III (oil/gas-prone) kerogens, respectively. The Kobbe Formation (Botneheia/Steinkobbe-equivalent) is organic-lean and generally gas-prone (Type III kerogen) on the Bjarmeland Platform and in the Nordkapp Basin, and is a good source rock with Type III/II kerogen in the Hammerfest Basin. In the investigated wells, the Hekkingen Formation is more oil-prone on the Bjarmeland Platform than in the Nordkapp Basin, while Lower Cretaceous samples have poor potential for oil. Upper Triassic samples show potential mainly for gas; however, coal/coaly-shale samples in well 7430/07-U-01 (Bjarmeland Platform) are oil/gas-prone. Most samples analysed are immature to early mature; thus, the variation in petroleum potential and kerogen type is a function of organic facies rather than maturity levels.


https://doi.org/10.1029/2018JG004556

Coastal salt marshes play an important role in mitigating global warming by removing atmospheric carbon at a high rate. We investigated the environmental controls and emergent scaling of major greenhouse gas (GHG) fluxes such as carbon dioxide (CO2) and methane (CH4) in coastal salt marshes by conducting data analytics and empirical modeling. The underlying hypothesis is that the salt marsh GHG fluxes follow emergent scaling relationships with their environmental drivers, leading to parsimonious predictive models. CO2 and CH4 fluxes, photosynthetically active radiation (PAR), air and soil temperatures, well water level, soil moisture, and porewater pH and salinity were measured during May–October 2013 from four marshes in Waquoit Bay and adjacent estuaries, MA, USA. The salt marshes exhibited high CO2 uptake and low CH4 emission, which did not significantly vary with the nitrogen loading gradient (5–126 kg · ha−1 · year−1) among the salt marshes. Soil temperature was the strongest driver of both fluxes, representing 2 and 4–5 times higher influence than PAR and salinity, respectively. Well water level, soil moisture, and pH did not have a predictive control on the GHG fluxes, although both fluxes were significantly higher during high tides than low tides. The results were leveraged to develop emergent power law‐based parsimonious scaling models to accurately predict the salt marsh GHG fluxes from PAR, soil temperature, and salinity (Nash‐Sutcliffe Efficiency = 0.80–0.91). The scaling models are available as a user‐friendly Excel spreadsheet named Coastal Wetland GHG Model to explore scenarios of GHG fluxes in tidal marshes under a changing climate and environment.

Adams, J.K., Martins, C.C., Rose, N.L., Shchetnikov, A.A., Mackay, A.W., 2018. Lake sediment records of persistent organic pollutants and polycyclic aromatic hydrocarbons in southern Siberia mirror the changing fortunes of the Russian economy over the past 70 years. Environmental Pollution 242, 528-538.

http://www.sciencedirect.com/science/article/pii/S0269749118301751

Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) have previously been detected in the surface sediments, water, and endemic organisms of Lake Baikal, a UNESCO World Heritage Site. The Selenga River is the primary source of freshwater to Lake Baikal, and transports pollutants accumulating in the Selenga River basin to the lake. Sources of POPs and PAHs in the Selenga River basin grew through the 20th century. In the present study, temporal changes in the concentrations of PAHs and POPs were reconstructed from two lakes in the Selenga River basin over the past 150 years using paleolimnological techniques. Increased concentrations in PAHs and PCBs were recorded initially in the 1930s. The 1940s–1980s was the period of greatest exposure to organic contamination, and concentrations of dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), hexachlorocyclohexanes (HCHs) and many PAHs peaked between the 1960s and 1980s in the two lakes. Declines in concentrations and fluxes were recorded for most PAHs and POPs in the 1980s and 1990s. Temporal trends in concentrations of total and individual compounds/congeners of PAH, PCBs, and polybrominated diphenyl ethers (PBDEs) indicate the contribution of both local and regional sources of contamination in the 20th and 21st centuries. Temporal variations in contaminants can be linked to economic and industrial growth in the former USSR after World War II and the economic decline of Russia in the late-1980s and early-1990s, as well as global trends in industrialization and development during the mid-20th century.


https://doi.org/10.1007/s13202-017-0377-4

A statistical technique for the pore-scale analyses of heterogeneity and representative elemental volume (REV) in unconventional shale rocks is hereby presented. First, core samples were obtained from shale formations. The images were scanned using microcomputed tomography (micro-CT) machine at 6.7 μm resolution with voxels of 990 × 990 × 1000. These were then processed, digitised, thresholded, segmented and features captured using numerical algorithms. This allows the segmentation of each sample into four distinct morphological entities consisting of pores, organic matter, shale grains and minerals. In order to analyse the degree of heterogeneity, Eagle Ford parallel sample was further cropped into 96 subsamples. Descriptive statistical approach was then used to evaluate the existence of heterogeneity within the subsamples. Furthermore, the Eagle Ford parallel and perpendicular samples were analysed for volumetric entities representative of the petrophysical variable, porosity, using corner point cropping technique. The results of porosity REV for Eagle ford parallel and perpendicular indicated sample representation at 300 μm voxel edge. Both pore volume distribution and descriptive statistical analyses suggested that a wide variation of heterogeneity exists at this scale of investigation. Furthermore, this experiment allows for adequate extraction of necessary information and structural parameters for pore-scale modelling and simulation. Additional studies focusing on re-evaluation at higher resolution are recommended.

Aguilée, R., Gascuel, F., Lambert, A., Ferriere, R., 2018. Clade diversification dynamics and the biotic and abiotic controls of speciation and extinction rates. Nature Communications 9, Article 3013.

https://doi.org/10.1038/s41467-018-05419-7

How ecological interactions, genetic processes, and environmental variability jointly shape the evolution of species diversity remains a challenging problem in biology. We developed an individual-based model of clade diversification to predict macroevolutionary dynamics when resource competition, genetic differentiation, and landscape fluctuations interact. Diversification begins with a phase of geographic adaptive radiation. Extinction rates rise sharply at the onset of the next phase. In this phase of niche self-structuring, speciation and extinction processes, albeit driven by biotic mechanisms (competition and hybridization), have essentially constant rates, determined primarily by the abiotic pace of landscape dynamics. The final phase of diversification begins when intense competition prevents dispersing individuals from establishing new populations. Species’ ranges shrink, causing negative diversity-dependence of speciation rates. These results show how ecological and microevolutionary processes shape macroevolutionary dynamics and rates; they caution against the notion of ecological limits to diversity, and suggest new directions for the phylogenetic analysis of diversification.

Ahadi, A., Torabi, F., 2018. Insight into heavy oil recovery of cyclic solvent injection (CSI) utilizing C3H8/CH4 and C3H8/CH4/CO2. Petroleum 4, 337-346.

http://www.sciencedirect.com/science/article/pii/S240565611730202X

In this study, a sandpack model with porosity and permeability of 32.3% and 9.4 D, and a heavy crude oil with viscosity of 6430 mPa.s were used to represent a typical thin heavy oil formation. First, different ratios of C3H8 to CH4 stream were prepared and their performance on Cyclic Solvent Injection (CSI) method was examined to quantify the optimum solvent concentration. Second, CO2 was introduced to the optimum quantified CH4-C3H8 mixture to investigate the extent to which CSI behavior changes by partially replacement of CH4 with CO2.

Results showed that ultimate oil recovery factor (RF) increased from 24.3% to 33.4% original oil in place (OOIP) when C3H8 concentration increased from 15 to 50 mol% in the CH4 stream. CSI tests with higher C3H8 concentration reached the maximum cyclic recovery with lower number of injection cycles - due to higher solubility of C3H8 compared with CH4. Solvent utilization factor (SUF) data also confirmed this as lesser volume of solvent with higher C3H8 concentration was required to produce oil.

Visual observations showed that the produced foamy oil lasted longer with higher concentration of C3H8 in the solvent (5 min for 15% C3H8 – 85% CH4 case versus 180 min for 50% C3H8 – 50% CH4 case). Upon addition of CO2 to the mixture, the solvent apparent solubility increased and foamy oil flow promoted. The highest cyclic C3H8-CH4 apparent solubility of 0.175 gr. solvent/100 gr. remaining oil jumped to 0.53 gr. solvent/100 gr. remaining oil when 35% mole fraction of CO2 replaced CH4. The highest ultimate oil RF of 44.11% OOIP was measured from eight cycle injection of 50% C3H8 – 15% CH4 – 35% CO2. This solvent also benefited from the longest stability of produced-oil foamy shape with recorded time of 217 min (including production time).

According to the results of this experimental study, it seems that there is an optimum fraction of C3H8 in CH4 stream injection in heavy oil systems (with viscosity in the vicinity of 6430 mPa s); the concentration beyond which ultimate oil recovery factor does not increase significantly (near 50 mol%). It is speculated that last cycles do not appreciably respond to heavy oil production mainly due to asphaltene getting precipitated within the model.

Al-Sarihi, A., Zeinijahromi, A., Genolet, L., Behr, A., Kowollik, P., Bedrikovetsky, P., 2018. Effects of fines migration on residual oil during low-salinity waterflooding. Energy & Fuels 32, 8296-8309.

https://doi.org/10.1021/acs.energyfuels.8b01732

A novel mechanism of residual oil reduction during low-salinity water flooding by induced fines migration and consequent permeability damage is discovered. Dry corefloods (without oil) with piecewise-constant decreasing salinity are conducted to verify the presence of movable fines that yield permeability decrease. Sequential two-phase coreflood tests are performed using the displacement of nonpolar oil by high-salinity water, followed by full resaturation of the core by nonpolar oil and low-salinity waterflooding. The test then continued in tertiary mode, in which brines of decreasing salinity were injected in the presence of residual oil. Four Berea cores with high clay content, one Bentheimer core with low clay content, and two artificial cores with no clay content were used for two-phase waterflooding experiments. Reduction in permeability for water, fines production, and reduction in residual oil saturation accompanied the abrupt salinity decrease in all tests. This effect is attributed to fines mobilization that is due to salinity decrease, followed by fines migration and straining in thin pore throats that resulted in local hydraulic resistance and consequent pore-scale flux diversion, yielding Sor reduction. The Sor dependencies of the induced formation damage are derived from five series of laboratory tests. All the laboratory tests confirmed the proposed Sor reduction mechanism by fines-assisted low-salinity waterflooding.

Alasiri, H., Klein, M.T., 2018. Density functional theory probe of the hydrolysis of heavy hydrocarbon structural moieties in supercritical water. Energy & Fuels 32, 8700-8704.


The thermochemistry and kinetics of hydrolysis in supercritical water were probed using density function theory (DFT). Four molecules (propane, dimethyl ether, 1,3-diphenylpropane, and dibenzyl ether) were selected for this study to compare the reactivity of molecules with and without a heteroatom on a saturated carbon. We found that the activation energy for compounds with a heteroatom attached to saturated carbon was lower than that for fully hydrocarbon systems. The fastest reaction among the four molecules was that for dibenzyl ether with water. The activation energy and pre-exponential factor of the dibenzyl ether reaction with water is rationalized in the context of experimental values.



A method for the trace analysis of polar micropollutants (MPs) by direct injection of surface water and groundwater was validated with ultrahigh-performance liquid chromatography using a core-shell biphenyl stationary phase coupled to time-of-flight high-resolution mass spectrometry. The validation was successfully conducted with 33 polar MPs representative for several classes of emerging contaminants. Identification and quantification were achieved by semi-automated processing of full-scan and data-independent acquisition MS/MS spectra. In most cases good linearity (R2 ≥ 0.99), recovery (75% to 125%) and intra-day (RSD < 20%) and inter-day precision (RSD < 10%) values were observed. Detection limits of 9 to 83 ng/L and 9 to 93 ng/L could be achieved in riverbank filtrate and surface water, respectively. A solid-phase extraction was additionally validated to screen

samples from full-scale reverse osmosis drinking water treatment at sub-ng/L levels and overall satisfactory analytical performance parameters were observed for RBF and reverse osmosis permeate. Applicability of the direct injection method is shown for surface water and riverbank filtrate samples from an actual drinking water source. Several targets linkable to incomplete removal in wastewater treatment and farming activities were detected and quantified in concentrations between 28 ng/L for saccharine in riverbank filtrate and up to 1 μg/L for acesulfame in surface water. The solid phase extraction method applied to samples from full-scale reverse osmosis drinking water treatment plant led to quantification of 8 targets between 6 and 57 ng/L in the feed water, whereas only diglyme was detected and quantified in reverse osmosis permeate. Our study shows that combining the chromatographic resolution of biphenyl stationary phase with the performance of time-of-flight high-resolution tandem mass spectrometry resulted in a fast, accurate and robust method to monitor polar MPs in source waters by direct injection with high efficiency.



The enhanced analytical performance of comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC–MS) has demonstrated significant advantages for geochemical investigations of crude oils. However, the conventional geochemical analysis of crude oils based on diagnostic ratios from specific petroleum biomarkers can be more laborious and time-consuming for GC×GC. Additionally, the extraction of biomarker patterns from the crude oils is more analyst-dependent; therefore, the discovery of less evident and/or new patterns can be more challenging. This work introduces the use of GC×GC–MS/SIM and chemometrics for selected monitoring of the petroleum biomarkers and efficient discovery of the most relevant geochemical features that differentiate inter-reservoir crude oils. Pixels-based analysis using principal component analysis (PCA) extracted the multivariate patterns in the biomarkers fingerprints that successfully distinguished inter-reservoir geochemical properties that could also be obtained by the conventional diagnostics ratio approach, such as (i) the predominant marine or lacustrine organic matter depositional environment of the source rocks, (ii) oil’s thermal maturity, and (iii) biodegradation level. Furthermore, a biomarker fingerprint that distinguishes similar crude oils among specific reservoirs was obtained using variable selection into partial least squares–discriminant analysis (PLS-DA). The discriminant power of the selected biomarkers was statistically ranked using one-way ANOVA F-test and null distribution analysis. GC×GC–MS/SIM alongside multistep chemometrics can potentially enhance the geochemistry features that distinguish crude oils according to their origins and/or degrees of chemical similarity.

Alfarge, D., Wei, M., Bai, B., 2018. Numerical simulation study on miscible EOR techniques for improving oil recovery in shale oil reservoirs. Journal of Petroleum Exploration and Production Technology 8, 901-916.

https://doi.org/10.1007/s13202-017-0382-7

Shale formations in North America such as Bakken, Niobrara, and Eagle Ford have huge oil in place, 100–900 billion barrels of oil in Bakken only. However, the predicted primary recovery is still below 10%. Therefore, seeking for techniques to enhance oil recovery in these complex plays is inevitable. Although most of the previous studies in this area recommended that CO2 would be the best EOR technique to improve oil recovery in these formations, pilot tests showed that natural gases

performance clearly exceeds CO2 performance in the field scale. In this paper, two different approaches have been integrated to investigate the feasibility of three different miscible gases which are CO2, lean gases, and rich gases. Firstly, numerical simulation methods of compositional models have been incorporated with local grid refinement of hydraulic fractures to mimic the performance of these miscible gases in shale reservoirs conditions. Implementation of a molecular diffusion model in the LS-LR-DK (logarithmically spaced, locally refined, and dual permeability) model has been also conducted. Secondly, different molar-diffusivity rates for miscible gases have been simulated to find the diffusivity level in the field scale by matching the performance for some EOR pilot tests which were conducted in Bakken formation of North Dakota, Montana, and South Saskatchewan. The simulated shale reservoirs scenarios confirmed that diffusion is the dominated flow among all flow regimes in these unconventional formations. Furthermore, the incremental oil recovery due to lean gases, rich gases, and CO2 gas injection confirms the predicted flow regime. The effect of diffusion implementation has been verified with both of single porosity and dual-permeability model cases. However, some of CO2 pilot tests showed a good match with the simulated cases which have low molar-diffusivity between the injected CO2 and the formation oil. Accordingly, the rich and lean gases have shown a better performance to enhance oil recovery in these tight formations. However, rich gases need long soaking periods, and lean gases need large volumes to be injected for more successful results. Furthermore, the number of huff-n-puff cycles has a little effect on the all injected gases performance; however, the soaking period has a significant effect. This research project demonstrated how to select the best type of miscible gases to enhance oil recovery in unconventional reservoirs according to the field-candidate conditions and operating parameters. Finally, the reasons beyond the success of natural gases and failure of CO2 in the pilot tests have been physically and numerically discussed.

Alfi, M., Hosseini, S.A., Enriquez, D., Zhang, T., 2019. A new technique for permeability calculation of core samples from unconventional gas reservoirs. Fuel 235, 301-305.


Unconventional reservoirs and their outstanding characteristics have introduced a new field of research in reservoir engineering. The main challenge arises from the fact that in tight formations pore-throat size lays in the range of a few nanometers to a few dozens of nanometers, which makes the estimation of permeability a difficult task. When developing a permeability model for shale media, it is very important to accommodate for surface adsorption and transient flow effects, in addition to slippage effect and Knudsen diffusion, in order to achieve an accurate model. Prediction of fluid flow inside shale rock needs development of new models that take into account not only the diffusive flow but also the effect of high amount of gas adsorbed to the surface of the pores. In this work, we have proposed a new semi-empirical method for calculation of gas permeability inside tight formations. The method uses experimental data obtained from core plugs (canister data) and an analytical solution of continuity equation coupled with gas desorption in tight porous media. By matching the production data from core plugs, we have been able to calculate gas permeability by solving the analytical equation. We have been able to capture the effect of pore pressure on permeability by using production data at various core saturation pressures. We also compared our model with two previously proposed models. The results of this study show that the permeability calculated using our model is closer to experimental measurements of similar rock samples and comparable with other models.

Alleon, J., Bernard, S., Le Guillou, C., Beyssac, O., Sugitani, K., Robert, F., 2018. Chemical nature of the 3.4 Ga Strelley Pool microfossils. Geochemical Perspectives Letters 7, 37-42.

http://www.geochemicalperspectivesletters.org/article1817

The biogenicity of putative traces of life found in early-Archean rocks is strongly debated. To date, only equivocal lines of evidence have been reported, which has prevented a full consensus from emerging. Here we report elemental and molecular data from individual organic microfossils preserved within the 3.4 billion-year-old cherts of the Strelley Pool Formation, Western Australia. The present results support the growing body of evidence advocating their biogenicity, promoting them as the oldest known authentic organic microfossils. These microfossils consist of nitrogen- and oxygen- rich organic molecules that have been only slightly degraded despite experiencing temperatures of ~300 °C. Such molecular preservation emphasises the palaeobiological potential of the Earth’s oldest geological record, whilst providing a promising window into the early biosphere.

Amiri, A., Baghayeri, M., Sedighi, M., 2018. Magnetic solid-phase extraction of polycyclic aromatic hydrocarbons using a graphene oxide/Fe3O4@polystyrene nanocomposite. Microchimica Acta 185, 393.

https://doi.org/10.1007/s00604-018-2928-x

A magnetic sorbent was fabricated by coating the magnetized graphene oxide with polystyrene (PS) to obtain a sorbent of the type GO-Fe3O4@PS. The chemical composition and morphology of the sorbent were characterized. The sorbent was employed for the enrichment of polycyclic aromatic hydrocarbons (PAHs) from water samples. Various parameters affecting the enrichment were investigated. The PAHs were then quantified by gas chromatography with flame ionization detection. Linear responses were found in the range of 0.03–100 ng mL−1 for naphthalene and 2-methylnaphthalene, and of 0.01–100 ng mL−1 for fluorene and anthracene. The detection limits (at an S/N ratio of 3) range between 3 and 10 pg mL−1. The relative standard deviations (RSDs) for five replicates at three concentration levels (0.05, 5 and 50 ng mL−1) of analytes ranged from 4.9 to 7.4%. The method was applied to the analysis of spiked real water samples. Relative recoveries are between 95.8 and 99.5%, and RSD% are <8.4%.

Ansah, E.O., Sugai, Y., Nguele, R., Sasaki, K., 2018. Integrated microbial enhanced oil recovery (MEOR) simulation: Main influencing parameters and uncertainty assessment. Journal of Petroleum Science and Engineering 171, 784-793.


The present study investigated the ability of a thermophilic anaerobic microbe (herein coded as AR80) for MEOR with the further objective to quantify the uncertainty of production forecast in terms of the cumulative probability distribution. A series of core flood experiments conducted in water-flooded Berea sandstone showed that up to 51% of initial oil-in-place was recovered when the plugs were treated with AR80 and shut-in for 14 days. Mainly, the oil recovery mechanisms were attributed to viscosity enhancement, wettability changes, permeability and flow effects. Matching the laboratory data using artificial intelligence: the optimized cumulative oil recovery could be achieved at an enthalpy of 894.2 J/gmol, Arrhenius frequency of 8.3, residual oil saturation of 20%, log of capillary number at microbe flooding stage of −1.26, and also depicted a history match error less than 3%. Therefrom, a sensitivity analysis conducted on reservoir shut-in period effect on oil recovery revealed that a relatively shorter shut-in period is recommended to warrant early incremental oil recovery effect for economical purposes. In addition, MEOR could enhance the oil recovery significantly if a larger capillary number (between 10−5 and 10−3.5) is attained. Per probabilistic estimation, MEOR could sustain already water-flooded well for a set period of time. This study

showed that there is a 20% frequency of increasing the oil recovery by above 20% when a mature water-flooded reservoir is further flooded with AR80 for 2 additional years. Lastly, it was demonstrated herein that increasing the nutrient (yeast extract) concentration (from 0.1 to 1% weight) had less or no significant effect on the oil viscosity and subsequent recovery.

Arora, V.K., Melton, J.R., Plummer, D., 2018. An assessment of natural methane fluxes simulated by the CLASS-CTEM model. Biogeosciences 15, 4683-4709.

https://www.biogeosciences.net/15/4683/2018/

Natural methane emissions from wetlands and fire, and soil uptake of methane, simulated using the Canadian Land Surface Scheme and Canadian Terrestrial Ecosystem (CLASS-CTEM) modelling framework, over the historical 1850–2008 period, are assessed by using a one-box model of atmospheric methane burden. This one-box model also requires anthropogenic emissions and the methane sink in the atmosphere to simulate the historical evolution of global methane burden. For this purpose, global anthropogenic methane emissions for the period 1850–2008 were reconstructed based on the harmonized representative concentration pathway (RCP) and Emission Database for Global Atmospheric Research (EDGAR) data sets. The methane sink in the atmosphere is represented using bias-corrected methane lifetimes from the Canadian Middle Atmosphere Model (CMAM). The resulting evolution of atmospheric methane concentration over the historical period compares reasonably well with observation-based estimates (correlation = 0.99, root mean square error = 35ppb). The modelled natural emissions are also assessed using an inverse procedure where the methane lifetimes required to reproduce the observed year-to-year increase in atmospheric methane burden are calculated based upon the specified global anthropogenic and modelled natural emissions that we have used here. These calculated methane lifetimes over the historical period fall within the uncertainty range of observation-based estimates. The present-day (2000–2008) values of modelled methane emissions from wetlands (169TgCH4yr−1) and fire (27TgCH4yr−1), methane uptake by soil (29TgCH4yr−1), and the budget terms associated with overall anthropogenic and natural emissions are consistent with estimates reported in a recent global methane budget that is based on top-down approaches constrained by observed atmospheric methane burden. The modelled wetland emissions increase over the historical period in response to both increases in precipitation and in atmospheric CO2 concentration. This increase in wetland emissions over the historical period yields evolution of the atmospheric methane concentration that compares better with observation-based values than the case when wetland emissions are held constant over the historical period.

Arranz-Otaegui, A., Gonzalez Carretero, L., Ramsey, M.N., Fuller, D.Q., Richter, T., 2018. Archaeobotanical evidence reveals the origins of bread 14,400 years ago in northeastern Jordan. Proceedings of the National Academy of Sciences 115, 7925-7930.

https://doi.org/10.1073/pnas.1801071115

Significance: Despite being one of the most important foodstuffs consumed in the modern world, the origins of bread are still largely unknown. Here we report the earliest empirical evidence for the preparation of bread-like products by Natufian hunter-gatherers, 4,000 years before the emergence of the Neolithic agricultural way of life. The discovery of charred food remains has allowed for the reconstruction of the chaîne opératoire for the early production of bread-like products. Our results suggest the use of the wild ancestors of domesticated cereals (e.g. wild einkorn) and club-rush tubers to produce flat bread-like products. Cereal-based meals such as bread probably become staples when Neolithic farmers started to rely on the cultivation of domesticated cereal species for their subsistence.

Abstract: The origins of bread have long been associated with the emergence of agriculture and cereal domestication during the Neolithic in southwest Asia. In this study we analyze a total of 24 charred food remains from Shubayqa 1, a Natufian hunter-gatherer site located in northeastern Jordan and dated to 14.6–11.6 ka cal BP. Our finds provide empirical data to demonstrate that the preparation and consumption of bread-like products predated the emergence of agriculture by at least 4,000 years. The interdisciplinary analyses indicate the use of some of the “founder crops” of southwest Asian agriculture (e.g., Triticum boeoticum, wild einkorn) and root foods (e.g., Bolboschoenus glaucus, club-rush tubers) to produce flat bread-like products. The available archaeobotanical evidence for the Natufian period indicates that cereal exploitation was not common during this time, and it is most likely that cereal-based meals like bread become staples only when agriculture was firmly established.

Asahina, K., Suzuki, N., 2018. Methylated naphthalenes as indicators for evaluating the source and source rock lithology of degraded oils. Organic Geochemistry 124, 46-62.


Methylated naphthalenes in oils/condensates are relatively resistant to bio- and thermal degradation and can be useful compounds for evaluating the source organic matter and source rock lithology. Assuming that cadinene, abietic acid, and cholesterol are major precursors of methylated naphthalenes in oils and condensates, laboratory hydrous pyrolysis experiments for these possible precursors were performed to understand the precursor/products relationship. The major dimethylnaphthalenes (DMNs) and trimethylnaphthalenes (TMNs) in pyrolyzates of cadinene and abietic acid were 1,2,5-TMN and 1,6- and 1,5-DMNs, whereas those in pyrolyzates of cholesterol were 2,3,6-TMN and 1,3- and 1,7-DMNs. The experimental results suggested that the dimethylnaphthalene ratio (DMR) of [1,5- + 1,6-DMNs]/[1,3- + 1,7-DMNs], and the trimethylnaphthalene ratio (TMR) of 1,2,5-TMN/2,3,6-TMN, can be potential indicators of source organic matter. The relative abundance of TMNs in the pyrolyzates was controlled largely by the maturity level and presence or absence of montmorillonite catalyst. The relative abundance of total TMNs to total MNs (ΣTMNs/ΣMNs ratio) can be a novel indicator for evaluating the clay-catalytic effect in source rocks. A lower ΣTMNs/ΣMNs ratio is related to clay-poor source rocks, such as coal, carbonates, and siliceous rocks, whereas a higher ΣTMNs/ΣMNs ratio suggests shaly (clay-rich) source rocks. The DMR, TMR, and ΣTMNs/ΣMNs ratios of various oils and condensates are very consistent with their source organic matter and source rock lithology, indicating that these indicators are practically useful.

Atwood, T.B., Madin, E.M.P., Harborne, A.R., Hammill, E., Luiz, O.J., Ollivier, Q.R., Roelfsema, C.M., Macreadie, P.I., Lovelock, C.E., 2018. Predators shape sedimentary organic carbon storage in a coral reef ecosystem. Frontiers in Ecology and Evolution 6, 110. doi: 10.3389/fevo.2018.00110.

https://www.frontiersin.org/article/10.3389/fevo.2018.00110

Trophic cascade theory predicts that predator effects should extend to influence carbon cycling in ecosystems. Yet, there has been little empirical evidence in natural ecosystems to support this hypothesis. Here, we use a naturally-occurring trophic cascade to provide evidence that predators help protect sedimentary organic carbon stocks in coral reef ecosystems. Our results show that predation risk altered the behaviour of herbivorous fish, where by it constrained grazing to areas close to the refuge of the patch reefs. Macroalgae growing in “riskier” areas further away from the reef were released from grazing pressure, which subsequently promoted carbon accumulation in the sediments underlying the macroalgal beds. Here we found that carbon stocks furthest away from the

reef edge were ~14% higher than stocks closest to the reef. Our results indicate that predators and herbivores play an important role in structuring carbon dynamics in a natural marine ecosystem, highlighting the need to conserve natural predator-prey dynamics to help maintain the crucial role of marine sediments in sequestering carbon.


https://doi.org/10.1111/gbi.12296

The 2.1‐billion‐year‐old (Ga) Francevillian series in Gabon hosts some of the oldest reported macroscopic fossils of various sizes and shapes, stimulating new debates on the origin, evolution and organization of early complex life. Here, we document ten representative types of exceptionally well‐preserved mat‐related structures, comprising “elephant‐skin” textures, putative macro‐tufted microbial mats, domal buildups, flat pyritized structures, discoidal microbial colonies, horizontal mat growth patterns, wrinkle structures, “kinneyia” structures, linear patterns and nodule‐like structures. A combination of petrographic analyses, scanning electron microscopy, Raman spectroscopy and organic elemental analyses of carbon‐rich laminae and microtexture, indicate a biological origin for these structures. The observed microtextures encompass oriented grains, floating silt‐sized quartz grains, concentrated heavy minerals, randomly oriented clays, wavy‐crinkly laminae and pyritized structures. Based on comparisons with modern analogues, as well as an average δ13C organic matter (Corg) composition of −32.94 ± 1.17‰ (1 standard deviation, SD) with an outlier of −41.26‰, we argue that the mat‐related structures contain relicts of multiple carbon pathways including heterotrophic recycling of photosynthetically derived Corg. Moreover, the relatively close association of the macroscopic fossil assemblages to the microbial mats may imply that microbial communities acted as potential benthic O2 oases linked to oxyphototrophic cyanobacterial mats and grazing grounds. In addition, the mat's presence likely improved the preservation of the oldest large colonial organisms, as they are known to strongly biostabilize sediments. Our findings highlight the oldest community assemblage of microscopic and macroscopic biota in the aftermath of the “Great Oxidation Event,” widening our understanding of biological organization during Earth's middle age.

Auchettl, R., Ruzi, M., Appadoo, D.R.T., Robertson, E.G., Ennis, C., 2018. Binary-phase acetonitrile and water aerosols: Infrared studies and theoretical simulation at Titan atmosphere conditions. ACS Earth and Space Chemistry 2, 811-820.

https://doi.org/10.1021/acsearthspacechem.8b00059

Acetonitrile (CH3CN) and water (H2O) ice particles were generated within a collisional cooling cell coupled to the Australian Synchrotron light source. The evolution of the aerosols was tracked by infrared spectroscopy compiled over the 4000–50 cm–1 region. Gas pressure and temperature conditions were varied to replicate the lower altitudes of the Titan atmosphere allowing for comparison to far-infrared features detected by the Cassini–Huygens spacecraft. The experimental spectra show that CH3CN and H2O particles are microheterogeneous in composition and spherical in shape. CH3CN lattice bands display temperature-dependent shifts in frequency, implying that pure β-phase is present in the mixed particles. In addition, a red shift identified for the C≡N fundamental stretching mode indicates dipole–dipole and π-electron side-directed hydrogen bond coupling between segregated CH3CN and H2O phases exclusively at the grain interface. Discrete dipole

approximation theory was implemented to evaluate various cluster architectures where segregated domains of pure CH3CN and H2O ices provided the best fit to experiment; confirming the infrared findings. Otherwise, simulations of competing architectures, such as core–shell and cubic shaped particles, did not provide convincing comparison to the aerosol spectra. We conclude that the far-infrared profiles for mixed CH3CN–H2O systems do not present as likely carriers for the unassigned 220 cm–1 “haystack” feature that has been identified in Titan’s lower atmosphere.

Awadalla, T., Voskov, D., 2018. Modeling of gas flow in confined formations at different scales. Fuel 234, 1354-1366.


Gas flow in fractured nano-porous shale formations is complicated by a hierarchy of structural features, ranging from nanopores to hydraulic fractures, and by several transport mechanisms that differ from standard viscous flow used in reservoir modeling. The use of accurate simulation techniques that honor the physical complexity of these reservoirs and capture the associated dynamics of nanopores is required. However, these simulations often necessitate a large amount of computational resources for field scale models and therefore require upscaling. Usually, the upscaling techniques are based on idealizations that do not reflect the discrete features of the reservoir. In this work, we first incorporate the physics model that describe dynamics of shale gas into a numerical Discrete Fracture and Matrix (DFM) model. The formulation of our DFM model applies an unstructured control volume finite difference approach with a two-point flux approximation. We then propose to upscale these detailed descriptions using two different techniques, with the major difference in their coarse-grid geometry. The first approach, referred to as Embedded DFM upscaling, relies on a structured Cartesian coarse grid. The second method, which we call the Multiple Sub-Regions (MSR) upscaling, introduces a flow based coarse grid to replicate the diffusive character of the pressure in the matrix. The required parameters for the coarse-scale model in both methods and the geometry of the subregions in the second method are determined using numerical homogenization of the underlying discrete fracture model. An accurate comparison with the fine-scale representation indicates an existence of an additional transient phenomenon at coarse scale. To account for this effect, the transmissibility of both types of coarse models is related to the pressure in our approach. Both upscaling methods are applied to simulate a shale-gas flow in 2D fractured reservoir models and are shown to provide results in close agreement with the underlying fine-scale model and with a considerable reduction in the computational time.


https://doi.org/10.1111/jam.13905

Aims: Biofilms are composed of micro‐organisms within a matrix of chemically complex polymer compounds and from these structures many unknown competitive factors are suggested that many considered are important consequences for biological control. This research was undertaken to study further the endophyte, Bacillus mojavensis and its relationships to biofilm and two classes of lipopeptides considered relevant for biocontrol of plant pathogens.

Methods and Results: Laser ablation electrospray ionization mass spectrometry and conventional MS/MS were used to study in situ biofilm production and the production of lipopeptides fengycin and surfactin in different strains of B. mojavensis in plate and test tube culture on two media. All strains

were capable of producing biofilm in vitro along with the accumulation of surfactin and fengycin although no concentration‐dependent relationship between lipopeptide accumulation and biofilm was observed.

Conclusion: All strains studied produce biofilms in culture with the accumulated surfactin and fengycin, demonstrating that endophytic bacteria also produced biofilms.

Significance and Impact of the Study: This study demonstrates that this endophytic species produced biofilms along with two biocontrol compounds of which one, surfactin, considered by others as a quorum sensor, highlighting its ecological role as a signalling mechanism in planta.

Baghban, A., Hekmati, R., Hajiali, M., Janghorban Lariche, M., Kamyab, M., 2018. Application of MLP-ANN as novel tool for estimation of effect of inhibitors on asphaltene precipitation reduction. Petroleum Science and Technology 36, 1272-1277.

https://doi.org/10.1080/10916466.2018.1468777

Sedimentation of heavy fractions of oil such as asphaltene is the main concern in different parts of petroleum industries like production and transportation. Due to this fact, the inhibition of asphaltene precipitation becomes one of the great interests in the petroleum industry. In the present investigation, multi-layer perceptron artificial neural network (MLP-ANN) was developed to estimate asphaltene precipitation reduction as a function of concentration and kind of inhibitors and oil properties. To this end, a total number of 75 data points were extracted from reliable source for training and validation of predicting algorithm. The outputs of MLP-ANN were compared with experimental data graphically and statistically, the determined coefficients of determination (R2) for training and testing are 0.996522 and 0.995239 respectively. These comparisons expressed the high quality of this algorithm in the prediction of asphaltene precipitation reduction. so the MLP-ANN can be used as a powerful machine for estimation of different processes in petroleum industries.

Balezin, M., Baryshnikova, K.V., Kapitanova, P., Evlyukhin, A.B., 2018. Electromagnetic properties of the Great Pyramid: First multipole resonances and energy concentration. Journal of Applied Physics 124, 034903.

https://doi.org/10.1063/1.5026556

Resonant response of the Great Pyramid interacting with external electromagnetic waves of the radio frequency range (the wavelength range is 200–600 m) is theoretically investigated. With the help of numerical simulations and multipole decomposition, it is found that spectra of the extinction and scattering cross sections include resonant features associated with excitation of the Pyramid's electromagnetic dipole and quadrupole moments. Electromagnetic field distributions inside the Pyramid at the resonant conditions are demonstrated and discussed for two cases, when the Pyramid is located in a homogeneous space or on a substrate. It is revealed that the Pyramid's chambers can collect and concentrate electromagnetic energy for the both surrounding conditions. In the case of the Pyramid on the substrate, at the shorter wavelengths, the electromagnetic energy accumulates in the chambers providing local spectral maxima for electric and magnetic fields. It is shown that basically the Pyramid scatters the electromagnetic waves and focuses them into the substrate region. The spectral dependence of the focusing effect is discussed.



The atmospheric deposition of water-soluble organic carbon (WSOC) contributes to the oceanic dissolved organic carbon (DOC) reservoir similarly to riverine discharge. However, information on the sources and composition of water-soluble organic matter (WSOM) in marine aerosols remains scarce, particularly at the molecular level. By using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), we identified approximately ten thousand molecular formulas in marine aerosols collected over the China coastal seas and the northwestern Pacific Ocean (NWPO). Even though their molecular compositions were highly variable (Bray-Curtis distance: 0.12–0.74), four distinctive origins, namely, marine biogenic sources, secondary organic aerosols (including CHO, CHON formulas derived from biogenic volatile organic compounds (VOCs) and organosulfate derived from both biogenic and anthropogenic VOCs), soil-derived organic matter (OM) and biomass and fossil fuel burning-derived polycyclic aromatics (including highly condensed organosulfur compounds) and unsaturated compounds, were discovered. Moreover, the different types of aerosols, including aerosols from the NWPO (marine-influenced), NWPO (dust) and China coastal seas, contained various proportions of organics from different sources. The NWPO (marine-influenced) aerosols were enriched with sea spray-derived OM, which was widely distributed and was likely related to marine biological activity. The NWPO (dust) aerosols exhibited a higher fraction of soil-derived OM, while the China coastal sea aerosols exhibited a much higher fraction of organosulfate than the other aerosols. Our investigation provided detailed molecular compositional and source information for marine aerosols over the northwestern Pacific Ocean, which can be utilized to understand the composition of WSOM deposited on the sea surface.

Bao, J., Wang, Z., Zhu, C., Wang, L., Chen, Y., Zhou, F., 2018. A new kind of crude oils and the geochemical characteristics in the Dongping area, Qaidam Basin. Acta Sedimentologica Sinica 86, 829-841.

http://www.cjxb.ac.cn/EN/abstract/abstract3911.shtml

Based on compositions of various biomarkers, the crude oils from northern Qaidam Basin have relatively higher Pr/Ph ratios (>2.0), moderate contents of rearranged steranes (diaC27/reC27=0.5-0.7), rearranged hopane (diaC30H/C30H=0.2-0.4) and neohopane (C29Ts/C29H=0.4-0.7), and lower gammacerane (gammacerane index<0.05), consistenting with depositional environments of Lower Jurassic source rocks. However, the crude oils from the north oilfields in western Qaidam Basin have the characteristics of lower Pr/Ph ratios (<0.8), lower contents of rearranged steranes (diaC27/reC27<0.1), rearranged hopane (diaC30H/C30H<0.05) and neohopane (C29Ts/C29H=0.2-0.4), and abundant gammacerane (gammacerane index=0.4-0.8), which may relate to saline source rocks. The crude oils from the Dongping area have a completely different biomarker assemblage from the two kinds of crude oils mentioned above in the study area, that is, abundant gammacerane (gammacerane index=1.2-3.0) coexists with high rearranged steranes (diaC27/reC27>0.4), rearranged hopane (diaC30H/C30H>0.7) and neohopane (C29Ts/C29H>1.5). It is very difficult to be explained by the distributions of gammacerane, rearranged steranes, rearranged hopanes and neohopanes in geological samples, because occurrence and formation of abundant gammacerane, rearranged biomarkers and neohopanes require completely different geological conditions. Furthermore, the relative compositions of various biomarkers in different crude oils from the study area suggest that this unusual biomarker assemblage in crude oils from the Dongping area is not from mixing of different crude oils, but an objective geological phenomenon, although its generation condition and

geochemical significance remain unknown at present. Therefore, the crude oils having unusual biomarker assemblage are a new kind of crude oils in the Qaidam Basin, and their source rocks are probably deposited in an acid and saline environment.

Barlow, E.V., Van Kranendonk, M.J., 2018. Snapshot of an early Paleoproterozoic ecosystem: Two diverse microfossil communities from the Turee Creek Group, Western Australia. Geobiology 16, 449-475.


Eighteen microfossil morphotypes from two distinct facies of black chert from a deep‐water setting of the c. 2.4 Ga Turee Creek Group, Western Australia, are reported here. A primarily in situ, deep‐water benthic community preserved in nodular black chert occurs as a tangled network of a variety of long filamentous microfossils, unicells of one size distribution and fine filamentous rosettes, together with relatively large spherical aggregates of cells interpreted as in‐fallen, likely planktonic, forms. Bedded black cherts, in contrast, preserve microfossils primarily within, but also between, rounded clasts of organic material that are coated by thin, convoluted carbonaceous films interpreted as preserved extracellular polymeric substance (EPS). Microfossils preserved within the clasts include a wide range of unicells, both much smaller and larger than those in the nodular black chert, along with relatively short, often degraded filaments, four types of star‐shaped rosettes and umbrella‐like rosettes. Large, complexly branching filamentous microfossils are found between the clasts. The grainstone clasts in the bedded black chert are interpreted as transported from shallower water, and the contained microfossils thus likely represent a phototrophic community. Combined, the two black chert facies provide a snapshot of a microbial ecosystem spanning shallow to deeper‐water environments, and an insight into the diversity of life present during the rise in atmospheric oxygen. The preserved microfossils include two new, distinct morphologies previously unknown from the geological record, as well as a number of microfossils from the bedded black chert that are morphologically similar to—but 400–500 Ma older than—type specimens from the c. 1.88 Ga Gunflint Iron Formation. Thus, the Turee Creek Group microfossil assemblage creates a substantial reference point in the sparse fossil record of the earliest Paleoproterozoic and demonstrates that microbial life diversified quite rapidly after the end of the Archean.

Bartual, A., Morillo-García, S., Ortega, M.J., Cózar, A., 2018. First report on vertical distribution of dissolved polyunsaturated aldehydes in marine coastal waters. Marine Chemistry 204, 1-10.


Polyunsaturated aldehydes (PUA) are bioactive molecules released by phytoplankton cells which can modify phytoplankton trophic interactions with grazers, bacteria or coexisting phytoplankters. Their ecological significance is still a matter of debate. There have been reports of PUA producers having been investigated at the ocean surface in both coastal and open areas, but there is little information regarding natural ranges and distribution of dissolved PUA (dPUA) once they are released. In this report, we provide novel information regarding vertical profiles of dPUA for a coastal area under two different hydrodynamical conditions (mixing and stratified waters). Results show significant concentrations of dPUA ranging from 0.061 nM to 1.87 nM during both periods. This data demonstrate a significant consistency of these compounds in coastal areas and may prove an indirect evidence of high turnover rates in seawater. The vertical distribution of dPUA showed high variability in stratification, and for the first time we describe “patches” of relatively high dPUA concentrations in the upper layer. We hypothesize that these patches of dPUA, correlated to the flow

of phytoplankton-derived sinking organic matter, could be significant for increasing the turnover rates of nutrients by triggering bacterial metabolism.

Bellefroid, E.J., Hood, A.v.S., Hoffman, P.F., Thomas, M.D., Reinhard, C.T., Planavsky, N.J., 2018. Constraints on Paleoproterozoic atmospheric oxygen levels. Proceedings of the National Academy of Sciences 115, 8104-8109.


Significance: Earth’s protracted oxygenation significantly transformed global biological and geochemical cycles. In particular, the rise of atmospheric oxygen above trace levels was an essential prerequisite for the development of animals. However, quantifying atmospheric oxygen levels in Earth’s middle age remains a daunting challenge. Here we use a combination of sedimentology, geochemical constraints, and oceanographic modeling to provide a quantitative estimate of Precambrian atmospheric oxygen. We provide evidence that atmospheric oxygen levels decreased significantly after the “Great Oxygenation Event” in Earth’s early history, to levels that would have negatively impacted the ecology of the earliest complex organisms.

Abstract: The oxygenation of Earth’s surface environment dramatically altered key biological and geochemical cycles and ultimately ushered in the rise of an ecologically diverse biosphere. However, atmospheric oxygen partial pressures (pO2) estimates for large swaths of the Precambrian remain intensely debated. Here we evaluate and explore the use of carbonate cerium (Ce) anomalies (Ce/Ce*) as a quantitative atmospheric pO2 proxy and provide estimates of Proterozoic pO2 using marine carbonates from a unique Precambrian carbonate succession—the Paleoproterozoic Pethei Group. In contrast to most previous work, we measure Ce/Ce* on marine carbonate precipitates that formed in situ across a depth gradient, building on previous detailed sedimentology and stratigraphy to constrain the paleo-depth of each sample. Measuring Ce/Ce* across a full platform to basin depth gradient, we found only minor depleted Ce anomalies restricted to the platform and upper slope facies. We combine these results with a Ce oxidation model to provide a quantitative constraint on atmospheric pO2 1.87 billion years ago (Ga). Our results suggest Paleoproterozoic atmospheric oxygen concentrations were low, near 0.1% of the present atmospheric level. This work provides another crucial line of empirical evidence that atmospheric oxygen levels returned to low concentrations following the Lomagundi Event, and remained low enough for large portions of the Proterozoic to have impacted the ecology of the earliest complex organisms.

Bhui, U.K., Sanyal, S., Saha, R., Rakshit, S., Pal, S.K., 2018. Steady-state and time-resolved fluorescence spectroscopic study of petroleum crudes in aqueous-surfactant solutions: Its implications for enhanced oil recovery (EOR) during surfactant flooding. Fuel 234, 1081-1088.


Surfactant flooding, a widely used chemical enhanced oil recovery (EOR) method, involves reduction of interfacial tension of the crude oil-aqueous surfactant system. During the surfactant flooding micelle structures have been formed in aqueous media where crude oil components are entrapped inside it. The nature of the surfactants in the aqueous injection fluids and the crude oil compositions are the key controlling factors for understanding the efficacy of the surfactant flooding during EOR. Therefore, understanding of the molecular level interaction between crude oils and aqueous surfactant solutions is very crucial for designing injection fluids during surfactant flooding for subsurface reservoirs having different types of crude oils. Two crude oils (Cambay basin, India) and three surfactants: cationic (cetyltrimethylammonium bromide i.e. CTAB), anionic (sodium dodecyl sulfate

i.e. SDS) and neutral (Triton X-100 i.e. TX100) were used in this study for understanding their interaction behavior. The chemical characterization by various analytical methods supports the presence of different sizes of the fused aromatic ring (FAR) associated with the polycyclic aromatic hydrocarbons (PAH) of the used crude oils. In this study, we have investigated the type of oil components present in the micelles formed by the surfactant solutions of various charges using steady-state and time-resolved fluorescence spectroscopic measurements. The extracted oil components in the micelles of different charges show different emission peaks with varying excitation wavelength and different fluorescence lifetime, indicating incorporation of PAH with variable sizes of FAR. Ionic surfactants (CTAB and SDS) are more compatible to exploit small (2–3 FAR) as well as medium (4–7 FAR) PAH structures whereas non-ionic surfactant (TX100) dominantly entraps medium PAH structures within their micelles. This study established that the intrinsic fluorescence of the crude oil can monitor its interaction with surfactant micelle of different charges and helps to design effective injection fluids for optimized crude oil recovery during surfactant flooding.


https://www.frontiersin.org/article/10.3389/fmicb.2018.01768

The recent discovery of cyanobacteria forming intracellular amorphous calcium carbonate (ACC) has challenged the former paradigm suggesting that cyanobacteria-mediated carbonatogenesis was exclusively extracellular. Yet, the mechanisms of intracellular biomineralization in cyanobacteria and in particular whether this takes place within an intracellular microcompartment, remain poorly understood. Here, we analyzed six cyanobacterial strains forming intracellular ACC by transmission electron microscopy. We tested two different approaches to preserve as well as possible the intracellular ACC inclusions: (i) freeze-substitution followed by epoxy embedding and room-temperature ultramicrotomy and (ii) high-pressure freezing followed by cryo-ultramicrotomy, usually referred to as cryo-electron microscopy of vitreous sections (CEMOVIS). We observed that the first method preserved ACC well in 500-nm-thick sections but not in 70-nm-thick sections. However, cell ultrastructures were difficult to clearly observe in the 500-nm-thick sections. In contrast, CEMOVIS provided a high preservation quality of bacterial ultrastructures, including the intracellular ACC inclusions in 50-nm-thick sections. ACC inclusions displayed different textures, suggesting varying brittleness, possibly resulting from different hydration levels. Moreover, an electron dense envelope of ~2.5 nm was systematically observed around ACC granules in all studied cyanobacterial strains. This envelope may be composed of a protein shell or a lipid monolayer, but not a lipid bilayer as usually observed in other bacteria forming intracellular minerals. Overall, this study evidenced that ACC inclusions formed and were stabilized within a previously unidentified bacterial microcompartment in some species of cyanobacteria.

Bockisch, C., Lorance, E.D., Hartnett, H.E., Shock, E.L., Gould, I.R., 2018. Kinetics and mechanisms of dehydration of secondary alcohols under hydrothermal conditions. ACS Earth and Space Chemistry 2, 821-832.


Alcohol dehydration by elimination of water is central to a series of functional group interconversions that have been proposed as a reaction pathway that connects hydrocarbons and carboxylic acids under

geochemically relevant hydrothermal conditions such as in sedimentary basins. Hydrothermal dehydration of alcohols is an example of an organic reaction that is quite different from the corresponding chemistry under ambient laboratory conditions. In hydrothermal dehydration, water acts as the solvent and provides the catalyst, and no additional reagents are required. This stands in contrast to the same reaction at ambient conditions, where concentrated strong acids are required. Hydrothermal dehydration is thus of potential interest in the context of green chemistry. We investigated the mechanism of hydrothermal alcohol dehydration for a series of secondary alcohols using studies of kinetics and stereoelectronic effects to establish reaction mechanisms. The E1 elimination mechanism dominates over the corresponding E2 mechanism, with the E2 mechanism being competitive with E1 only for the most favorable stereoelectronically restricted alcohols included in the present study. These results are relevant to understanding the kinetics and product distributions of alcohol dehydration reactions in natural geologic systems and can guide the development of organic chemical reactions that mimic geologic organic reactions under laboratory green chemistry conditions.



In the Lower Bajocian of the Jebel Bou Kendill section (Central High Atlas Mountain), three peculiar levels of authigenic carbonates are observed within the carbonate-poor Agoudim III Member. Morphological, sedimentological and geochemical evidences indicate that the two upper levels have been deposited at a hydrocarbon seep site, whereas the lowermost level likely underlines the zone where hydrocarbon fluids were generated. The first seep carbonate level is made of mineralized burrows that have acted as fluid conduits leading to a conspicuous cap carbonate bed on top of which several chimneys and chemoherm structures are embedded. Hence, this carbonate bed is a fossilized sea-floor carbonate crust. The second seep carbonate level is made of chemoherm structures buttressed against the first carbonate beds of the Agoudim IV Member. They were probably formed within the sedimentary column, close to the sea floor.

Similar seep carbonates are observed regionally within the Agoudim III Member in the highly subsiding Central High Atlas troughs. A relationship between these seep carbonates occurrence and the late Early Bajocian global environmental perturbation can be deduced, as this latter has led to the deposition of a relatively organic-matter rich sedimentary sequence in these troughs via seawater eutrophication. The decomposition by bacterial activity of this organic matter, aided by rapid burial rates, has led to the generation of alkaline-rich fluids promoting the precipitation of the seep carbonates. A similar relationship between transient environmental perturbations and seep carbonates occurrence is observed in numerous Mesozoic examples and can be explained by the fact that hydrocarbon-seeps are supply-limited systems. Transient deviation from the Mesozoic greenhouse climate norm, either toward hothouse or coldhouse climates, favours the deposition of organic-rich sediments or transient methane storage, respectively, hence increasing the likelihood for the formation of hydrocarbon seepage.

Bond-Lamberty, B., Bailey, V.L., Chen, M., Gough, C.M., Vargas, R., 2018. Globally rising soil heterotrophic respiration over recent decades. Nature 560, 80-83.

https://doi.org/10.1038/s41586-018-0358-x

Global soils store at least twice as much carbon as Earth’s atmosphere. The global soil-to-atmosphere (or total soil respiration, RS) carbon dioxide (CO2) flux is increasing, but the degree to which climate change will stimulate carbon losses from soils as a result of heterotrophic respiration (RH) remains highly uncertain. Here we use an updated global soil respiration database to show that the observed soil surface RH:RS ratio increased significantly, from 0.54 to 0.63, between 1990 and 2014 (P = 0.009). Three additional lines of evidence provide support for this finding. By analysing two separate global gross primary production datasets, we find that the ratios of both RH and RS to gross primary production have increased over time. Similarly, significant increases in RH are observed against the longest available solar-induced chlorophyll fluorescence global dataset, as well as gross primary production computed by an ensemble of global land models. We also show that the ratio of night-time net ecosystem exchange to gross primary production is rising across the FLUXNET201512 dataset. All trends are robust to sampling variability in ecosystem type, disturbance, methodology, CO2 fertilization effects and mean climate. Taken together, our findings provide observational evidence that global RH is rising, probably in response to environmental changes, consistent with meta-analyses and long-term experiments. This suggests that climate-driven losses of soil carbon are currently occurring across many ecosystems, with a detectable and sustained trend emerging at the global scale.

Bottini, C., Erba, E., 2018. Mid-Cretaceous paleoenvironmental changes in the western Tethys. Climate of the Past 14, 1147-1163.

https://doi.org/10.5194/cp-14-1147-2018

We present a continuous record of surface water temperature and fertility variations through the latest Barremian–Cenomanian interval (ca. 27Myr) based on calcareous nannofossil abundances from the western Tethys. The nannofossil temperature index, calibrated with TEX86 sea surface temperatures, suggests that warmest (34–36°C) conditions were reached during oceanic anoxic event (OAE) 1a onset, the Aptian–Albian boundary interval hyperthermals (113, Kilian level and Urbino level OAE 1b) and during a ca. 4Myr long phase in the middle Albian. Coolest temperatures (29°C) correspond instead to the late Aptian. Generally warm conditions characterized the Albian followed by a progressive cooling trend that started in the latest Albian (at the Marne a Fucoidi–Scaglia Bianca Formation transition). Temperate conditions occurred in the Cenomanian with frequent short-term variations highlighted by abundance peaks of the cold-water nannofossil species E. floralis and R. parvidentatum. Mid-Cretaceous surface water fertility was rather fluctuating and mostly independent from climatic conditions as well as from black shales intervals. Intense warming and fertility spikes were systematically associated only with black shales of OAE 1a and of the Aptian–Albian boundary hyperthermals. The Albian–Cenomanian rhythmic black shales are, in fact, associated with varying long-term climatic and fertility conditions. The similarity of western Tethys climatic and fertility fluctuations during OAE 1a, OAE 1b, the middle Albian and OAE 1d with nannofossil-based records from other basins indicated that these paleoenvironmental conditions were affecting the oceans at supra-regional to global scale.

Brasier, A., Wacey, D., Rogerson, M., Guagliardo, P., Saunders, M., Kellner, S., Mercedes-Martin, R., Prior, T., Taylor, C., Matthews, A., Reijmer, J., 2018. A microbial role in the construction of Mono Lake carbonate chimneys? Geobiology 16, 540-555.


Lacustrine carbonate chimneys are striking, metre-scale constructions. If these were bioinfluenced constructions, they could be priority targets in the search for early and extraterrestrial microbial life. However, there are questions over whether such chimneys are built on a geobiological framework or

are solely abiotic geomorphological features produced by mixing of lake and spring waters. Here, we use correlative microscopy to show that microbes were living around Pleistocene Mono Lake carbonate chimneys during their growth. A plausible interpretation, in line with some recent works by others on other lacustrine carbonates, is that benthic cyanobacteria and their associated extracellular organic material (EOM) formed tubular biofilms around rising sublacustrine spring vent waters, binding calcium ions and trapping and binding detrital silicate sediment. Decay of these biofilms would locally have increased calcium and carbonate ion activity, inducing calcite precipitation on and around the biofilms. Early manganese carbonate mineralisation was directly associated with cell walls, potentially related to microbial activity though the precise mechanism remains to be elucidated. Much of the calcite crystal growth was likely abiotic, and no strong evidence for either authigenic silicate growth or a clay mineral precursor framework was observed. Nevertheless, it seems likely that the biofilms provided initial sites for calcite nucleation and encouraged the primary organised crystal growth. We suggest that the nano-, micro- and macroscale fabrics of these Pleistocene Mono Lake chimneys were affected by the presence of centimetre-thick tubular and vertically stacked calcifying microbial mats. Such carbonate chimneys represent a promising macroscale target in the exploration for ancient or extraterrestrial life.

Braukmüller, N., Wombacher, F., Hezel, D.C., Escoube, R., Münker, C., 2018. The chemical composition of carbonaceous chondrites: Implications for volatile element depletion, complementarity and alteration. Geochimica et Cosmochimica Acta 239, 17-48.


In Earth and planetary sciences, the chemical composition of chondritic meteorites provides an essential reference to constrain the composition and differentiation history of planetary reservoirs. Yet, for many trace elements, and in particular for volatile trace elements the composition of chondrites is not well constrained. Here we present new compositional data for carbonaceous chondrites with an emphasis on the origin of the volatile element depletion pattern. Our database includes 25 carbonaceous chondrites from 6 different groups (CI, CM, CR, CV, CO, CK), two ungrouped carbonaceous chondrites and Murchison powder samples heated up to 1000 °C in O2 or Ar gas streams, respectively. A total of 51 major and trace elements were analyzed by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS), using chondrite-matched calibration solutions. Our results confirm that parent body alteration and terrestrial weathering only have minor effects on the bulk chondrite compositions. Thermal metamorphism can lead to the loss of some volatile elements, as best observed in the heating experiments and two thermally overprinted chondrites Y-980115 (CI) and EET 96026 (CV4/5 or CK4/5). The effects of aqueous alteration and terrestrial weathering on the Antarctic samples are difficult to discriminate. Both processes may redistribute fluid mobile elements such as K, Na, Rb, U and the light rare earth elements (LREE) within the meteorite. In hot desert finds, the typical weathering effects are enrichments of Sr, Ba and U and a depletion of S.

In general, moderately volatile elements with 50% condensation temperatures (TC) ranging from 1250 K to 800 K show an increasing depletion, whereas 11 moderately volatile elements with 50% TC

between 800 K and 500 K are unfractionated from each other in most samples. Their extent of depletion is characteristic for the different chondrite groups. Because of this well-defined “hockey stick” pattern, we propose to divide the moderately volatile elements into two subgroups, the ‘slope volatile elements’ and the unfractionated ‘plateau volatile elements’ with lower TC. Notably, the abundances of plateau volatile elements exhibit a co-variation with the matrix abundances of the respective host meteorites. Carbonaceous chondrite matrices are likely mixes of: (i) CI-like material and (ii) chondrule-related matrix. Chondrule-related matrix is expected to be depleted in volatile elements relative to CI and likely formed contemporaneously with chondrules, leading to chondrule-

matrix complementarity. The addition of CI-like material only changed the absolute elemental concentrations of bulk matrix and bulk chondrite, while refractory and main component element ratios such as Mg/Si remain unaffected. Such a model can also account for the co-existence of low temperature CI-like material and high temperature chondrule and chondrule-related matrix. However, elevated volatile element abundances observed in chondrules still provide a challenge for the model as proposed here.

Breitenbach, S.F.M., Mleneck-Vautravers, M.J., Grauel, A.-L., Lo, L., Bernasconi, S.M., Müller, I.A., Rolfe, J., Gázquez, F., Greaves, M., Hodell, D.A., 2018. Coupled Mg/Ca and clumped isotope analyses of foraminifera provide consistent water temperatures. Geochimica et Cosmochimica Acta 236, 283-296.


The reliable determination of past seawater temperature is fundamental to paleoclimate studies. We test the robustness of two paleotemperature proxies by combining Mg/Ca and clumped isotopes (Δ47) on the same specimens of core top planktonic foraminifera. The strength of this approach is that Mg/Ca and Δ47 are measured on the same specimens of foraminifera, thereby providing two independent estimates of temperature. This replication constitutes a rigorous test of individual methods with the advantage that the same approach can be applied to fossil specimens. Aliquots for Mg/Ca and clumped analyses are treated in the same manner following a modified cleaning procedure of foraminifera for trace element and isotopic analyses. We analysed eight species of planktonic foraminifera from coretop samples over a wide range of temperatures from 2 to 29°C. We provide a new clumped isotope temperature calibrations using subaqueous cave carbonates, which is consistent with recent studies. Tandem Mg/Ca–Δ47 results follow an exponential curve as predicted by temperature calibration equations. Observed deviations from the predicted Mg/Ca-Δ47 relationship are attributed to the effects of Fe-Mn oxide coatings, contamination, or dissolution of foraminiferal tests. This coupled approach provides a high degree of confidence in temperature estimates when Mg/Ca and Δ47 yield concordant results, and can be used to infer the past δ18O of seawater (δ18Osw) for paleoclimate studies.

Britt, B.B., Dalla Vecchia, F.M., Chure, D.J., Engelmann, G.F., Whiting, M.F., Scheetz, R.D., 2018. Caelestiventus hanseni gen. et sp. nov. extends the desert-dwelling pterosaur record back 65 million years. Nature Ecology & Evolution 2, 1386-1392.

https://doi.org/10.1038/s41559-018-0627-y

Pterosaurs are the oldest known powered flying vertebrates. Originating in the Late Triassic, they thrived to the end of the Cretaceous. Triassic pterosaurs are extraordinarily rare and all but one specimen come from marine deposits in the Alps. A new comparatively large (wing span >150 cm) pterosaur, Caelestiventus hanseni gen. et sp. nov., from Upper Triassic desert deposits of western North America preserves delicate structural and pneumatic details not previously known in early pterosaurs, and allows a reinterpretation of crushed Triassic specimens. It shows that the earliest pterosaurs were geographically widely distributed and ecologically diverse, even living in harsh desert environments. It is the only record of desert-dwelling non-pterodactyloid pterosaurs and predates all known desert pterosaurs by more than 65 Myr. A phylogenetic analysis shows it is closely allied with Dimorphodon macronyx from the Early Jurassic of Britain.

Bröker, J.N., Müller, B., van Deenen, N., Prüfer, D., Schulze Gronover, C., 2018. Upregulating the mevalonate pathway and repressing sterol synthesis in Saccharomyces cerevisiae enhances the production of triterpenes. Applied Microbiology and Biotechnology 102, 6923-6934.

https://doi.org/10.1007/s00253-018-9154-7

Pentacyclic triterpenes are diverse plant secondary metabolites derived from the mevalonate (MVA) pathway. Many of these molecules are potentially valuable, particularly as pharmaceuticals, and research has focused on their production in simpler and more amenable heterologous systems such as the yeast Saccharomyces cerevisiae. We have developed a new heterologous platform for the production of pentacyclic triterpenes in S. cerevisiae based on a combinatorial engineering strategy involving the overexpression of MVA pathway genes, the knockout of negative regulators, and the suppression of a competing pathway. Accordingly, we overexpressed S. cerevisiae ERG13, encoding 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) synthase, and a truncated and deregulated variant of the rate-limiting enzyme HMG-CoA reductase 1 (tHMGR). In the same engineering step, we deleted the ROX1 gene, encoding a negative regulator of the MVA pathway and sterol biosynthesis, resulting in a push-and-pull strategy to enhance metabolic flux through the system. In a second step, we redirected this enhanced metabolic flux from late sterol biosynthesis to the production of 2,3-oxidosqualene, the direct precursor of pentacyclic triterpenes. In yeast cells transformed with a newly isolated sequence encoding lupeol synthase from the Russian dandelion (Taraxacum koksaghyz), we increased the yield of pentacyclic triterpenes by 127-fold and detected not only high levels of lupeol but also a second valuable pentacyclic triterpene product, β-amyrin.

Brown, S.T., Basu, A., Ding, X., Christensen, J.N., DePaolo, D.J., 2018. Uranium isotope fractionation by abiotic reductive precipitation. Proceedings of the National Academy of Sciences 115, 8688-8693.


Significance: We use an experimental approach to demonstrate that 238U/235U is fractionated by abiotic reduction onto the surface of abiotic synthetic iron monosulfide, contradicting the findings of earlier studies. We further demonstrate that for abiotic reduction reactions the aqueous U speciation and removal rate control the extent of isotopic fractionation. U isotopic fractionation is observed when the primary aqueous species are Ca–UO2–CO3, suggesting that aqueous U speciation affects the relative forward and backward reaction rates and by extrapolation the relative roles of nuclear field shift effect and mass dependent kinetic fractionation.

Abstract: Significant uranium (U) isotope fractionation has been observed during abiotic reduction of aqueous U, counter to the expectation that uranium isotopes are only fractionated by bioassociated enzymatic reduction. In our experiments, aqueous U is removed from solution by reductive precipitation onto the surfaces of synthetic iron monosulfide. The magnitude of uranium isotopic fractionation increases with decreasing aqueous U removal rate and with increasing amounts of neutrally charged aqueous Ca–U–CO3 species. Our discovery means that abiotic U isotope fractionation likely occurs in any reducing environment with aqueous Ca ≥ 1 mM, and that the magnitude of isotopic fractionation changes in response to changes in aqueous major ion concentrations that affect U speciation. Our results have implications for the study of anoxia in the ancient oceans and other environments.


http://aem.asm.org/content/84/16/e01166-18.abstract

Abstract: The oxidation of Fe(II) by anoxygenic photosynthetic bacteria was likely a key contributor to Earth's biosphere prior to the evolution of oxygenic photosynthesis and is still found in a diverse range of modern environments. All known phototrophic Fe(II) oxidizers can utilize a wide range of substrates, thus making them very metabolically flexible. However, the underlying adaptations required to oxidize Fe(II), a potential stressor, are not completely understood. We used a combination of quantitative proteomics and cryogenic transmission electron microscopy (cryo-TEM) to compare cells of Rhodopseudomonas palustris TIE-1 grown photoautotrophically with Fe(II) or H2 and photoheterotrophically with acetate. We observed unique proteome profiles for each condition, with differences primarily driven by carbon source. However, these differences were not related to carbon fixation but to growth and light harvesting processes, such as pigment synthesis. Cryo-TEM showed stunted development of photosynthetic membranes in photoautotrophic cultures. Growth on Fe(II) was characterized by a response typical of iron homeostasis, which included an increased abundance of proteins required for metal efflux (particularly copper) and decreased abundance of iron import proteins, including siderophore receptors, with no evidence of further stressors, such as oxidative damage. This study suggests that the main challenge facing anoxygenic phototrophic Fe(II) oxidizers comes from growth limitations imposed by autotrophy, and, once this challenge is overcome, iron stress can be mitigated using iron management mechanisms common to diverse bacteria (e.g., by control of iron influx and efflux).

Importance: The cycling of iron between redox states leads to the precipitation and dissolution of minerals, which can in turn impact other major biogeochemical cycles, such as those of carbon, nitrogen, phosphorus and sulfur. Anoxygenic phototrophs are one of the few drivers of Fe(II) oxidation in anoxic environments and are thought to contribute significantly to iron cycling in both modern and ancient environments. These organisms thrive at high Fe(II) concentrations, yet the adaptations required to tolerate the stresses associated with this are unclear. Despite the general consensus that high Fe(II) concentrations pose numerous stresses on these organisms, our study of the large-scale proteome response of a model anoxygenic phototroph to Fe(II) oxidation demonstrates that common iron homeostasis strategies are adequate to manage this. The bulk of the proteome response is not driven by adaptations to Fe(II) stress but to adaptations required to utilize an inorganic carbon source. Such a global overview of the adaptation of these organisms to Fe(II) oxidation provides valuable insights into the physiology of these biogeochemically important organisms and suggests that Fe(II) oxidation may not pose as many challenges to anoxygenic phototrophs as previously thought.

Bücker, F., de Moura, T.M., da Cunha, M.E., de Quadros, P.D., Beker, S.A., Cazarolli, J.C., Caramão, E.B., Frazzon, A.P.G., Bento, F.M., 2018. Evaluation of the deteriogenic microbial community using qPCR, n-alkanes and FAMEs biodegradation in diesel, biodiesel and blends (B5, B10, and B50) during storage. Fuel 233, 911-917.


Understanding the changes in microbial community structure and its impact during the storage of diesel and biodiesel is critical to prevent damage to the system and to ensure a good quality product to consumers. In this study, the storage of pure diesel (B0), diesel and biodiesel blends (B5, B10, and B50), and pure biodiesel (B100) was simulated. During the simulation, and after contamination with

inoculum, microbial growth was monitored through biomass formation. Fungi and bacteria were quantified by qPCR. The effect of contamination on the biodegradation of fatty acid methyl esters (FAMEs) and n-alkanes was assessed by GC/qMS. After 60 days of incubation, B100 and B50 had the highest biomass production at the oil-water interface. Microorganism abundance was estimated by the amplification of 16S rRNA and 18S rRNA genes using qPCR. The fungal population formed at the oil-water interface was larger than the bacterial population, in all treatments. The abundance of bacteria with the alkB gene found in the blends was one or two orders of magnitude higher than that of the total bacteria estimated. The highest biodegradation rates of the C16:0, C18:0, C18:1 cis and C18:2 FAMEs (25.5, 17.5%, 34.5%, and 27.7%, respectively) occurred in the B5 blend. The highest n-alkane degradation occurred in the B50 and B10 blends. The n-alkanes C20, C18, C15, C14, and C13 had 72.1%, 57.1%, 18.5%, 21.8%, and 19.6% degradation in B50, respectively. The n-alkanes C19, C12, and C10 had 61.3%, 6.9%, and 22.97% degradation in B10, respectively. The results indicate that knowledge about the microbial contamination of fuels is important for a correct management and to reduce the associated economic losses.

Burckhardt, I., Zimmermann, S., 2018. Susceptibility testing of bacteria using MALDI-TOF mass spectrometry. Frontiers in Microbiology 9, 1744. doi: 10.3389/fmicb.2018.01744.


Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was introduced into the microbiological routine more than ten years ago. Since then is has almost replaced biochemical identification. It is unrivaled in terms of accuracy and cost. From a laboratories perspective it would be an ideal method to replace classic susceptibility testing, that is Kirby-Baur agardiffusion or determination of minimal inhibitory concentrations (MICs). First reports on possible assays for susceptibility testing are more than ten years old. However, the developments during the last five years were substantial. This review focuses with some exceptions on the progress, which was achieved during the last decade.

Burdon, D., Barnard, S., Boyes, S.J., Elliott, M., 2018. Oil and gas infrastructure decommissioning in marine protected areas: System complexity, analysis and challenges. Marine Pollution Bulletin 135, 739-758.

http://www.sciencedirect.com/science/article/pii/S0025326X18305642

Many offshore oil and gas production facilities are nearing the end of their operational life, with decommissioning now becoming a global challenge. The compatibility of decommissioning operations to marine protected areas (MPAs) creates further challenges. The recently-developed DAPSI(W)R(M) problem structuring framework (covering Drivers, Activities, Pressures, State changes, Impacts (on Welfare) and Responses (as Measures)) was applied here to interrogate the complexity of decommissioning oil and gas infrastructure within MPAs, with outputs feeding into the development of a novel database tool for Screening Potential Impacts of Decommissioning Activities (SPIDA). In meeting the current requirements of the marine regulatory regime, SPIDA provides a more streamlined, evidence-based process which can be applied by industry, statutory nature conservation bodies and regulators for identifying and evaluating evidence that supports the implications of decommissioning alternatives on the condition of MPAs. SPIDA has been developed to be adapted for other activities and sectors, including offshore renewables.

Butt, A.J., Gould, K., 2018. 3D source-rock modelling in frontier basins: a case study from the Zambezi Delta Depression. Petroleum Geoscience 24, 277-286.


Regional modelling is vital for the preliminary analysis of a basin's hydrocarbon potential, especially when working on incomplete datasets. The Zambezi Delta Depression is a frontier basin that was selected to demonstrate how limited, publically available depth data can be used to evaluate source-rock maturity and hydrocarbon expulsion using 3D basin modelling. A geological framework was built with multiple datasets correlated using a global sequence-stratigraphic model. The identification of key events in the geological history of the region and the basin geometries allowed interpretation of intervals of organic enrichment within the basin during the Bajocian, Kimmeridgian and early Aptian. The results from the pressure and temperature modelling show that these potential source-rock horizons are currently overmature to gas mature in the Zambezi Delta Depression. Using the most likely heat-flow scenario, the timing of maturity and expulsion of the potential source rocks are strongly controlled by the geometry of the basin, with ages decreasing towards the SW. Expulsion modelling suggests that the Late Cretaceous plays are most likely to be charged by the early Aptian source rock, with older potential plays charged by the Jurassic source rocks. As the heat-flow model was poorly constrained, warmer and cooler temperature scenarios were also applied to qualitatively compare the impact on maturity, expulsion and accumulation of hydrocarbons in the basin. The modelling results, when compared with sparse published data, favour the most likely and warmer scenario.

Supplementary material: Details of the model input data, source-rock definitions and software used in this project are available at https://doi.org/10.6084/m9.figshare.c.3970863

Cai, H., Stearns, S.D., 2018. A comprehensive two-dimensional gas chromatography valve modulation method using hold-release primary column flow for long secondary separation time with 100% transfer. Journal of Chromatography A 1569, 200-211.


A valve modulator with a hold-release primary column flow method has been proposed. This method uses a valve plumbed so that the head and tail of the primary column are connected during the secondary separation, to reverse, slow down, and finally stop the primary column flow. This keeps the sample in the primary column longer, gaining more time for secondary separation. Applying this method, a 60-second secondary retention time with 100% transfer, 133 ms secondary peak width at base, and no primary peak profile loss has been achieved. A standard sample with 19 compounds in 3 groups has been tested. The relative standard deviations for the retention time of this standard mixture are <0.26% for primary dimension and <0.94% for secondary dimension. A gasoline sample analysis with 5, 15, and 30-meter-long secondary columns has been demonstrated. With the secondary column length increase, the secondary separation has greatly improved even though the total run time increases to 45, 110, and 120 min and the toluene primary peak width at base increases to 0.51, 1.81, and 1.85 min respectively. A diesel samplerun by this method has also been demonstrated.

Cai, Z., Wen, H., Li, L., 2018. Clay distribution patterns regulate natural attenuation of Marcellus Shale waters in natural aquifers. Energy & Fuels.


This work examines the largely unexplored role of clay distribution patterns in determining reactive transport and natural attenuation of Marcellus Shale waters accidentally released into natural water systems (e.g., aquifers). Two heterogeneous flow cells (40 cm by 12 cm by 1 cm) were built with the same amount of clay (vermiculite) but different spatial patterns embedded in quartz. The “1/4-zone” and “1/2-zone” cells have rectangular vermiculite clusters at a quarter and a half lengths of the cells, respectively. Effluent chemistrycoming out of these cells with the same influent water compostions were compared to those in a “Uniform” column with evenly distributed vermiculite and quartz with the same vermiculite-to-quartz mass ratio. Effluent chemistry data show that spatial patterns regulate the types of dominant reactions: barium mostly precipitates as barite in the heterogeneous cells whereas primarilyexchanges onto vermiculite in the Uniform column. Spatial patterns also control the extent of reactions: the retention of trace metals (Mn, Pb, Zn, Cu, and Cd) through mineral precipitation is lowered by 1–2 orders of magnitude and presorbed Mg and K are exchanged less from the clay by 1 order of magnitude in the heterogeneous cells compared to the Uniform column. Two-dimensional reactive transport modeling reveals >90% of injected Marcellus waters flow through the higher-permeability sand zones without interacting with the clay. When ion exchange does occur, > 90% reactions occur at the quartz-clay interfaces. These findings reveals that spatial patterns can not only determine reaction rates as has been previously documented, but also regulate reaction types. This underscores the significance of spatial patterns and have important implications for predicting natural attenuation and assessing risks in naturally heterogeneous aquifer systems.

Cao, W., Xi, D., Melinte-Dobrinescu, M.C., Jiang, T., Wise, S.W., Wan, X., 2018. Calcareous nannofossil changes linked to climate deterioration during the Paleocene–Eocene thermal maximum in Tarim Basin, NW China. Geoscience Frontiers 9, 1465-1478.


The Paleocene–Eocene Thermal Maximum (PETM) event was a dramatic global warming ∼55.93 Ma ago that resulted in biological extinction events, lithological changes, and major deviations in δ13C and δ18O. The southwestern Tarim Basin of China exposes successive Paleogene strata as a result of Tethys evolution and is considered an ideal region for PETM research.

Based on calcareous nannoplankton biostratigraphy, we also used stable isotopes and XRD to analyse the Paleocene–Eocene transition in the Tarim Basin. At the Bashibulake Section, the PETM interval is characterized by (1) an abrupt negative shifts in δ13Corg, δ13Ccarb and δ18O (−3‰, −4.5‰ and −3‰ respectively); (2) an obvious negative correlation between the K-mode (Discoaster, Fasciculithus, Ericsonia, Sphenolithus and Rhomboaster) and r-mode (Biscutum, Chiasmolithus, Toweius) nannofossil taxa coincident with a robust Rhomboaster-Discoaster assemblage; and (3) a significant increase in the percentage of detrital input along with an increase in gypsum content. In the upper part of the Qimugen Formation Micrantholithus and Braarudosphaera are commonly found right up to the top where most of the nannofloras suffer a sharp decrease. In the overlying Gaijitage Formation, calcareous nannofossils disappear completely. These events indicate that the southwestern Tarim Basin was a warm shallow continental shelf during the deposition of the Qimugen Formation. From the early Eocene, the environment changed conspicuously. Evaporation increased and sea level fell, which led to an acid climate. This climate mode continued within the youngest unit studied, the Gaijitage Formation, characterized by the deposition of thick evaporates. Consequently, most of the marine plankton, i.e. calcareous nannoplankton, became disappear, because of the significant climate shift.

Cao, X., Schmidt-Rohr, K., 2018. Abundant nonprotonated aromatic and oxygen-bonded carbons make humic substances distinct from biopolymers. Environmental Science & Technology Letters 5, 476-480.

https://doi.org/10.1021/acs.estlett.8b00107

The nature of humic substances (HSs) extracted from soil organic matter and their distinction from degrading plant material has recently been called into question. Quantitative solid-state 13C nuclear magnetic resonance (NMR) analyses, in good agreement with elemental analysis, show that HSs are distinct from common biopolymers, refuting claims to the contrary made based on 1H-detected NMR spectra of the same standard peat humic acid as studied here. Aromatic carbons not bonded to hydrogen or oxygen, which are rare (≤10%) in common biomolecules, constitute a large fraction (28%–33%) of prairie soil and peat humic acids. Oxygen-bonded nonprotonated carbons such as aryl ketones, nonprotonated alkyl C–O, and abundant COOH groups are also characteristic of humic and fulvic acids but not observed in plant biopolymers. These distinctive structural differences between HSs and biopolymers challenge the recent proposal that HSs are unremarkable intermediates in a continuum of degrading biomolecules.



Plant biomass is the primary source material for soil organic matter formation. Soil organic matter comprises the largest terrestrial pool of the global C cycle and provides critical ecosystem services. The objective of this study was to document microbially-driven molecular-level changes to the water-soluble organic matter (WSOM) fraction extracted from crop residues as it undergoes biodegradation in laboratory microcosms using ultrahigh resolution mass spectrometry. Crop residues from corn and soybean fields after harvest and a leguminous, hairy vetch green manure were the sources of the WSOM studied. The results show that, at the individual molecule-level, the biodegradation process does not follow the expected trends, i.e. that higher N and lower lignin concentrations in plant biomass should favor its decomposition compared to material with lower N and higher lignin. We also show that S- and P-containing molecules are consistently more biodegradable, as compared to N-containing molecules. In addition, the results suggest that carbohydrate molecules may be less biodegradable, and that aromatic compounds may be more biodegradable, than conventionally understood. Future studies are suggested to increase our knowledge of microbially-driven biodegradation of plant biomass. Understanding plant biomass decomposition at the molecular level is fundamental to understanding how soil organic matter forms and is stabilized. This knowledge is necessary to design management practices to preserve soil organic matter and the ecosystem services it provides.

Carter Jr., C.W., Wills, P.R., 2018. Hierarchical groove discrimination by Class I and II aminoacyl-tRNA synthetases reveals a palimpsest of the operational RNA code in the tRNA acceptor-stem bases. Nucleic Acids Research, gky600-gky600.

http://dx.doi.org/10.1093/nar/gky600

Class I and II aaRS recognition of opposite grooves was likely among the earliest determinants fixed in the tRNA acceptor stem bases. A new regression model identifies those determinants in bacterial

tRNAs. Integral coefficients relate digital dependent to independent variables with perfect agreement between observed and calculated grooves for all twenty isoaccepting tRNAs. Recognition is mediated by the Discriminator base 73, the first base pair, and base 2 of the acceptor stem. Subsets of these coefficients also identically compute grooves recognized by smaller numbers of aaRS. Thus, the model is hierarchical, suggesting that new rules were added to pre-existing ones as new amino acids joined the coding alphabet. A thermodynamic rationale for the simplest model implies that Class-dependent aaRS secondary structures exploited differential tendencies of the acceptor stem to form the hairpin observed in Class I aaRS•tRNA complexes, enabling the earliest groove discrimination. Curiously, groove recognition also depends explicitly on the identity of base 2 in a manner consistent with the middle bases of the codon table, confirming a hidden ancestry of codon-anticodon pairing in the acceptor stem. That, and the lack of correlation with anticodon bases support prior productive coding interaction of tRNA minihelices with proto-mRNA.

Cartisano, C.M., Del Vecchio, R., Bianca, M.R., Blough, N.V., 2018. Investigating the sources and structure of chromophoric dissolved organic matter (CDOM) in the North Pacific Ocean (NPO) utilizing optical spectroscopy combined with solid phase extraction and borohydride reduction. Marine Chemistry 204, 20-35.


Prior optical measurements of waters in the Equatorial Atlantic Ocean (EAO) provided evidence of a major terrestrial “humic-like” component of the CDOM that absorbed in the ultraviolet (UV) and visible and emitted across the visible, along with a marine component that primarily absorbed and emitted in the UV. Here we extend these measurements to the North Pacific Ocean (NPO) at Station Aloha (22o 45′ N, 158o 00′ W). Detailed optical measurements of both the natural waters (CDOM) and C18 organic matter extracts of these waters (C18-OM) were acquired before and after sodium borohydride (NaBH4) reduction of samples obtained throughout the water column. Optical properties of the “humic-like” component were relatively uniform with depth below ~600 m [aCDOM(350) ~ 0.08 (m−1), a*CDOM (350) ~ 0.2 (m−1 mg−1C L), SUVA254 ~ 0.55 (m−1 mg−1C L), E2:E3 ~ 10, S300–700 ~ 0.02 (nm−1), S350–400 ~ 0.012 (nm−1), SR ~1.7, F(350/450) ~ 0.009 (QSE), and ϕ360 ~ 0.026], but were significantly different in surface waters, likely due to photobleaching and biological activity [aCDOM(350) ~ 0.026 (m−1), a*CDOM (350) ~ 0.027 (m−1 mg−1C L), SUVA254 ~ 0.36 (m−1 mg−1C L), E2:E3 ~ 45, S300–700 ~ 0.03 (nm−1), S350–400 ~ 0.003 (nm−1), SR ~6.8, F(350/450) ~ 0.003 (QSE), and ϕ350 ~ 0.024]. Optical properties of the short-wavelength components (UV bands) were more variable with depth. Response to solid phase extraction was also relatively uniform with depth, with preferential extraction of the long-wavelength absorbing/emitting “humic-like” component (~30–50% extraction efficiency at λ <300 nm and ~50–80% at λ >400 nm) and virtually no extraction of the the UV absorbing/emitting bands. Response to NaBH4 reduction was also similar down the water column with preferential loss of absorption in the visible region, and enhanced, blue-shifted fluorescence emission.

As in the EAO the ‘humic-like” component exhibited very similar, although not identical, optical and chemical properties to those observed for terrestrially-dominated estuarine and coastal environments, providing evidence that this component originates from a terrestrial source. Although this component dominated the absorption, marine contributions (i.e. UV bands) similar to those observed in the EAO were also observed. However, these components were found to absorb and emit primarily in the UV and were not efficiently extracted by the C18 columns, clearly showing that they are structurally distinct from the “humic-like” component.

Casey, J.A., Wilcox, H.C., Hirsch, A.G., Pollak, J., Schwartz, B.S., 2018. Associations of unconventional natural gas development with depression symptoms and disordered sleep in Pennsylvania. Scientific Reports 8, Article 11375.

https://doi.org/10.1038/s41598-018-29747-2

Environmental and community factors may influence the development or course of depression and sleep problems. We evaluated the association of unconventional natural gas development (UNGD) with depression symptoms and disordered sleep diagnoses using the Patient Health Questionnaire-8 and electronic health record data among Geisinger adult primary care patients in Pennsylvania. Participants received a retrospective metric for UNGD at their residence (very low, low, medium, and high) that incorporated dates and durations of well development, distance from patient homes to wells, and well characteristics. Analyses included 4,762 participants with no (62%), mild (23%), moderate (10%), and moderately severe or severe (5%) depression symptoms in 2014–2015 and 3,868 disordered sleep diagnoses between 2009–2015. We observed associations between living closer to more and bigger wells and depression symptoms, but not disordered sleep diagnoses in models weighted to account for sampling design and participation. High UNGD (vs. very low) was associated with depression symptoms in an adjusted negative binomial model (exponentiated coefficient = 1.18, 95% confidence interval [CI]: 1.04–1.34). High and low UNGD (vs. very low) were associated with depression symptoms (vs. none) in an adjusted multinomial logistic model. Our findings suggest that UNGD may be associated with adverse mental health in Pennsylvania.

Cavan, E.L., Giering, S.L.C., Wolff, G.A., Trimmer, M., Sanders, R., 2018. Alternative particle formation pathways in the Eastern Tropical North Pacific's biological carbon pump. Journal of Geophysical Research: Biogeosciences 123, 2198-2211.

https://doi.org/10.1029/2018JG004392

Abstract: A fraction of organic carbon produced in the oceans by phytoplankton sinks storing 5–15 gigatonnes of carbon annually in the ocean interior. The accepted paradigm is that rapid aggregation of phytoplankton cells occurs, forming large, fresh particles which sink quickly; this concept is incorporated into ecosystem models used to predict the future climate. Here we demonstrate a slower, less efficient export pathway in the Eastern Tropical North Pacific. Lipid biomarkers suggest that the large, fast‐sinking particles found beneath the mixed layer are compositionally distinct from those found in the mixed layer and thus not directly and efficiently formed from phytoplankton cells. We postulate that they are formed from the in situ aggregation of smaller, slow‐sinking particles over time in the mixed layer itself. This export pathway is likely widespread where smaller phytoplankton species dominate. Its lack of representation in biogeochemical models suggests that they may be currently overestimating the ability of the oceans to store carbon if large, fast‐sinking, labile particles dominate simulated particle export.

Plain Language Summary: The oceans are one of the largest sinks of atmospheric carbon dioxide on our planet. One method by which this occurs is through the production of organic material (phytoplankton—plant‐like cells) in the surface ocean, which capture atmospheric carbon dioxide during photosynthesis. Eventually, the phytoplankton die and sink out of the surface ocean, transporting huge amounts of carbon to the deep ocean where it is stored for centuries or even millennia. Our current understanding is that generally, most organic material sinks quickly as large, fast‐sinking (hundreds of meters per day) particles (clumps of dead phytoplankton cells). However, in our study in the Equatorial Pacific Ocean, we were able to show that a different and much slower process occurs where phytoplankton first aggregate to smaller, slower sinking detrital particles and eventually form very degraded larger particles that sink to the deep. This has consequences for

estimating ocean carbon storage as smaller particles are respired much quicker than larger particles. Thus, where they are an important part of this carbon sink, such as in the Equatorial Pacific, the proportion phytoplankton‐captured atmospheric carbon dioxide being stored in the deep ocean is likely reduced.



Heavy crude oil processing leads the way in current refining. These crudes yield larger amounts of distillable heavy fractions such as vacuum gas oil (VGO). VGO must be treated in at least two refining units: a hydrotreating unit where sulfur, nitrogen, and other heteroatoms are removed, and a hydrocracking unit where suitable fuels are obtained. Removal of heteroatoms during hydrotreating, particularly, nitrogen, dictates the efficiency of hydrocracking. In the first part of this work, the nature of refractory nitrogen-containing compounds on the performance of a hydrotreating catalyst was evaluated. To achieve this goal, both a VGO and its hydrotreated counterpart were studied using electrospray ionization with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR-MS). Weakly basic N-containing compounds, namely, heavy pyrrolic-like compounds and their partially hydrogenated derivatives, were found to be the most refractory to hydrotreating. These compounds are weakly basic compared to most nitrogen compounds present in VGO. Considering this finding, the second part of the work was devoted to assessing the effect of pyrroles on the reactivity of phenanthrene over a Ni–MoS2/Y-zeolite–alumina two-stage hydrocracking catalyst. Tests were carried out in a fixed-bed reactor using mixtures of carbazole and tetrahydrocarbazole. Results showed that these compounds can affect the catalytic performance of Ni–MoS2/Y-zeolite–alumina by reducing its activity and inhibiting its selectivity to hydrocracking products. These findings draw attention to the possible role of weakly basic nitrogen compounds in the catalytic performance of materials employed for two-stage hydrocracking units.

Celma, A., Bijlsma, L., López, F.J., Sancho, J.V., 2018. Development of a Retention Time Interpolation scale (RTi) for liquid chromatography coupled to mass spectrometry in both positive and negative ionization modes. Journal of Chromatography A 1568, 101-107.


The accuracy and sensitivity of high resolution mass spectrometry (HRMS) enables the identification of candidate compounds with the use of mass spectrometric databases among other tools. However, retention time (RT) data in identification workflows has been sparingly used since it could be strongly affected by matrix or chromatographic performance. Retention Time Interpolation scaling (RTi) strategies can provide a more robust and valuable information than RT, gaining more confidence in the identification of candidate compounds in comparison to an analytical standard. Up to our knowledge, no RTi has been developed for LC-HRMS systems providing information when acquiring in either positive or negative ionization modes.

In this work, an RTi strategy was developed by means of the use of 16 isotopically labelled reference standards, which can be spiked into a real sample without resulting in possible false positives or negatives. For testing the RTi performance, a mixture of several reference standards, emulating suspect analytes, were used. RTi values for these compounds were calculated both in solvent and

spiked in a real matrix to assess the effect of either chromatographic parameters or matrix in different scenarios. It has been demonstrated that the variation of injection volume, chromatographic gradient and initial percentage of organic solvent injected does not considerably affect RTi calculation. Column aging and solid support of the stationary phase of the column, however, showed strong effects on the elution of several test compounds. Yet, RTi permitted the correction of elution shifts of most compounds. Furthermore, RTi was tested in 47 different matrices from food, biological, animal feeding and environmental origin. The application of RTi in both positive and negative ionization modes showed in general satisfactory results for most matrices studied.

The RTi developed can be used in future LC-HRMS screening analysis giving an additional parameter, which facilitates tedious processing tasks and gain more confidence in the identification of (non)-suspect analytes.

Chaleckis, R., Meister, I., Zhang, P., Wheelock, C.E., 2019. Challenges, progress and promises of metabolite annotation for LC–MS-based metabolomics. Current Opinion in Biotechnology 55, 44-50.


Accurate annotation is vital for data interpretation; however, metabolite identification is a major bottleneck in untargeted metabolomics. Although community guidelines for metabolite identification were published over a decade ago, adaptation of the recommended standards has been limited. The complexity of LC–MS data due to combinations of various chromatographic and mass spectrometric acquisition methods has resulted in the advent of diverse workflows, which often involve non-standardized manual curation. Herein, we review the parameters involved in metabolite reporting and provide a workflow to estimate the level of confidence in reported metabolite annotation. The future of metabolite identification will be heavily based upon the use of metabolome data repositories and associated data analysis tools, which will enable data to be shared, re-analyzed and re-annotated in an automated fashion.

Chao, Y., Gao, S., Wang, X., Li, N., Zhao, H., Wen, X., Lou, Z., Dong, X., 2018. Untargeted lipidomics based on UPLC-QTOF-MS/MS and structural characterization reveals dramatic compositional changes in serum and renal lipids in mice with glyoxylate-induced nephrolithiasis. Journal of Chromatography B 1095, 258-266.


Nephrolithiasis is a systemic metabolic disease with a worldwide incidence that is increasing yearly, as well as a high recurrence rate; however, this disease's pathogenesis has not been thoroughly elucidated to date. Several epidemiological studies have shown that the risk for developing kidney stones increases in people with dyslipidemia. To explore the mechanism of lipid-induced kidney stones, we established a mouse model for renal urolithiasis based on intraperitoneal injections of glyoxylate (120 mg/kg/d). Lipidomics based on ultra high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS/MS) was performed to determine the changes in lipid metabolism in serum and kidneys. We screened 179 and 196 different lipid metabolites in the kidneys and serum, respectively, including fatty acyls, glycerophospholipids, sphingolipids, glycerolipids and prenol lipids. We found that polyunsaturated fatty acids, such as arachidonic acid, eicosapentaenoic acid, and docosahexoenoic acid, and ceramides and lysophosphocholines mediated inflammatory responses and that the oxidative stress induced by oleylethanolamine and glycerophosphoethanolamine plasmalogens is closely related to the development of kidney stones. These results provide strong evidence for the relationship between

lipid metabolism and the development of kidney stones and suggest a clear direction for future research.

Cheah, Y.E., Young, J.D., 2018. Isotopically nonstationary metabolic flux analysis (INST-MFA): putting theory into practice. Current Opinion in Biotechnology 54, 80-87.


Typically, 13C flux analysis relies on assumptions of both metabolic and isotopic steady state. If metabolism is steady but isotope labeling is not allowed to fully equilibrate, isotopically nonstationary metabolic flux analysis (INST-MFA) can be used to estimate fluxes. This requires solution of differential equations that describe the time-dependent labeling of network metabolites, while iteratively adjusting the flux and pool size parameters to match the transient labeling measurements. INST-MFA holds a number of unique advantages over approaches that rely solely upon steady-state isotope enrichments. First, INST-MFA can be applied to estimate fluxes in autotrophic systems, which consume only single-carbon substrates. Second, INST-MFA is ideally suited to systems that label slowly due to the presence of large intermediate pools or pathway bottlenecks. Finally, INST-MFA provides increased measurement sensitivity to estimate reversible exchange fluxes and metabolite pool sizes, which represents a potential framework for integrating metabolomic analysis with 13C flux analysis. This review highlights the unique capabilities of INST-MFA, describes newly available software tools that automate INST-MFA calculations, presents several practical examples of recent INST-MFA applications, and discusses the technical challenges that lie ahead.


https://doi.org/10.1021/acs.est.8b01583

Dichloromethane (DCM) is a probable human carcinogen and frequent groundwater contaminant and contributes to stratospheric ozone layer depletion. DCM is degraded by aerobes harboring glutathione-dependent DCM dehalogenases; however, DCM contamination occurs in oxygen-deprived environments, and much less is known about anaerobic DCM metabolism. Some members of the Peptococcaceae family convert DCM to environmentally benign products including acetate, formate, hydrogen (H2), and inorganic chloride under strictly anoxic conditions. The current study applied stable carbon and chlorine isotope fractionation measurements to the axenic culture Dehalobacterium formicoaceticum and to the consortium RM comprising DCM degrader Candidatus Dichloromethanomonas elyunquensis. Degradation-associated carbon and chlorine isotope enrichment factors (εC and εCl) of −42.4 ± 0.7‰ and −5.3 ± 0.1‰, respectively, were measured in D. formicoaceticum cultures. A similar εCl of −5.2 ± 0.1‰, but a substantially lower εC of −18.3 ± 0.2‰, were determined for Ca. Dichloromethanomonas elyunquensis. The εC and εCl values resulted in distinctly different dual element C–Cl isotope correlations (ΛC/Cl = Δδ13C/Δδ37Cl) of 7.89 ± 0.12 and 3.40 ± 0.03 for D. formicoaceticum and Ca. Dichloromethanomonas elyunquensis, respectively. The distinct ΛC/Cl values obtained for the two cultures imply mechanistically distinct C–Cl bond cleavage reactions, suggesting that members of Peptococcaceae employ different pathways to metabolize DCM. These findings emphasize the utility of dual carbon–chlorine isotope analysis to pinpoint DCM degradation mechanisms and to provide an additional line of evidence that detoxification is occurring at DCM-contaminated sites.

Chen, J., Chen, D., Zhang, X., Wang, M., Chen, B., An, D., Xu, L., Lyu, Q., 2018. Quantification of alcohols, diols and glycerol in fermentation with an instantaneous derivatization using trichloroacetyl isocyanante via liquid chromatography-mass spectrometry. Journal of Chromatography A 1568, 22-28.


A sensitive LC–MS/MS method was established to quantify diols and glycerol in fermentation broth using trichloroacetyl isocyanate as instantaneous derivatization reagent for monitoring the production of 1,3-propanediol and 2,3-butanediol from the biodiesel biorefinery process. Due to the derivatization reaction was very quickly at room temperature, only 1 min was needed for the reaction process. In addition, both extraction of analytes and evaporation of water were not employed in the analytical procedure. Furthermore, the isotope of chlorine was beneficial for understanding of the secondary mass spectrum and avoiding false positive results. Therefore, much more accurate results of diols and glycerol concentration in fermentation could be obtained even at very low levels for the evaluation of microbial metabolism pathway modification.

Chen, L., Jiang, Z., Liu, K., Gao, F., 2017. Quantitative characterization of micropore structure for organic-rich Lower Silurian shale in the Upper Yangtze Platform, South China: Implications for shale gas adsorption capacity. Advances in Geo-Energy Research 1, 112-123.

http://www.astp-agr.com/index.php/Index/Index/detail?id=26

The pores in shales are mainly of nanometer-scale, and their pore size distribution is very important for shale gas storage and adsorption capacity, especially micropores having widths less than 2 nm, which contribute to the main occurrence space for gas adsorption. This study is focused on the organic-rich Lower Silurian black shale from four wells in the Upper Yangtze Platform, and their total organic carbon (TOC), mineralogical composition and micropore characterization were investigated. Low pressure CO2 adsorption measurement was conducted at 273.15 K in the relative pressure range of 0.0001-0.03, and the micropore structure was characterized by Dubinin-Radushkevich (DR) equation and density functional theory (DFT) method and then the relationship between micropore structure and shale gas adsorption capacity was discussed. The results indicated that (1) The Lower Silurian shale have high TOC content in the range of 0.92-4.96%, high quartz content in the range of 30.6-69.5%, and high clays content in the range of 24.1-51.2%. The TOC content shows a strong positive relationship with the quartz content which suggests that the quartz is mainly biogenic in origin. (2) The micropore volume varies from 0.12 cm3/100 g to 0.44 cm3/100 g and micropore surface area varies from 4.97 m2/g to 17.94 m2/g. Both of them increase with increasing TOC content, indicating TOC is the key factor to control the micropore structure of the Lower Silurian shale. (3) Low pressure CO2 adsorption measurement provides the most suitable detection range (0.3-1.5 nm) and has high reliability and accuracy for micropore structure characterization. (4) The TOC content is the key factor to control gas adsorption capacity of the Lower Silurian shale in the Upper Yangtze Platform.

Chen, R., Qin, Y., Zhang, P., Wang, Y., 2018. Changes in pore structure of coal caused by CS2 treatment and its methane adsorption response. Geofluids 2018, Article 7578967.

https://doi.org/10.1155/2018/7578967

The pore structure and gas adsorption are two key issues that affect the coal bed methane recovery process significantly. To change pore structure and gas adsorption, 5 coals with different ranks were treated by CS2 for 3 h using a Soxhlet extractor under ultrasonic oscillation conditions; the evolutions of pore structure and methane adsorption were examined using a high-pressure mercury intrusion porosimeter (MIP) with an AutoPore IV 9310 series mercury instrument. The results show that the cumulative pore volume and specific surface area (SSA) were increased after CS2 treatment, and the incremental micropore volume and SSA were increased and decreased before and after Ro,max =1.3%, respectively; the incremental big pore (greater than 10 nm in diameter) volumes were increased and SSA was decreased for all coals, and pore connectivity was improved. Methane adsorption capacity on coal before and after Ro,max =1.3% also was increased and decreased, respectively. There is a positive correlation between the changes in the micropore SSA and the Langmuir volume. It confirms that the changes in pore structure and methane adsorption capacity due to CS2 treatment are controlled by the rank, and the change in methane adsorption is impacted by the change of micropore SSA and suggests that the changes in pore structure are better for gas migration; the alteration in methane adsorption capacity is worse and better for methane recovery before and after . A conceptual mechanism of pore structure is proposed to explain methane adsorption capacity on CS2 treated coal around the Ro,max =1.3%.

Chen, S., Tang, D., Tao, S., Chen, Z., Xu, H., Li, S., 2018. Coal reservoir heterogeneity in multicoal seams of the Panguan Syncline, western Guizhou, China: Implication for the development of superposed CBM-bearing systems. Energy & Fuels 32, 8241-8253.


The reservoir heterogeneity of multiple coal seams in the Panguan area was systematically analyzed based on coalmine geological exploration data, field-test data, and laboratory tests. The results show that the physical properties (e.g., pore size distribution) of adjacent coal seams in the same well are basically the same due to the similar coal rank and the nonexistence of a coalification jump, whereas the ash yield and sulfur content related to the sedimentary environment exhibit a “high–low–high” trend with increasing depth. After the third coalification jump, coal becomes much more compact with a reduction in the seepage space and increase in the specific surface area. Additionally, the NMR T2 spectrum decreases from a bimodal to a unimodal curve. The reservoir temperature (15–50 °C) increases linearly with depth, but the influence of temperature on the CH4 adsorption capacity is insignificant in this area. Additionally, the well test parameters reveal that the pressure systems are vertically superposed due to the well water resistance of the key stratigraphic units. Specifically, the reservoir pressure tends to increase with depth in the same pressure system, and a corresponding increase in gas content is observed. An abrupt point of the pressure coefficient can be regarded as a boundary of different gas-bearing systems. At the end of a gas-bearing system, coal seams are characterized by supersaturated reservoirs with a gas saturation >100%. Furthermore, the change rule of coal permeability is more complex in multiple coal seams due to the existence of superposed pressure systems. In the same stress field, a higher coal permeability is observed due to the higher reservoir pressure. In general, the reservoir pressure and in situ stress distribution are the two main determinants of the coalbed methane (CBM) enrichment and development in multicoal seams, which should be paid more attention in the selection of favorable target layers.



Unconventional oil and gas (UOG) extraction, also known as hydraulic fracturing, is becoming more prevalent with the increasing use and demand for natural gas; however, the full extent of its environmental impacts is still unknown. Here we measured physicochemical properties and bacterial community composition of sediment samples taken from twenty-eight streams within the Marcellus Shale formation in northeastern Pennsylvania differentially impacted by hydraulic fracturing activities. Fourteen of the streams were classified as UOG+, and thirteen were classified as UOG- based on the presence of unconventional oil and gas extraction in their respective watersheds. One stream was located in a watershed that previously had unconventional oil and gas extraction activities but was recently abandoned. We utilized high-throughput sequencing of the 16S rRNA gene to infer differences in sediment aquatic bacterial community structure between UOG+ and UOG- streams, as well as correlate bacterial community structure to physicochemical water parameters. Although overall alpha and beta diversity differences were not observed, there were a plethora of significantly enriched operational taxonomic units (OTUs) within UOG+ and UOG- samples. Our biomarker analysis revealed many of the bacterial taxa enriched in UOG+ streams can live in saline conditions, such as Rubrobacteraceae. In addition, several bacterial taxa capable of hydrocarbon degradation were also enriched in UOG+ samples, including Oceanospirillaceae. Methanotrophic taxa, such as Methylococcales, were significantly enriched as well. Several taxa that were identified as enriched in these samples were enriched in samples taken from different streams in 2014; moreover, PLS-DA revealed clustering between streams from the different studies based on the presence of hydraulic fracturing along the second axis. This study revealed significant differences between bacterial assemblages within stream sediments of UOG+ and UOG- streams and identified several potential biomarkers for evaluating and monitoring the response of autochthonous bacterial communities to potential hydraulic fracturing impacts.



Three potential source rock intervals were evaluated based on the results of Rock-Eval pyrolysis on nearly 700 rock samples and the origin of the twenty-two oil-fields was studied by the biomarker analysis on 62 source rock samples and 93 oil samples in the Raoyang Sag and Baxian Sag, Bohai Bay Basin. The first member of the Shahejie Formation (Es) was deposited in an anoxic and salted water column with the dominant contribution of algal organic matters, reflected by its rock samples with high gammacerane/C30-hopane, high ETR, high C35/C34 hopane, high steranes/hopanes, low pristane/phytane, low C27-diasterane/C27-sterane and low C19/C23 tricyclic terpane. Characterized by higher C19/C23 tricyclic terpane, higher pristane/phytane, lower steranes/hopanes and lower C35/C34 hopane than the Es1 rock samples, the biomarkers of rocks suggest that the third and forth members of the Es were deposited in the sub-oxic to anoxic environments with a significant terrestrial organism input. Further studies suggest that the best source rock interval for oil-generation is the Es1 source rock interval in the Raoyang Sag and is the Es3 source rock interval in the Baxian Sag by organic facies analysis of source rocks.

Three source-related oil groups have been identified. There are two oil groups for the discovered oils in the Raoyang Sag. Group I oil, dominated by the Es1-derived oils, has been found in all the oil-fields in the Raoyang Sag, and Group II oil, mainly derived from the Es3 source rock interval, only distributes in the north-east area and in the south end of the Raoyang Sag. However, the three oil groups have been found in the Baxian Sag, but the Es3-derived oils are dominant in them and have

been found in the major oil-fields in the east area and the Wen'an slope in the west area. Furthermore, the Es4-derived oils (Group III oil) mainly distribute in the Baxian Sag, without any findings in the Raoyang Sag because of the absence of the Es4 source rocks. As our studies, oils almost accumulate near their source rocks without a long-distance migration except the slope areas in the Raoyang Sag and Baxian Sag. Therefore, the source rock distribution is a key factor to oil accumulations in the Raoyang Sag and Baxian Sag, especially the efficient source rock distributions, which mainly developed in the organic facies A and B based on the geochemical and geological researches.


https://doi.org/10.1306/0926171423117184

Because clay minerals and pore-size distribution are important for oil and gas accumulation in lacustrine mudstone reservoirs, this study aimed to characterize the pore-size distribution in lacustrine mudstone, reveal the importance of clay minerals in gas sorption capacity (GSC), provide insights into the primary GSC controls for lacustrine mudstones, and discuss the shale oil and gas resource potential and possible risks in their future production. A total of 256 core samples from the lower Paleogene sequence of the Dongying depression in the Bohai Bay Basin in China were analyzed to determine organic richness and hydrocarbon generation potential. A series of analyses was conducted on a suite of 28 mudstone samples from the S121 well to investigate the mineral composition, pore-size distribution, and primary controls on GSC. Scanning electron microscopy and x-ray diffraction were used to observe the microscopic characteristics and identify various minerals. Nitrogen adsorption experiments at low temperatures and a methane isothermal adsorption test were conducted to study the pore sizes and gas adsorption capacities. Experimental results show that the majority of the samples were rich in type II and I kerogen with moderate to high hydrocarbon generation potential and are thermally mature in the main oil window. The contents of illite and mixed layer illite–smectite (I–S) are high (>40%) in these lacustrine mudstones. The pores were mainly thin, long, and bottleneck shaped and dominated by type IV and H2 hysteresis loop characteristics. The abundance of quartz, feldspar, illite, and mixed layer I–S all presented a positive correlation with their Brunauer–Emmett–Teller surface area and total pore volume, whereas the abundance of carbonate minerals (dominated by calcite) showed a negative correlation. The volume of micropores and clay minerals were the main factors controlling GSCs. The results highlight the importance of clay minerals, including the illite and mixed layer I–S, in the lacustrine mudstones because of their considerable GSC. High content of illite and mixed layer I–S in lacustrine mudstone is in favor of gas storage, whereas at the same time, it is not conducive to shale gas development because of its reducing the brittleness of shale. The Paleogene of Dongying depression has shale oil and gas resources; however, several key geological factors, including pore-size distributions, pore diameters, oil density, and low brittleness, may pose risks in shale oil and gas development.



Carbon isotopes of inorganic carbon-bearing materials (gaseous CO2, dissolved inorganic carbon (DIC) and solid carbonates) sampled from four mud volcanoes in the northern Tianshan fold zone were investigated to study the mud volcanic carbon cycling process. The analysed carbon isotopes showed 13C enriched characteristics, the δ13C values of CO2, DIC and solid carbonates were in the range of 10.99–32.11‰, 17.02–36.22‰, and −7.28–12.40‰, respectively. The 13C enrichment of CO2 could be attributed to carbon isotope fractionation during the partial reduction of CO2 by methanogenic bacteria. The positive δ13C values in DIC may be caused by the carbon isotope fractionation during CO2-water-rock interactions. The mixture of carbonate precipitates from DIC in the water and carbonate minerals from the host rock resulted in a relatively less positive δ13C value in carbonates of the mud samples. The reduction of CO2 by methanogenic bacteria could be the primary mechanism for the 13C enrichment of inorganic carbon during the carbon cycling process in the mud volcanic systems in the northern Tianshan fold zone.



Hydrocarbons with an Ediacaran–Early Cambrian origin from the central Sichuan Basin, South China were investigated for biomarker compositions. They were obtained by solvent extraction from the Upper Ediacaran reservoir core samples, which contain abundant solid bitumen. The solid bitumen is widely believed to be formed by thermal cracking of early-charged oils in the reservoirs, which have presumed source rocks of an Ediacaran–Early Cambrian age. Thermal maturity parameters based on phenanthrenes and aromatic steroids suggest a very high thermal maturity for the extracted hydrocarbons, which is consistent with the severe maturation undergone by their host reservoirs. Age-diagnostic biomarkers including C30 24-isopropylcholestanes and mid-chain monomethyl alkanes support source rocks of an Ediacaran–Early Cambrian age. The extracted hydrocarbons have very similar biomarker signatures, which include high relative abundance of acyclic isoprenoids and pristane/phytane <1; high abundance of 2α-methylhopanes; high abundance of C27 to C29 steranes with a slight preference for either C27 or C29 homologues; high relative abundance of diasteranes; the concomitant presence of 24-n-propyl and 24-isopropylcholestanes and 24-isopropyl/24-n-propylcholestanes > 1; and the presence of C26 norcholestanes, methyl- and ethylsteranes. The presence of hopanoids including extended series and methylhopanes indicates contributions from prokaryotic bacteria while the presence of various steroids including regular steranes and methylsteranes indicates contributions from the eukaryotic algae. Parameters based on tricyclic terpane and hopane, dibenzothiophene/phenanthrene ratios, and C27 diasteranes/(diasteranes + regular steranes) ratios suggest a major shale source, but a mixed shale-carbonate source cannot be completely excluded. Presence of C30 demethylsteranes, low pristane/phytane ratios, high gammacerane index, and presence of 28,30-dinorhopane and 2-methyhopanes indicate that the source rocks were deposited in a stratified, anoxic marine depositional environment with enhanced salinity conditions.

Cheng, Q., 2018. Extrapolations of secular trends in magmatic intensity and mantle cooling: Implications for future evolution of plate tectonics. Gondwana Research 63, 268-273.


The beginning of plate tectonics on Earth remains the subject of fundamental debate. Also, future evolution of plate tectonics has not yet been addressed adequately in the literature. Here I develop

models to extrapolate secular trends of plate tectonics closely associated with mantle potential temperature; intensity of magmatic activities to estimate the lifetime of plate tectonics. First a fractal model is utilized to analyze global igneous and detrital zircon U-Pb age datasets to characterize nonlinear intensity and periodicity of peaks in magmatic activities associated with deep-seated avalanche-type events (slab break off, lithospheric root detachments and mantle plumes). The results show descending trends of both nonlinear intensity and duration of peaks in magmatism observed from 3 Ga to the present day, suggesting a general trend of mantle cooling. This relation when extrapolated yields 1.45 Gyr of time for when nonlinear intensity of major magmatic activity would vanish. Further it is demonstrated by an independent polynomial model fitted to the relation between mantle potential temperature and future age of the earth that this result conforms to the time estimated for when mantle potential temperature is reduced to mantle solidus temperature.

Clarke, H., Turner, P., Bustin, R.M., Riley, N., Besly, B., 2018. Shale gas resources of the Bowland Basin, NW England: a holistic study. Petroleum Geoscience 24, 287-322.


New data from three shale gas exploration wells in the Bowland Basin of NW England contribute to the understanding of the stratigraphy, tectonic history and unconventional hydrocarbon resource potential of Lower Carboniferous strata. Three main prospective shales dominate the identified unconventional reservoirs: the Upper Bowland and Lower Bowland shales and the Hodder Mudstone, which are recognized by their distinctive lithology, corresponding log signatures and key zonal ammonoids. With a combined thickness of over 5000 ft (c. 1500 m), this sequence of shales is one of thickest known potential self-sourced, unconventional hydrocarbon resources. The strata are organic rich with total organic carbon (TOC) values of between 1 and 7%, with an average of 2.65%, and organic maturity that ranges from the upper oil window (pyrolysis Tmax c. 450°C) in the higher part of the section to dry gas (Ro = 2.4%; pyrolysis Tmax >470°C) in the Lower Bowland Shale. The sequence is strongly heterolithic, and up to 60% free gas is stored in thinly bedded carbonate and clastic silty turbidites. Adsorbed gas is concentrated in more organic-rich, hemipelagic shales which are distributed throughout the sequence. Near maximum burial temperatures of c. 130°C are inferred from vitrinite reflectance (Ro) and are consistent with fluid-inclusion microthermometry of carbonate-filled fractures. This indicates oil generation in the Late Carboniferous, prior to Variscan uplift. Renewed subsidence through the early Mesozoic resulted in increased maturity and gas generation. In the Bowland Shale the gas per unit volume of rock ranges from about 0.6 to 1.5 Bcf (billion cubic ft) per metre per square mile. The thick interval of gas-charged strata provides the opportunity to exploit these major hydrocarbon resources by using stacked multilateral wells from a common, strategically located and environmentally optimized surface pad.

Comyn-Platt, E., Hayman, G., Huntingford, C., Chadburn, S.E., Burke, E.J., Harper, A.B., Collins, W.J., Webber, C.P., Powell, T., Cox, P.M., Gedney, N., Sitch, S., 2018. Carbon budgets for 1.5 and 2 °C targets lowered by natural wetland and permafrost feedbacks. Nature Geoscience 11, 568-573.

https://doi.org/10.1038/s41561-018-0174-9

Global methane emissions from natural wetlands and carbon release from permafrost thaw have a positive feedback on climate, yet are not represented in most state-of-the-art climate models. Furthermore, a fraction of the thawed permafrost carbon is released as methane, enhancing the combined feedback strength. We present simulations with an inverted intermediate complexity climate model, which follows prescribed global warming pathways to stabilization at 1.5 or 2.0 °C above pre-industrial levels by the year 2100, and which incorporates a state-of-the-art global land

surface model with updated descriptions of wetland and permafrost carbon release. We demonstrate that the climate feedbacks from those two processes are substantial. Specifically, permissible anthropogenic fossil fuel CO2 emission budgets are reduced by 17–23% (47–56 GtC) for stabilization at 1.5 °C, and 9–13% (52–57 GtC) for 2.0 °C stabilization. In our simulations these feedback processes respond more quickly at temperatures below 1.5 °C, and the differences between the 1.5 and 2 °C targets are disproportionately small. This key finding holds for transient emission pathways to 2100 and does not account for longer-term implications of these feedback processes. We conclude that natural feedback processes from wetlands and permafrost must be considered in assessments of transient emission pathways to limit global warming.

Cordero-Lanzac, T., Palos, R., Hita, I., Arandes, J.M., Rodríguez-Mirasol, J., Cordero, T., Bilbao, J., Castaño, P., 2018. Revealing the pathways of catalyst deactivation by coke during the hydrodeoxygenation of raw bio-oil. Applied Catalysis B: Environmental 239, 513-524.


Virtually all processes aiming fuels and chemicals from biomass entail no less than one step for removing oxygen by hydrodeoxygenation (HDO). The bottleneck of HDO is the formation of deactivating-carbonaceous species on the catalyst surface. In this work, we have studied the deactivation pathways of catalysts based on noble metal nanoparticles (Pt-Pd) supported on mildly acid supports during the HDO of raw bio-oil. At conditions of accelerated deactivation, monitoring the evolution with time on stream of hydrocarbon and oxygenated compounds in the reaction medium, the intermediates on the catalyst surface and the nature-location of deactivating species, two parallel deactivation routes have been revealed: the deposition of (i) thermal or pyrolytic lignin from alkyl(methoxy) phenols, on the catalyst mesopores and favored at low temperature, and; of (ii) aromatic coke from polycyclic aromatic hydrocarbons, starting on the catalyst micropores through condensation reactions and promoted by acidic sites and high temperature. Nevertheless, catalyst deactivation can be controlled within limits at harsh temperature conditions (450 °C) due to the preferential HDO of alkyl(methoxy) phenols into aromatics and the formation-hydrocracking steady state of the aromatic precursors of coke.

Cousins, C.R., Fogel, M., Bowden, R., Crawford, I., Boyce, A., Cockell, C., Gunn, M., 2018. Biogeochemical probing of microbial communities in a basalt-hosted hot spring at Kverkfjöll volcano, Iceland. Geobiology 16, 507-521.


We investigated bacterial and archaeal communities along an ice‐fed surficial hot spring at Kverkfjöll volcano—a partially ice‐covered basaltic volcano at Vatnajökull glacier, Iceland, using biomolecular (16S rRNA, apsA, mcrA, amoA, nifH genes) and stable isotope techniques. The hot spring environment is characterized by high temperatures and low dissolved oxygen concentrations at the source (68°C and <1 mg/L (±0.1%)) changing to lower temperatures and higher dissolved oxygen downstream (34.7°C and 5.9 mg/L), with sulfate the dominant anion (225 mg/L at the source). Sediments are comprised of detrital basalt, low‐temperature alteration phases and pyrite, with <0.4 wt. % total organic carbon (TOC). 16S rRNA gene profiles reveal that organisms affiliated with Hydrogenobaculum (54%–87% bacterial population) and Thermoproteales (35%–63% archaeal population) dominate the micro‐oxic hot spring source, while sulfur‐oxidizing archaea (Sulfolobales, 57%–82%), and putative sulfur‐oxidizing and heterotrophic bacterial groups dominate oxic downstream environments. The δ13Corg (‰ V‐PDB) values for sediment TOC and microbial biomass range from −9.4‰ at the spring's source decreasing to −12.6‰ downstream. A reverse effect isotope

fractionation of ~3‰ between sediment sulfide (δ34S ~0‰) and dissolved water sulfate (δ34S +3.2‰), and δ18O values of ~ −5.3‰ suggest pyrite forms abiogenically from volcanic sulfide, followed by abiogenic and microbial oxidation. These environments represent an unexplored surficial geothermal environment analogous to transient volcanogenic habitats during putative “snowball Earth” scenarios and volcano–ice geothermal environments on Mars.

Cózar, A., Morillo-García, S., Ortega, M.J., Li, Q.P., Bartual, A., 2018. Macroecological patterns of the phytoplankton production of polyunsaturated aldehydes. Scientific Reports 8, Article 12282.

https://doi.org/10.1038/s41598-018-29787-8

The polyunsaturated aldehydes (PUAs) are bioactive metabolites commonly released by phytoplankton species. Based primarily on laboratory experiments, PUAs have been implicated in deleterious effects on herbivores and competing phytoplankton species or in the regulation of the rates of bacterial organic matter remineralization; however, the role of the PUAs at an ecosystem level is still under discussion. Using data of PUA production in natural phytoplankton assemblages over a wide range of conditions, we analyzed macroecological patterns aiming for a comprehensive environmental contextualization that will further our understanding of the control and ecologic role played by these compounds. PUA composition changed from the predominance of decadienal in oligotrophy, octadienal in eutrophy, and heptadienal at intermediate conditions. The production of PUAs per unit biomass also showed a strong relationship with the trophic status, sharply increasing towards oligotrophic conditions and with small-sized cells reaching the highest production rates. High ratios of dissolved inorganic nitrogen to dissolved inorganic phosphorus also promoted PUA production, albeit to a considerably lesser extent. Although the allelopathic use of PUAs to outcompete other phytoplankton or reduce herbivory may be key in some environments and interactions, the macroecological patterns found here, showing higher production towards the poorest waters and among the small species typically populating these environments, support and link at the large scale the hypotheses of the nutrient-derived stress as driver for the production of PUAs together with the use of these compounds as boosters for the nutrient remineralization.

Crowe, S.A., Cox, R.P., Jones, C., Fowle, D.A., Santibañez-Bustos, J.F., Ulloa, O., Canfield, D.E., 2018. Decrypting the sulfur cycle in oceanic oxygen minimum zones. The ISME Journal 12, 2322-2329.

https://doi.org/10.1038/s41396-018-0149-2

Here we present ecophysiological studies of the anaerobic sulfide oxidizers considered critical to cryptic sulfur cycling in oceanic oxygen minimum zones (OMZs). We find that HS− oxidation rates by microorganisms in the Chilean OMZ offshore from Dichato are sufficiently rapid (18 nM h−1), even at HS− concentrations well below 100 nM, to oxidize all sulfide produced during sulfate reduction in OMZs. Even at 100 nM, HS− is well below published half-saturation concentrations and we conclude that the sulfide-oxidizing bacteria in OMZs (likely the SUP05/ARTIC96BD lineage of the gammaproteobacteria) have high-affinity (>105 g−1 wet cells h−1) sulfur uptake systems. These specific affinities for sulfide are higher than those recorded for any other organism on any other substrate. Such high affinities likely allow anaerobic sulfide oxidizers to maintain vanishingly low sulfide concentrations in OMZs driving marine cryptic sulfur cycling. If more broadly distributed, such high-affinity sulfur biochemistry could facilitate sulfide-based metabolisms and prominent S-cycles in many other ostensibly sulfide-free environments.

Cruz Luque, M.M., Urban-Rascon, E., Aguilera, R.F., Aguilera, R., 2018. Mexican unconventional plays: Geoscience, endowment, and economic considerations. SPE Reservoir Evaluation & Engineering 21, 533-549.

https://doi.org/10.2118/189438-PA

Summary Successful activities in the Eagle Ford Shale in Texas through drilling of horizontal wells and completions by use of multistage-hydraulic-fracturing jobs suggest that the potential of shale reservoirs farther south will be quite significant. This observation leads to the objective of this paper: to examine geoscience and engineering data of tight and shale reservoirs in Mexico with a view to estimating the oil and gas endowment, and to determine the economics of developing these plays under current and forecast possible oil and gas prices. Plays considered in this study include the Burgos, Sabinas, Tampico, Tuxpan (Platform), Veracruz, and Chihuahua Basins. Endowment is defined by the US Geological Survey (USGS) (USGS 2000) as the sum of known volumes of oil and gas (cumulative production plus remaining reserves) and undiscovered volumes. The economics of these plays is examined with the use of cumulative long-run supply (or availability) curves. These are presented as crossplots of production costs per barrel of oil or per Mcf of gas vs. endowments for the aggregate of basins, and are very useful to demonstrate how endowment volumes vary at different price levels. It is concluded that the potential of unconventional resources in Mexico is quite significant and will help to change the slope of production rates in the country from negative to positive. As a result, it is anticipated that Mexico will become an important part of the shale-petroleum revolution started in the US.

Cui, C., Zhang, L., Ma, Y., Billa, T., Hou, Z., Shi, Q., Zhao, S., Xu, C., Klein, M.T., 2018. Computer-aided gasoline compositional model development based on GC-FID analysis. Energy & Fuels 32, 8366-8373.


The demand for improved gasoline product quality has helped make molecular-level models become more preferred for the modern refinery. Building the molecular compositional model is an essential first step for this quantitative molecular management of gasoline streams. Gas chromatography equipped with flame ion detection (GC-FID) is commonly used in the gasoline detailed hydrocarbon analysis (DHA). The combination of GC-FID analysis and molecular-level modeling is thus very attractive. In the present study, we developed a gasoline compositional model based solely on GC-FID as input. To suppress the negative influence of peak coelution, we developed a statistics-based peak tuning algorithm to obtain individual compound resolution at higher carbon number range. Using the tuned result as input, the molecular-level gasoline compositional model was built by estimating the quantitative percentages of the species in a predefined molecular library (573 molecules). The molecular-level compositional model has good extensibility and can link to the molecule-based physical properties prediction model. The model has been verified via applications on various gasoline samples. The prediction of research octane number for large-scale gasoline samples was also revealed.

Cui, L., Dubos, F., Bourrel, M., 2018. Novel alkyl-amine surfactants for CO2 emulsion assisted enhanced oil recovery. Energy & Fuels 32, 8220-8229.


Novel CO2-soluble surfactants are designed for generating stable CO2 emulsion/foam at high temperature (110 °C) and high salinity (220 g/L NaCl). The novel surfactants only consist of alkyl chains and amine heads without any fluorine, silicon, or poly alkyl-oxide groups and outperform the surfactants in literature regarding the solubility, thermal stability, and emulsifying ability in harsh conditions. 0.2 wt % of the novel surfactants are soluble in 220 g/L NaCl brine at pH ≤ 8 from 20 to 120 °C and are soluble in CO2 at high temperature (110 °C) and relatively low pressure (91 bar). The surfactants are thermally stable at 110 °C and pH = 4 under anaerobic conditions. Strong CO2 emulsion can be readily generated in bulk and in porous media at 25–110 °C and 150 bar. Unlike the common surfactants in literature, the performance of the novel surfactants can be profoundly enhanced by salinity and temperature. The strategy for designing these novel molecules and tuning the surfactant formulation for emulsion-assisted CO2 enhanced oil recovery (EOR) is discussed as well.

Cui, X., Yang, E., Song, K., Wang, Y., 2018. The seepage model considering liquid/solid interaction in confined nanoscale pores. Geofluids 2018, Article 8302782.

https://doi.org/10.1155/2018/8302782

Different from conventional reservoirs, nanoscale pores and fractures are dominant in tight or shale reservoirs. The flow behaviors of hydrocarbons in nanopores (called “confined space”) are more complex than that of bulk spaces. The interaction between liquid hydrocarbons and solid pore wall cannot be neglected. The viscosity formula which is varied with the pore diameter and interaction coefficient of liquids and solids in confined nanopores has been introduced in this paper to describe the interaction effects of hydrocarbons and pore walls. Based on the Navier-Stokes equation, the governing equation considered liquid/solid effect in two dimensions has been established, and approximate theoretical solutions to the governing equations have been achieved after mathematic simplification. By introducing the vortex equation, the complex numerical seepage model has been discretized and solved. Numerical results show that the radial velocity distribution near the solid wall has an obvious change when considering the liquid/solid interaction. The results consist well with that approximate mathematical solution. And when the capillary radius is smaller, the liquid and solid interaction coefficient is greater. The liquid and solid interaction obviously cannot be neglected in the seepage model if the capillary radius is small than 50 nm when n > 0.1. The numerical model has also been further validated by two types of nanopore flow tests: from pore to throat and inversely from throat to pore. There is no big difference in flow regularity of throat to pore model considering when liquid/solid interaction or not, whereas the liquid/solid interaction of pore to throat model totally cannot be overlooked.

Dal Corso, J., Gianolla, P., Rigo, M., Franceschi, M., Roghi, G., Mietto, P., Manfrin, S., Raucsik, B., Budai, T., Jenkyns, H.C., Reymond, C.E., Caggiati, M., Gattolin, G., Breda, A., Merico, A., Preto, N., 2018. Multiple negative carbon-isotope excursions during the Carnian Pluvial Episode (Late Triassic). Earth-Science Reviews 185, 732-750.


The Carnian Pluvial Episode was a phase of global climatic change and biotic turnover that occurred during the early Late Triassic. In marine sedimentary basins, the arrival of huge amounts of siliciclastic sediments, the establishment of anoxic conditions, and a sudden change of the carbonate factory on platforms marked the Carnian Pluvial Episode. The sedimentary changes are closely associated with abrupt biological turnover among marine and terrestrial groups as, for example, an extinction among ammonoids and conodonts in the ocean, and a turnover of the vertebrate fauna and

the flora on land. Multiple negative carbon-isotope excursions were recorded during the Carnian Pluvial Episode in both organic matter and marine carbonates, suggesting repeated injection of 13C-depleted CO2 into the ocean–atmosphere system, but their temporal and causal links with the sedimentological and palaeontological changes are poorly understood. We here review the existing carbon-isotope records and present new data on the carbon-isotope composition of organic carbon in selected sections of the western Tethys realm that record the entire Carnian Pluvial Episode. New ammonoid, conodont and sporomorph biostratigraphic data were collected and coupled to an extensive review of the existing biostratigraphy to constrain the age of the sampled sections. The results provide biostratigraphically constrained composite organic carbon-isotope curves for the Carnian, which sheds light on the temporal and causal links between the main carbon-isotope perturbations, and the distinct environmental and biotic changes that mark the Carnian Pluvial Episode. The carbon-isotope records suggest that a series of carbon-cycle perturbations, possibly recording multiple phases of volcanic activity during the emplacement of the Wrangellia Large Igneous Province, disrupted Carnian environments and ecosystems repeatedly over a remarkably long time interval of about 1 million years.

Darroch, S.A.F., Smith, E.F., Laflamme, M., Erwin, D.H., 2018. Ediacaran extinction and Cambrian explosion. Trends in Ecology & Evolution 33, 653-663.


The Ediacaran–Cambrian (E–C) transition marks the most important geobiological revolution of the past billion years, including the Earth’s first crisis of macroscopic eukaryotic life, and its most spectacular evolutionary diversification. Here, we describe competing models for late Ediacaran extinction, summarize evidence for these models, and outline key questions which will drive research on this interval. We argue that the paleontological data suggest two pulses of extinction – one at the White Sea–Nama transition, which ushers in a recognizably metazoan fauna (the ‘Wormworld’), and a second pulse at the E–C boundary itself. We argue that this latest Ediacaran fauna has more in common with the Cambrian than the earlier Ediacaran, and thus may represent the earliest phase of the Cambrian Explosion.

Davidson, L.M., Arthur, T.J., Smith, G.F., Tubb, S., 2018. Geology and hydrocarbon potential of offshore SE Somalia. Petroleum Geoscience 24, 247-257.


Interpretation of a 20 550 line km 2D seismic survey acquired in 2014 by Soma Oil and Gas in the deep water offshore area of SE Somalia has identified three previously undocumented sedimentary provinces – Jubba Deep, Mogadishu Deep and Mid Somalia High – all of which have distinctive geological characteristics. Well and stratigraphic controls are limited, with inferred lithologies largely based on seismic stratigraphic interpretation.

The Jubba Deep has a thick Late Cretaceous–Early Tertiary deltaic section deformed by major gravitational collapses in the Paleocene-age Kismaayo Thrust Belt (KTB) and the Pliocene-age Baraawe Thrust Belt (BTB). It is proposed that the KTB has significant hydrocarbon potential in deltaic and pro-delta sands trapped in thrust anticlines and sourced with oil from Mid-Cretaceous mobile shales.

The Mogadishu Deep Basin has a thick Mesozoic and Tertiary section but is missing the thick deltaics seen in the Jubba Basin. Volcanics are present in this basin.

The Mid Somalia High has a relatively thinner sedimentary section where Cretaceous and Jurassic reservoirs and potential source rocks are at moderate burial depths. An extensive post-rift Mid–Late Jurassic carbonate platform is developed here with potential hydrocarbon targets in interpreted reefs and shoal facies.

Supplementary material: Additional seismic examples and map figures are available at https://doi.org/10.6084/m9.figshare.c.3902650

Davies, H.S., Green, J.A.M., Duarte, J.C., 2018. Back to the future: Testing different scenarios for the next supercontinent gathering. Global and Planetary Change 169, 133-144.


The theory of plate tectonics and the discovery of large scale, deep-time cycles, such as the Supercontinent cycle and Wilson cycle, has contributed to the identification of several supercontinents in Earth's history. Using the rules of plate tectonic theory, and the dynamics of subduction zones and mantle convection, it is possible to envisage scenarios for the formation of the next supercontinent, which is believed to occur around 200–300 Ma into the future. Here, we explore the four main proposed scenarios for the formation of the next supercontinent by constructing them, using GPlates, in a novel and standardised way. Each scenario undergoes different modes of Wilson and Supercontinent cycles (i.e., introversion, extroversion, orthoversion, and combination), illustrating that the relationship between them is not trivial and suggesting that these modes should be treated as end-members of a spectrum of possibilities. While modelling the future has limitations and assumptions, the construction of the four future supercontinents here has led to new insights into the mechanisms behind Wilson and Supercontinent cycles. For example, their relationship can be complex (in terms of being of the same or different order, or being in or out of phase with each other) and the different ways they can interact may led to different outcomes of large-scale mantle reorganization. This work, when combined with geodynamical reconstructions since the Mesozoic allows the simulation of the entire present-day Supercontinent cycle and the respectively involved Wilson cycles. This work has the potential to be used as the background for a number of studies, it was just recently used in tidal modelling experiments to test the existence of a Supertidal cycle associated with the Supercontinent cycle.

Davudov, D., Moghanloo, R.G., 2019. A new model for permeability impairment due to asphaltene deposition. Fuel 235, 239-248.


The existing theoretical and empirical models to describe asphaltene deposition in porous media do not consider the complicated structure of pore network. Permeability reduction due to asphaltene deposition has been mainly attributed to pore volume shrinkage (porosity reduction). However, asphaltene particles can also block pore throats which will lead to severe permeability reduction even when a large fraction of total pore volume still remains intact. Thus, there is a need for permeability models that are explicitly function of pore/hydraulic connectivity. This paper provides a review of the existing models and examines a permeability model that explain permeability impairment due to asphaltene deposition.

In this study, we propose a new permeability model based on Critical Path Analysis (CPA) which is a function of average coordination number (average number of available/connected neighbor pores). Furthermore, experimental data in the literature related to limestone, sandstone and carbonate

(dolomite) samples are utilized to understand combined effects of surface deposition and interconnectivity loss due to pore blockage on permeability reduction.

We observed that surface deposition is the dominant mechanism in the limestone samples studied here owing to large pore throat size compared to the particle size. In the sandstone samples, both the surface deposition and pore throat plugging mechanisms contribute fairly the same in the observed permeability reduction. For the carbonate (dolomite) samples, the pore blockage is the dominant mechanism, which results in rapid sharp decrease of the permeability. It is expected that the outcome of this work improves prediction of the asphaltene deposition in the near wellbore region.

de Bar, M.W., Stolwijk, D.J., McManus, J.F., Sinninghe Damsté, J.S., Schouten, S., 2018. A Late Quaternary climate record based on long chain diol proxies from the Chilean margin. Climate of the Past Discussions 2108, 1-34.

https://doi.org/10.5194/cp-2018-88

The primary focus of this study is to test the applicability of different paleoenvironmental proxies based on long chain diols, i.e., the LDI as proxy for past SST, the Diol Index as indicator of past upwelling conditions and the NDI as quantitative proxy for nitrate and phosphate concentrations in seawater. The proxies were analyzed in marine sediments recovered at ODP Site 1234, located within the Peru-Chile upwelling system, with a ~2kyr resolution, covering the last 150kyrs, i.e., encompassing several glacial and interglacial periods. We also generated TEXH86 and UK´37

temperature and planktonic δ18O records, as well as TOC and accumulation rates (ARs) of TOC and lipid biomarkers (i.e., C37 alkenones, GDGTs, dinosterol and loliolide) to reconstruct past phytoplankton production. The LDI-derived SST record co-varies with TEXH86 and UK´37 -derived SST records as well as with the planktonic δ18O record, implying that the LDI reflects past SST variations at this site. TOC and phytoplankton AR records indicate increased export production during the Last Interglacial (MIS 5), simultaneous with a peak in the abundance of preserved Chaetoceros diatoms, suggesting intensified upwelling during this period. The Diol Index is relatively low during the upwelling period, but peaks before and after this period, suggesting that Proboscia diatoms were more dominant before and after the period of upwelling. The NDI reveals the same variations as the Diol Index suggesting that the input of nitrate and phosphate was minimal during upwelling, which is unrealistic. We suggest that the Diol Index should perhaps be considered as an indicator for Proboscia (multiple species) productivity instead of upwelling per se, whereas the NDI likely reflects Proboscia alata productivity, and might therefore not be suitable as a more general paleonutrient proxy.

De Falco, N., Boano, F., Bogler, A., Bar-Zeev, E., Arnon, S., 2018. Influence of stream-subsurface exchange flux and bacterial biofilms on oxygen consumption under nutrient-rich conditions. Journal of Geophysical Research: Biogeosciences 123, 2021-2034.

https://doi.org/10.1029/2017JG004372

Abstract The lack of a complete understanding of the complex reciprocal interactions between hydrological processes and the structure and function of microbial communities limits our ability to improve the predictions of microbial metabolism in streams. We report here on how overlying water velocity and losing and gaining flux interact with bacterial community structure and its activity to control oxygen consumption in a sandy streambed under high nutrient levels. We used an experimental flume packed with natural sediment and measured the bacterial biomass distribution and oxygen profiles in the streambed and across bed forms. Local oxygen consumption rates were calculated with a 1-D numerical model (GRADIENT). Bacterial abundance and production rates

varied across the bed form within 1 order of magnitude, while their taxonomic classes were similar across bed forms despite variations in flow conditions and sediment disturbance events. However, bacterial production rates were not directly correlated with bacterial abundance. On the other hand, oxygen consumption rates ranged over 4 orders of magnitude across the bed forms and were highly correlated with the vertical exchange flux between the water and the streambed. The results strongly suggest that under high nutrient levels, the system is, in general, transport limited and that predicting oxygen consumption rates depends on local vertical exchange fluxes.


https://doi.org/10.1002/mas.21551

The identification of unknown molecules has been one of the cornerstone applications of mass spectrometry for decades. This tutorial reviews the basics of the interpretation of electrospray ionization‐based MS and MS/MS spectra in order to identify small‐molecule analytes (typically below 2000 Da). Most of what is discussed in this tutorial also applies to other atmospheric pressure ionization methods like atmospheric pressure chemical/photoionization. We focus primarily on the fundamental steps of MS‐based structural elucidation of individual unknown compounds, rather than describing strategies for large‐scale identification in complex samples. We critically discuss topics like the detection of protonated and deprotonated ions ([M + H]+ and [M − H]−) as well as other adduct ions, the determination of the molecular formula, and provide some basic rules on the interpretation of product ion spectra. Our tutorial focuses primarily on the fundamental steps of MS‐based structural elucidation of individual unknown compounds (eg, contaminants in chemical production, pharmacological alteration of drugs), rather than describing strategies for large‐scale identification in complex samples. This tutorial also discusses strategies to obtain useful orthogonal information (UV/Vis, H/D exchange, chemical derivatization, etc) and offers an overview of the different informatics tools and approaches that can be used for structural elucidation of small molecules. It is primarily intended for beginning mass spectrometrists and researchers from other mass spectrometry sub‐disciplines that want to get acquainted with structural elucidation are interested in some practical tips and tricks.

Delamaide, E., 2018. Senlac, the forgotten SAGD project. SPE Reservoir Evaluation & Engineering 21, 789-805.

https://doi.org/10.2118/183721-PA

The Senlac steam-assisted-gravity-drainage (SAGD) project in Saskatchewan, Canada, does not have the same name recognition as its much bigger brothers in the Alberta Oil Sands, but it certainly deserves to be known better. Senlac was the first industrial SAGD project in Canada, back in 1997, and since then, it has been the site for other technological innovations such as the use of solvent in addition with steam to increase recovery and reduce the steam/oil ratio (SOR), as well as the testing of wedge wells—wells drilled between SAGD well pairs to benefit from the heat remaining in the reservoir. The reservoir in Senlac is the Dina-Cummings of the Lower Cretaceous, and is much smaller than the McMurray formation, the site of most large-scale oil-sands projects, but the oil is only 5,000 cp; thus, it is mobile at reservoir temperature. This is a significant difference that allows well pairs to achieve excellent production and recovery even though reservoir thickness is only 8 to 16m, well below the standard cutoff for SAGD. The presence of bottomwater under parts of the field is an added challenge to the operations. The paper will present the field characteristics and production

performances as well as the main technological developments such as the solvent-added process (SAP) and the use of wedge wells. The paper will present a complete case study of an SAGD project in a heavy-oil reservoir where oil is mobile. Most SAGD projects so far have been conducted in bitumen, but the paper will show the potential for this technology in thinner and smaller reservoirs.

Delarue, F., Robert, F., Sugitani, K., Tartèse, R., Duhamel, R., Derenne, S., 2018. Nitrogen isotope signatures of microfossils suggest aerobic metabolism 3.0 Gyr ago. Geochemical Perspectives Letters 7, 32-36.

http://www.geochemicalperspectivesletters.org/article1816

There is compelling evidence for early oxygenation of mid-Archean oceans. However, the biological use of molecular oxygen is still not ascertained. Here we report the nitrogen isotope composition measured in isolated microfossils (δ15Nµm) from the 3.0 billion years old Farrel Quartzite metasediments. We show that the quasi-null bulk δ15N values of Farrel Quartzite organic matter encompass a large 15N isotopic heterogeneity at the scale of isolated microfossils (-21.6 ‰ < δ15Nµm < +30.7 ‰). Rayleigh fractionation is required to yield such large δ15N variations. Based on these data, we propose a model in which negative δ15Nµm values determined on film-like and on spheroidal microfossils are explained by ammonia assimilation in the anoxic deeper levels of the water column, whereas positive δ15Nµm values determined on lenticular microfossils were driven by both ammonia assimilation and aerobic oxidation close to the sea surface. Since ammonium aerobic oxidation requires the presence of free molecular O2 within the water column, we further suggest that positive δ15Nµm values reflect an ocean redox stratification tightly related to O2 production by oxygenic photosynthesisers in a mid-Archean ocean 3.0 Gyr ago.

Dellinger, M., West, A.J., Paris, G., Adkins, J.F., Pogge von Strandmann, P.A.E., Ullmann, C.V., Eagle, R.A., Freitas, P., Bagard, M.-L., Ries, J.B., Corsetti, F.A., Perez-Huerta, A., Kampf, A.R., 2018. The Li isotope composition of marine biogenic carbonates: Patterns and mechanisms. Geochimica et Cosmochimica Acta 236, 315-335.


Little is known about the fractionation of Li isotopes during formation of biogenic carbonates, which form the most promising geological archives of past seawater composition. Here we investigated the Li isotope composition (δ7Li) and Li/Ca ratios of organisms that are abundant in the Phanerozoic record: mollusks (mostly bivalves), echinoderms, and brachiopods. The measured samples include (i) modern calcite and aragonite shells from various species and natural environments (13 mollusk samples, 5 brachiopods and 3 echinoderms), and (ii) shells from mollusks grown under controlled conditions at various temperatures. When possible, the mollusk shell ultrastructure was micro-sampled in order to assess intra-shell heterogeneity. In this paper, we systematically characterize the influence of mineralogy, temperature, and biological processes on the δ7Li and Li/Ca of these shells and compare with published data for other taxa (foraminifera and corals).

Aragonitic mollusks have the lowest δ7Li, ranging from +16 to +22‰, echinoderms have constant δ7Li of about +24‰, brachiopods have δ7Li of +25 to +28‰, and finally calcitic mollusks have the largest range and highest δ7Li values, ranging from +25‰ to +40‰. Measured brachiopods have similar δ7Li compared to inorganic calcite precipitated from seawater (δ7Li of +27 to +29‰), indicating minimum influence of vital effects, as also observed for other isotope systems and making them a potentially viable proxy of past seawater composition. Calcitic mollusks, on the contrary, are not a good archive for seawater paleo–δ7Li because many samples have significantly higher δ7Li

values than inorganic calcite and display large inter-species variability, which suggests large vital effects. In addition, we observe very large intra-shell variability, in particular for mixed calcite-aragonite shells (over 20‰ variability), but also in mono-mineralic shells (up to 12‰ variability). Aragonitic bivalves have less variable δ7Li (7‰ variability) compared to calcitic mollusks, but with significantly lower δ7Li compared to inorganic aragonite, indicating the existence of vital effects. Bivalves grown at various temperatures show that temperature has only a minor influence on fractionation of Li isotopes during shell precipitation. Interestingly, we observe a strong correlation (R2 = 0.83) between the Li/Mg ratio in bivalve Mytilus edulis and temperature, with potential implications for paleo-temperature reconstructions.

Finally, we observe a negative correlation between the δ7Li and both the Li/Ca and Mg/Ca ratio of calcite mollusks, which we relate to biomineralization processes. To explain this correlation, we propose preferential removal of 6Li from the calcification site of calcite mollusks by physiological processes corresponding to the regulation of the amount of Mg in the calcifying medium. We calculate that up to 80% of the initial Li within the calcification site is removed by this process, leading to high δ7Li and low Li/Ca in some calcite mollusk specimens. Collectively, these results suggest that Mg (and thus [Li]) is strongly biologically controlled within the calcifying medium of calcite mollusks.

Overall, the results of this study show that brachiopods are likely to be suitable targets for future work on the determination of paleo-seawater Li isotope composition—an emerging proxy for past weathering and hydrothermal processes.



Recent advances in nanotechnology have opened a lot of new possibilities for nanomaterials application in wide variety of industrial, pharmaceutical, medicinal and environmental applications. This review aims to description of various Fourier Transform Infrared (FTIR)-based spectroscopic techniques suitable to characterize (i) different types of nanomaterials and (ii) various macroscopic samples at their nanoscale. In the introductory section, nanomaterials are classified according to their crucial properties, i.e. chemical composition, size and surface morphology. Application of traditional FTIR techniques, such as Attenuated Total Reflection (ATR), Diffuse Reflection (DRIFT) and infrared micro (spectro)scopy, for characterization of nanomaterials and nanostructures is compared with novel optical nanoscopic techniques derived from scanning probe microscopy which enable to overcome the diffraction limit and to characterize nanomaterials at molecular scale.



Lignite is difficult to degrade, thus stimulation of the autochthonous lignite microflora and introduction of additional microorganisms are required for lignite decomposition. Here, a packed bed reactor, filled with lignite samples from the Konin region (central Poland) was supplied continuously with M9 medium, supplemented with molasses (a by-product from the sugar industry), for 124 days

to stimulate the autochthonous lignite microflora. Acidic fermentation of molasses was observed in the bioreactor. The simultaneous decomposition of lignite occurred under this acidic molasses fermentation condition. Our results show decay of free (non-bound) organic compounds during anaerobic lignite biodegradation. The concentrations of n-alkanes, n-alkanols, n-alkanoic acids, diterpenoids, triterpenoids and steroids present in non-biodegraded samples decreased significantly (some compounds to zero) during biodegradation. Interestingly, other compound classes like phenols, ketones and certain organic compounds increased. We interpret this phenomenon as a gradual decomposition of polymers, lignin and cellulose, present in the lignite. These changes resulted from microbial activity since they were not observed in pure solutions of short-chain fatty acids. The 16SrRNA profiling of the microbial community selected in the bioreactor revealed that the dominant bacteria belonged to the Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes, furthermore representatives of 16 other phyla were also found. All the known taxa of lignocellulolytic bacteria were represented in the microbial community. Synergistic relations between bacteria fermenting molasses and bacteria degrading lignite are assumed. The results confirm lignin degradation in acidic medium by bacteria under anaerobic conditions.


https://doi.org/10.1038/s41561-018-0168-7

Quantifying soil carbon dynamics is of utmost relevance in the context of global change because soils play an important role in land–atmosphere gas exchange. Our current understanding of both present and future carbon dynamics is limited because we fail to accurately represent soil processes across temporal and spatial scales, partly because of the paucity of data on the relative importance and hierarchical relationships between microbial, geochemical and climatic controls. Here, using observations from a 3,000-kyr-old soil chronosequence preserved in alluvial terrace deposits of the Merced River, California, we show how soil carbon dynamics are driven by the relationship between short-term biotic responses and long-term mineral weathering. We link temperature sensitivity of heterotrophic respiration to biogeochemical soil properties through their relationship with microbial activity and community composition. We found that soil mineralogy, and in particular changes in mineral reactivity and resulting nutrient availability, impacts the response of heterotrophic soil respiration to warming by altering carbon inputs, carbon stabilization, microbial community composition and extracellular enzyme activity. We demonstrate that biogeochemical alteration of the soil matrix (and not short-term warming) controls the composition of microbial communities and strategies to metabolize nutrients. More specifically, weathering first increases and then reduces nutrient availability and retention, as well as the potential of soils to stabilize carbon.

dos Santos Rodrigues, C.C., Santos, L.G.G.V., Santos, E., Damasceno, F.C., Corrêa, J.A.M., 2018. Polycyclic aromatic hydrocarbons in sediments of the Amazon River Estuary (Amapá, Northern Brazil): Distribution, sources and potential ecological risk. Marine Pollution Bulletin 135, 769-775.


The distribution, sources and potential ecological risk of priority polycyclic aromatic hydrocarbons (PAHs) in sediment from the Amazon River Estuary (Macapá and Santana, Amapá, Northern Brazil) were investigated. The total PAHs concentration (∑PAH) ranged from 22.2 to 158.9 ng g−1 dw (mean value 49.4 ng g−1 dw). PAHs levels in the study area were relatively low than those in nearby areas

and other coastal zones worldwide, and could be considered as baseline for PAHs in Amazonic sediments. PAHs ratios and the statistical analysis showed that fossil fuel and biomass combustions, primarily from local sources, were the dominant PAHs origins. The potential ecological risk was assessed on the basis of the sediment quality guidelines, and it was found that PAHs in the sediments of the Amazon River Estuary do not cause adverse effects on living organisms; however, the abundance of naphthalene and the presence of dibenzo[a,h]anthracene and benzo[a]pyrene deserve more attention.

Doss, W., Marchitto, T.M., Eagle, R., Rashid, H., Tripati, A., 2018. Deconvolving the saturation state and temperature controls on benthic foraminiferal Li/Ca, based on downcore paired B/Ca measurements and coretop compilation. Geochimica et Cosmochimica Acta 236, 297-314.


Li/Ca in calcitic benthic foraminiferal tests has been suggested to co-vary with both temperature and carbonate chemistry, but these two influences have been difficult to disentangle. We use several new downcore records of Li/Ca in Cibicidoides wuellerstorfi and Uvigerina, paired with the carbonate proxy B/Ca, to further elucidate this behavior. We also combine the downcore measurements with a compilation of coretop Li/Ca data. Uvigerina B/Ca presumably records pore water saturation with respect to calcite (ΔCO3

2−), though downcore data show that it partially reflects bottom water ΔCO32−

(inferred from C. wuellerstorfi B/Ca), with a relationship that is consistent with a previous global coretop calibration. Downcore Li/Ca is significantly correlated to B/Ca in both taxa, implying a positive relationship between Li/Ca and carbonate chemistry. This connection breaks down in the coretop compilation however, likely due to the confounding influence of temperature on Li/Ca. We attempt to isolate the temperature influence using a negative exponential equation previously derived from abiotic calcite precipitation experiments, and introduce a new quantity ΔLi/Ca, which is the observed departure from the temperature-based prediction. This transformation brings the downcore and coretop Li/Ca measurements into alignment, with up to 90% of the ΔLi/Ca variance explained by ΔCO3

2−. Finally, we perform preliminary tests of Li/Ca as a paleo-proxy for both ΔCO32− and

temperature.

Dragoš, A., Lakshmanan, N., Martin, M., Horváth, B., Maróti, G., Falcón García, C., Lieleg, O., Kovács, Á.T., 2018. Evolution of exploitative interactions during diversification in Bacillus subtilis biofilms. FEMS Microbiology Ecology 94, Article fix155.

http://dx.doi.org/10.1093/femsec/fix155

Microbial biofilms are tightly packed, heterogeneous structures that serve as arenas for social interactions. Studies on Gram negative models reveal that during evolution in structured environments like biofilms, isogenic populations commonly diversify into phenotypically and genetically distinct variants. These variants can settle in alternative biofilm niches and develop new types of interactions that greatly influence population productivity. Here, we explore the evolutionary diversification of pellicle biofilms of the Gram positive, spore-forming bacterium Bacillus subtilis. We discovered that—similarly to other species—B. subtilis diversifies into distinct colony variants. These variants dramatically differ in biofilm formation abilities and expression of biofilm-related genes. In addition, using a quantitative approach, we reveal striking differences in surface complexity and hydrophobicity of the evolved colony types. Interestingly, one of the morphotypes completely lost the ability of independent biofilm formation and evolved to hitchhike with other morphotypes with improved biofilm forming abilities. Genome comparison suggests that major phenotypic transformations between the morphotypes can be triggered by subtle genetic differences. Our work

demonstrates how positive complementarity effects and exploitative interactions intertwine during evolutionary diversification in biofilms.



In the deep biosphere, microbial sulfate reduction (MSR) is exploited for energy. Here, we show that, in fractured continental crystalline bedrock in three areas in Sweden, this process produced sulfide that reacted with iron to form pyrite extremely enriched in 34S relative to 32S. As documented by secondary ion mass spectrometry (SIMS) microanalyses, the δ34Spyrite values are up to +132‰V‐CDT and with a total range of 186‰. The lightest δ34Spyrite values (−54‰) suggest very large fractionation during MSR from an initial sulfate with δ34S values (δ34Ssulfate,0) of +14 to +28‰. Fractionation of this magnitude requires a slow MSR rate, a feature we attribute to nutrient and electron donor shortage as well as initial sulfate abundance. The superheavy δ34Spyrite values were produced by Rayleigh fractionation effects in a diminishing sulfate pool. Large volumes of pyrite with superheavy values (+120 ± 15‰) within single fracture intercepts in the boreholes, associated heavy average values up to +75‰ and heavy minimum δ34Spyrite values, suggest isolation of significant amounts of isotopically light sulfide in other parts of the fracture system. Large fracture‐specific δ34Spyrite variability and overall average δ34Spyrite values (+11 to +16‰) lower than the anticipated δ34Ssulfate,0 support this hypothesis. The superheavy pyrite found locally in the borehole intercepts thus represents a late stage in a much larger fracture system undergoing Rayleigh fractionation. Microscale Rb–Sr dating and U/Th–He dating of cogenetic minerals reveal that most pyrite formed in the early Paleozoic era, but crystal overgrowths may be significantly younger. The δ13C values in cogenetic calcite suggest that the superheavy δ34Spyrite values are related to organotrophic MSR, in contrast to findings from marine sediments where superheavy pyrite has been proposed to be linked to anaerobic oxidation of methane. The findings provide new insights into MSR‐related S‐isotope systematics, particularly regarding formation of large fractions of 34S‐rich pyrite.

Drouin, N., Pezzatti, J., Gagnebin, Y., González-Ruiz, V., Schappler, J., Rudaz, S., 2018. Effective mobility as a robust criterion for compound annotation and identification in metabolomics: Toward a mobility-based library. Analytica Chimica Acta 1032, 178-187.


Capillary electrophoresis (CE) presents many advantageous features as an analytical technique in metabolomics, such as very low consumption of a sample or the possibility to easily detect very polar and ionizable compounds. However, CE remains an approach only used by a few research groups due to a relatively lower sensitivity and, higher analysis time compared to liquid chromatography. To circumvent these drawbacks, herein we propose a generic CE–mass spectrometry (MS) approach using positive electrospray ionization mode and performing normal- and reverse-polarity CE separations to analyze anionic and acidic compounds. Preliminary experiments showed better sensitivity using the ESI positive mode compared to the ESI negative mode on a set of representative anionic compounds from different biochemical families. This approach was applied to the investigation of an available library of metabolites. More than 450 compounds out of the 596 in the library were detected, with the possibility to monitor negatively ionizable compounds through their ammonium adducts. Migration time of each data point was converted to an effective mobility (μeff) scale and used for peak alignment in data pre-processing; μeff features were used as a robust

migration index for peak annotation and identification criterion. For the first time, a large database based on experimental μeff was built, allowing for the straightforward annotation of detected features in biological samples and demonstrating how CE-MS can complement other analytical techniques commonly used in metabolomics.

Du, Z., Zhang, X., Luan, Z., Wang, M., Xi, S., Li, L., Wang, B., Cao, L., Lian, C., Li, C., Yan, J., 2018. In situ Raman quantitative detection of the cold seep vents and fluids in the chemosynthetic communities in the South China Sea. Geochemistry, Geophysics, Geosystems 19, 2049-2061.

https://doi.org/10.1029/2018GC007496

Based on the previously developed deep‐sea hybrid Raman insertion probe for cold seeps, the in situ detection of a cold seep vent and geochemistry analysis of fluids in chemosynthetic communities were conducted at the Formosa Ridge in the northern South China Sea. Three different methods were used to measure the components of the fluids erupting from the cold seep vent. The in situ Raman spectra of the cold seep fluids indicated the presence of gaseous CH4, C3H8, and H2S. The results indicate that the gases at this site are of biogenic origin; however, the presence of C3H8 suggests that thermogenic methane should not be excluded. The conclusion is also supported by the results of gas chromatography and stable carbon isotope analysis. More significantly, we found that the concentration of SO4

2− decreases with increasing depth, while the concentrations of CH4 and S8 increase in fluids in chemosynthetic communities, but without H2S. This finding indicates that the methane is oxidized by sulfate and that elemental sulfur is formed. This process usually occurs in marine sediments as the anaerobic oxidation of methane. Overall, the findings in this work provide a new insight into the geochemical analysis of cold seep fluids and in situ evidence of the oxidation of methane in the chemosynthetic communities near cold seeps.



In order to understand the influence of diagenetic water medium on hydrogen isotope of thermogenic coalbed gas, the hydrous and anhydrous pyrolytic simulation experiments have been carried out on herbaceous peat. We studied hydrogen isotope composition and its difference and evolution pattern of the pyrolysis hydrocarbon gases It was observed that diagenetic water medium exerts a significant influence on hydrogen isotopic composition of the pyrolysis hydrocarbon gases. The experiment added water with heavier hydrogen isotopic composition than peat-formed environmental water generated hydrocarbon gases with heavier hydrogen isotopic compositions. When peat was subject to continuous pyrolysis until 5.5%Ro, average δD values of the generated methane, ethane and propane were increased by 74‰, 42‰ and 66‰, respectively. It was considered that the reason for hydrous simulation experiment to increase hydrogen isotopic value of pyrolytic hydrocarbon gases is due to isotopic exchange between water-derived hydrogen and organic hydrogen. Mathematical models between the δD values of the hydrocarbon gases generated under the participation of freshwater with higher δD values and Ro values as well as between δD values of the generated hydrocarbon gases were established. These research results provide a scientific basis for the genetic study of thermogenic coalbed methane pyrolyzated by coal-forming materials formed in herbaceous marsh under the participation of diagenetic water media.

Dubois, D., Carrasco, N., Petrucciani, M., Vettier, L., Tigrine, S., Pernot, P., 2019. In situ investigation of neutrals involved in the formation of Titan tholins. Icarus 317, 182-196.


The Cassini Mission has greatly improved our understanding of the dynamics and chemical processes occurring in Titan's atmosphere. It has also provided us with more insight into the formation of the aerosols in the upper atmospheric layers.

However, the chemical composition and mechanisms leading to their formation were out of reach for the instruments onboard Cassini. In this context, it is deemed necessary to apply and exploit laboratory simulations to better understand the chemical reactivity occurring in the gas phase of Titan-like conditions. In the present work, we report gas phase results obtained from a plasma discharge simulating the chemical processes in Titan's ionosphere. We use the PAMPRE cold dusty plasma experiment with an N2CH4 gaseous mixture under controlled pressure and gas influx. An internal cryogenic trap has been developed to accumulate the gas products during their production and facilitate their detection. The cryogenic trap condenses the gas-phase precursors while they are forming, so that aerosols are no longer observed during the 2 h plasma discharge. We focus mainly on neutral products NH3, HCN, C2H2 and C2H4. The latter are identified and quantified by in situ mass spectrometry and infrared spectroscopy. We present here results from this experiment with mixing ratios of 90–10% and 99–1% N2CH4, covering the range of methane concentrations encountered in Titan's ionosphere. We also detect in situ heavy molecules (C7). In particular, we show the role of ethylene and other volatiles as key solid-phase precursors.

Duncombe, T.A., Raad, M.D., Bowen, B.P., Singh, A.K., Northen, T.R., 2018. Insulator nanostructure desorption ionization mass spectrometry. Analytical Chemistry 90, 9657-9661.

https://doi.org/10.1021/acs.analchem.8b01989

Surface-assisted laser desorption ionization (SALDI) is an approach for gas-phase ion generation for mass spectrometry using laser excitation on typically conductive or semiconductive nanostructures. Here, we introduce insulator nanostructure desorption ionization mass spectrometry (INDI-MS), a nanostructured polymer substrate for SALDI-MS analysis of small molecules and peptides. INDI-MS surfaces are produced through the self-assembly of a perfluoroalkyl silsesquioxane nanostructures in a single chemical vapor deposition silanization-step. We find that surfaces formed from the perfluorooctyltrichlorosilane monomer assemble semielliptical features with a 10 nm height, diameters between 10 and 50 nm, and have attomole–femtomole sensitivities for selected analytes. Surfaces prepared with silanes that either lack the trichloro or perfluoro groups, lack sensitivity. Further, we demonstrate that hydrophobic INDI regions can be micropatterned onto hydrophilic surfaces to perform on-chip self-desalting in an array format.

El-Sabagh, S.M., El-Naggar, A.Y., El Nady, M.M., Badr, I.A., Ebiad, M.A., Abdullah, E.S., 2018. Fingerprinting of biomarker characteristics of some Egyptian crude oils in Northern Western Desert as evidence for organic matter input and maturity level assessment. Egyptian Journal of Petroleum 27, 201-208.


This study describes the fingerprinting of crude oils from different Egyptian oil formations using gas chromatography (GC) and gas chromatography mass spectrometry (GC–MS). The samples were obtained from Gindi, Abu El gharadig, south deep Abu El gharadig, Dahab- Merier and Faghur basins

from Western Desert. Diagnostic biomarkers parameters applied in this study provide evidences about the source of organic matter, the depositional environment and maturity of the studied oils. The results showed that the crude oils of Faghur basin are believed to be originated from mixed source predominately terrestrial with chief contribution of clastic rocks deposited under oxic conditions. However, the crude oils from Gindi, Abu El gharadig, South deep Abu El gharadig and Dahab- Merier basins were generated from marine carbonate source rock deposited under anoxic depositional environment.

El Nady, M.M., Ramadan, F.S., Hammad, M.M., Mousa, D.A., Lotfy, N.M., 2018. Oil: Source rock correlations of Al Baraka oil field, Komombo basin, South Egypt: An implication from biomarkers characteristics. Petroleum Science and Technology 36, 1250-1257.

https://doi.org/10.1080/10916466.2018.1465978

The objectives of this study are the correlation between the oil samples recovered from the Lower Cretaceous reservoirs and Lower and Upper Cretaceous source rocks. The investigated biomarkers of five oils indicated the oils were derived from mixed marine and terrigenous (lacustrine) organic matter and deposited under suboxic to anoxic conditions. These oils were also generated from source rocks of high thermal maturity at the peak oil window. So, based on the molecular indicators of organic source input,depositional environment and maturity parameters of oils and extracts, we can conclude that the oil recovered from Al Baraka oil field were derived from Lower Cretaceous source rocks especially KomOmbo (B) source rocks where it reached the oil window. Furthermore, we can indicate that the other lower Cretaceous formations as Abu Ballas Formation will have the opportunity to generate and expel oil at the deeper part of the basin as shown in the eastern part of the basin.


https://doi.org/10.1080/10916466.2018.1468779

Effect of provenance of organic matter evaluated through the distribution of occurrence of triterpanes and steranes in surface sediments from coastal stations located in the Gulf of Suez Gulf. The samples have been studied in four coastal stations located in the Gulf of Suez namely: Al?Nasr Oil Company (NPC), West outlet of SOPC, Inlete of SOPC, and El-Sukhna of Loloha Beach. Saturated hydrocarbons were analyzed by gas chromatography?mass spectrometry, to assessing of organic content and maturity level of the sediments. The results showed that the hydrocarbons are originated mainly from predominance of petrogenic and biogenic hydrocarbons with high maturity level.

Englander, J.G., Brandt, A.R., Conley, S., Lyon, D.R., Jackson, R.B., 2018. Aerial interyear comparison and quantification of methane emissions persistence in the Bakken Formation of North Dakota, USA. Environmental Science & Technology 52, 8947-8953.


We performed an infrared optical gas imaging (OGI) survey by helicopter of hydrocarbon emissions in the Bakken formation of North Dakota. One year after an earlier survey of 682 well pads in September of 2014, the same helicopter crew resurveyed 353 well pads in 2015 to examine the persistence of emissions. Twenty-one newly producing well pads were added in the same sampling

blocks. An instrumented aircraft was also used to quantify emissions from 33 plumes identified by aerial OGI. Well pads emitting methane and ethane in 2014 were far more likely to be emitting in 2015 than would be expected by chance; Monte Carlo simulations suggest >5σ deviation (p < 0.0001) from random assignment of detectable emissions between survey years. Scaled up using basin-wide leakage estimates, the emissions quantified by aircraft are sufficient to explain previously observed basin-wide emissions of methane and ethane.


https://doi.org/10.1002/rcm.8201

Rationale:

Depsipeptides, or peptides with a mixture of amide and ester linkages, may have evolved into peptides on primordial Earth. Previous studies on depsipeptides utilized electrospray ionization ion mobility quadrupole time‐of‐flight (ESI‐IM‐QTOF) tandem mass spectrometry; such analysis was thorough yet time‐consuming. Here, a complementary matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) approach was optimized for rapid characterization of depsipeptide length and monomer composition.

Methods: Depsipeptide mixtures of varying hydrophobicity were formed by subjecting aqueous mixtures of α‐hydroxy acids and α‐amino acids to evaporative cycles. Ester and amide content of depsipeptides was orthogonally confirmed using infrared spectroscopy. MALDI‐TOF MS analysis was performed on a Voyager DE‐STR in reflection geometry and positive ion mode. Optimization parameters included choice of matrix, sample solvent, matrix‐to‐analyte ratio, and ionization additives.

Results: It was determined that evaporated depsipeptide samples should be mixed with 2,5‐dihydroxybenzoic acid (DHB) matrix in order to detect the highest number of unique signals. Low matrix‐to‐analyte ratios were found to generate higher quality spectra, likely due to a combination of matrix suppression and improved co‐crystallization. Using this optimized protocol, a new depsipeptide mixture was characterized.

Conclusions: Understanding the diversity and chemical evolution of proto‐peptides is of interest to origins‐of‐life research. Here, we have demonstrated MALDI‐TOF MS can be used to rapidly screen the length and monomer composition of model prebiotic peptides containing a mixture of ester and amide backbone linkages.

Fan, L.-F., Lin, S., Hsu, C.-W., Tseng, Y.-T., Yang, T.F., Huang, K.-M., 2018. Formation and preservation of authigenic pyrite in the methane dominated environment. Deep Sea Research Part I: Oceanographic Research Papers 138, 60-71.


Sulfate reduction could go through dissimilatory sulfate reduction and anaerobic methane oxidation couple with sulfate reduction (AOM-SR) with pyrite the end product. While AOM-SR is an important process in oxidizing methane and limiting methane entering the ocean, there is limited information available regarding pyrite formation and preservation under methane dominated environment. The purpose of this study is to report pyrite formation and preservation at a methane dominated

environment, the YuanAn Ridge, where methane seeps have been observed, and to evaluate how would that differ from typical anoxic environment. Pore water methane, sulfate, dissolved sulfide, barium, and sediment pyrite, barium/Al ratio and organic carbon in sediments were analyzed from sediments collected by piston cores on board the R/V Ocean Researcher I (OR-I) from the study environment.

The results showed methane flux is controlling pyrite formation in this methane dominated environment. Pyrite concentration is linearly correlated with methane flux with exceptions to shallower sulfate methane transition zone (SMTZ) sites where methane could have vent directly to the overlying water and contribute less to the pyrite formation. The more methane entering the SMTZ, the more pyrite formed and preserved in the sulfate methane transition zone sediments. Authigenic pyrite from dissimilatory sulfate reduction is a small fraction of the pyrite found in the methane dominant and low in organic carbon environment, with majority of pyrite derived from AOM-SR.

Large spatial variations on rate of sulfate reduction, pyrite and methane concentrations were observed in the studied area sediments. Depth of sulfate methane transition zone varied between 1 and 14 m and is a log function of methane flux. Pore water sulfate profiles displayed three different types, linear, concave up and down, indicating methane flux have varied in time.

Pyrite burial efficiency is high, approximately 50% of sulfate entering the SMTZ were preserved in sediments as pyrite. This efficiency of sulfate reduction through AOM-SR is much higher than pyrite formation from dissimilatory sulfate reduction in normal marine sediments. The AOM-SR and pyrite formation occurred at depth within the SMTZ favor a higher degree of pyrite preservation. Time require for the pyrite formation is about 4400 years in the YAR sediments, based on diffusion model calculation of barium sulfate precipitation.

Fan, R., Yang, X., Drury, C.F., Zhang, Z., 2018. Curve-fitting techniques improve the mid-infrared analysis of soil organic carbon: a case study for Brookston clay loam particle-size fractions. Scientific Reports 8, Artcile 12174.

https://doi.org/10.1038/s41598-018-30704-2

Few studies have evaluated structural features of soil organic carbon (SOC) in different soil particle fractions, especially SOC changes induced by tillage, using Fourier transformed mid-infrared (MIR) spectroscopy. To make a contribution in this context, soil samples of a Brookston clay loam (mesic Typic Argiaquoll) with averaged pH and organic matter concentration at 7.28 and 43.9 g kg−1, respectively, were collected from short-term no-tillage (NT97) and mouldboard plow (CT97) treatments initiated in 1997 and long-term no-tillage (NT83) and mouldboard plow (CT83) treatments initiated in 1983 under a corn-soybean rotation, and were separated into sand, silt, and clay fractions using sonication. Structural features of SOC in these soil fractions were investigated using curve-fitting analysis of mid-infrared (MIR) spectra. Aromatic C content was found to be greater in clay- than in sand-sized fractions, while aliphatic C content was higher in sand- than in silt- and clay-sized particles. With decrease in tillage intensity, the aliphatic C gradually increased in sand- and clay-sized fractions but not in the silt-sized fraction. The aliphatic C content in sand fraction was significantly greater in NT83 than CT83 (P < 0.05). The aromatic C in silt- and clay-sized fractions was greater in NT83 than in both CT soils, whereas aromatic C contents were higher in both CT soils than in NT83 soil. Significantly higher aromatic/aliphatic C ratio in CT83 than NT83 was found in sand-sized fractions, while the opposite trend was found in the silt-sized fraction. These findings were not apparent until the curve-fitting technique was employed, which has the capacity to quantify many

overlapped bands in the spectra. This study demonstrates that the curve-fitting of MIR spectra advances the analysis of organic matter in soil samples.

Fang, Z., Chelme-Ayala, P., Shi, Q., Xu, C., Gamal El-Din, M., 2018. Degradation of naphthenic acid model compounds in aqueous solution by UV activated persulfate: Influencing factors, kinetics and reaction mechanisms. Chemosphere 211, 271-277.


Naphthenic acids (NAs) are one of the constituents of concerns in oil sands process water (OSPW) because of their persistence and recalcitrance. Herein, we investigated the degradation of five model NA compounds by UV-activated persulfate (UV/persulfate) process under medium-pressure UV lamp irradiation at pH 8.0. UV/persulfate process showed higher degradation efficiency towards cyclohexanoic acid (CHA) compared to UV/H2O2 process under the same experimental conditions. CHA (0.39 mM) was completely removed within 30 min when 2 mM persulfate was used as oxidant, while more than 60 min were needed for the UV/H2O2 process. The removal of CHA decreased from 100% to 10% when 300 mM tert-butyl alcohol (TBA) was used as the scavenger, indicating that hydroxyl radical (OH) was responsible for the CHA degradation in the UV/persulfate process. Sulfate (SO4

−) radicals reacted slowly with CHA in the UV/persulfate process with a second-order rate constant of k = 5.3 × 107 M−1s−1. Relative kinetics studies using binary mixtures of model NA compounds showed similar structure-reactivity to that under UV/H2O2 process. NAs with long carbon chain, cyclic ring, and aromatic ring were more reactive in the UV/persulfate process. The presence of high concentration of chloride ions dramatically inhibited the reaction. The OH radicals in the UV/persulfate process were generated by capturing OH− in solutions, as evidenced by the decrease of the pH value from 8.0 to 2.8 before and after treatment, respectively, in a pure water matrix. Primary intermediate products (oxy-CHA, hydroxyl-CHA, and dihydroxyl-CHA) of UV/persulfate process were confirmed by UPLC-MS.

Feeser, K.L., Van Horn, D.J., Buelow, H.N., Colman, D.R., McHugh, T.A., Okie, J.G., Schwartz, E., Takacs-Vesbach, C.D., 2018. Local and regional scale heterogeneity drive bacterial community diversity and composition in a polar desert. Frontiers in Microbiology 9, 1928. doi: 10.3389/fmicb.2018.01928.


The distribution of organisms in an environment is neither uniform nor random but is instead spatially patterned. The factors that control this patterning are complex and the underlying mechanisms are poorly understood. Soil microbes are critical to ecosystem function but exhibit highly complex distributions and community dynamics due in large part to the scale-dependent effects of environmental heterogeneity. To better understand the impact of environmental heterogeneity on the distribution of soil microbes, we sequenced the 16S rRNA gene from bacterial communities in the microbe-dominated polar desert ecosystem of the McMurdo Dry Valleys (MDV), Antarctica. Significant differences in key edaphic variables and alpha diversity were observed among the three lake basins of the Taylor Valley (Kruskal–Wallis; pH: χ2 = 68.89, P < 0.001, conductivity: χ2 = 35.03, P < 0.001, observed species: χ2 = 7.98, P = 0.019 and inverse Simpson: χ2 = 18.52, P < 0.001) and each basin supported distinctive microbial communities (ANOSIM R = 0.466, P = 0.001, random forest ratio of 14.1). However, relationships between community structure and edaphic characteristics were highly variable and contextual, ranging in magnitude and direction across regional, basin, and local scales. Correlations among edaphic factors (pH and soil conductivity) and the relative abundance of specific phyla were most pronounced along local environmental gradients in the Lake

Fryxell basin where Acidobacteria, Bacteroidetes, and Proteobacteria declined while Deinococcus–Thermus and Gemmatimonadetes increased with soil conductivity (all P < 0.1). Species richness was most strongly related to the soil conductivity gradient present within this study system. We suggest that the relative importance of pH versus soil conductivity in structuring microbial communities is related to the length of edaphic gradients and the spatial scale of sampling. These results highlight the importance of conducting studies over large ranges of key environmental gradients and across multiple spatial scales to assess the influence of environmental heterogeneity on the composition and diversity of microbial communities.

Fernández, P.J., Mongle, C.S., Leakey, L., Proctor, D.J., Orr, C.M., Patel, B.A., Almécija, S., Tocheri, M.W., Jungers, W.L., 2018. Evolution and function of the hominin forefoot. Proceedings of the National Academy of Sciences 115, 8746-8751.


Significance: A critical step in the evolutionary history leading to the origins of humankind was the adoption of habitual bipedal locomotion by our hominin ancestors. We have identified novel bony shape variables in the forefoot across extant anthropoids and extinct hominins that are linked functionally to the emergence of bipedal walking. Results indicate a consistent and generalizable pattern in hominin pedal evolution that spans from Ardipithecus to early Homo—the relatively late derivation of a modern hallux in comparison with the lateral rays. These data provide novel morphological and macroevolutionary evidence for how and when the hominin pedal skeleton evolved to accommodate the unique biomechanical demands of bipedalism.

Abstract: The primate foot functions as a grasping organ. As such, its bones, soft tissues, and joints evolved to maximize power and stability in a variety of grasping configurations. Humans are the obvious exception to this primate pattern, with feet that evolved to support the unique biomechanical demands of bipedal locomotion. Of key functional importance to bipedalism is the morphology of the joints at the forefoot, known as the metatarsophalangeal joints (MTPJs), but a comprehensive analysis of hominin MTPJ morphology is currently lacking. Here we present the results of a multivariate shape and Bayesian phylogenetic comparative analyses of metatarsals (MTs) from a broad selection of anthropoid primates (including fossil apes and stem catarrhines) and most of the early hominin pedal fossil record, including the oldest hominin for which good pedal remains exist, Ardipithecus ramidus. Results corroborate the importance of specific bony morphologies such as dorsal MT head expansion and “doming” to the evolution of terrestrial bipedalism in hominins. Further, our evolutionary models reveal that the MT1 of Ar. ramidus shifts away from the reconstructed optimum of our last common ancestor with apes, but not necessarily in the direction of modern humans. However, the lateral rays of Ar. ramidus are transformed in a more human-like direction, suggesting that they were the digits first recruited by hominins into the primary role of terrestrial propulsion. This pattern of evolutionary change is seen consistently throughout the evolution of the foot, highlighting the mosaic nature of pedal evolution and the emergence of a derived, modern hallux relatively late in human evolution.

Fillol-Salom, A., Martínez-Rubio, R., Abdulrahman, R.F., Chen, J., Davies, R., Penadés, J.R., 2018. Phage-inducible chromosomal islands are ubiquitous within the bacterial universe. The ISME Journal 12, 2114-2128.

https://doi.org/10.1038/s41396-018-0156-3

Phage-inducible chromosomal islands (PICIs) are a recently discovered family of pathogenicity islands that contribute substantively to horizontal gene transfer, host adaptation and virulence in Gram-positive cocci. Here we report that similar elements also occur widely in Gram-negative bacteria. As with the PICIs from Gram-positive cocci, their uniqueness is defined by a constellation of features: unique and specific attachment sites, exclusive PICI genes, a phage-dependent mechanism of induction, conserved replication origin organization, convergent mechanisms of phage interference, and specific packaging of PICI DNA into phage-like infectious particles, resulting in very high transfer frequencies. We suggest that the PICIs represent two or more distinct lineages, have spread widely throughout the bacterial world, and have diverged much more slowly than their host organisms or their prophage cousins. Overall, these findings represent the discovery of a universal class of mobile genetic elements.

Fink, R., Amann-Hildenbrand, A., Bertier, P., Littke, R., 2018. Pore structure, gas storage and matrix transport characteristics of lacustrine Newark shale. Marine and Petroleum Geology 97, 525-539.


Shale gas production in the U.S. fuelled research activities in unconventional reservoir rock characterization. Most studies focused on organic-rich shales of marine origin, while disregarding lacustrine sequences. In this study, thirteen lacustrine shale samples from the Newark Basin, NJ, USA are comprehensively characterised in terms of pore structure, gas storage and matrix transport characteristics. These thermally overmature (VRr 1.4–2.7%) shales have a Na-rich, heterogeneous mineralogy with TOC contents of up to 3.6%.

Methane sorption capacity and pore structure parameters as identified with low-pressure N2 physisorption (microporosity, BET surface area) are neither interrelated with each other nor with any shale components (e.g. clay content, TOC).

In contrast, porosity shows a positive correlation with TOC content, which is also typical for many thermally overmature marine shale sequences. Correspondingly, porosity and TOC positively correlate to bedding parallel matrix permeability coefficients (between 2 and 80 nD at 40 MPa effective stress). In contrast, permeability coefficients perpendicular to bedding are two to three orders of magnitude lower.

Compared to previous studies on marine lithotypes, Newark shales have rather poor gas storage properties with average He-porosities of 2.3% and average methane sorption capacities of 0.047 mmol g−1.

Fiorillo, A.R., McCarthy, P.J., Kobayashi, Y., Tomsich, C.S., Tykoski, R.S., Lee, Y.-N., Tanaka, T., Noto, C.R., 2018. An unusual association of hadrosaur and therizinosaur tracks within Late Cretaceous rocks of Denali National Park, Alaska. Scientific Reports 8, Article 11706.

https://doi.org/10.1038/s41598-018-30110-8

We report details of a unique association of hadrosaur and therizinosaur tracks found in the Late Cretaceous lower Cantwell Formation, Denali National Park, central Alaska Range, Alaska. This rock unit is now well-documented as a source of thousands of fossil footprints of vertebrates such as fishes, pterosaurs, and avialan and non-avialan dinosaurs. The lower Cantwell Formation in this area consists of numerous fining-upward successions of conglomerates and pebbly sandstones, cross-stratified and massive sandstones, interbedded sandstones and siltstones, organic-rich siltstones and shales, and rare, thin, bentonites, typically bounded by thin coal seams, and it contains a diverse fossil

flora. We report the first North American co-occurrence of tracks attributable to hadrosaurs and therizinosaurs in the lower Cantwell Formation. Although previously un-reported in North America, this association of hadrosaur and therizinosaur tracks is more characteristic of the correlative Nemegt Formation in central Asia, perhaps suggesting that parameters defining the continental ecosystem of central Asia were also present in this part of Alaska during the Latest Cretaceous.

Fornaro, T., Brucato, J.R., Feuillie, C., Sverjensky, D.A., Hazen, R.M., Brunetto, R., D'Amore, M., Barone, V., 2018. Binding of nucleic acid components to the serpentinite-hosted hydrothermal mineral brucite. Astrobiology 18, 989-1007.

https://www.liebertpub.com/doi/abs/10.1089/ast.2017.1784

The adsorption of nucleic acid components onto the serpentinite-hosted hydrothermal mineral brucite has been investigated experimentally by determining the equilibrium adsorption isotherms in aqueous solution. Thermodynamic characterization of the adsorption data has been performed using the extended triple-layer model (ETLM) to establish a model for the stoichiometry and equilibrium constants of surface complexes. Infrared characterization of the molecule–mineral complexes has helped gain insight into the molecular functional groups directly interacting with the mineral surface. Quantum mechanical calculations have been carried out to identify the possible complexes formed on surfaces by nucleic acid components and their binding configurations on mineral surfaces, both in the presence of water molecules and in water-free conditions. The results indicate that brucite favors adsorption of nucleotides with respect to nucleosides and nucleobases from dilute aqueous environments. The surface of this mineral is able to induce well-defined orientations of the molecules through specific molecule–mineral interactions. This result suggests plausible roles of the mineral brucite in assisting prebiotic molecular self-organization. Furthermore, the detection of the infrared spectroscopic features of such building blocks of life adsorbed on brucite at very low degrees of coverage provides important support to life detection investigations.

Fouad, W.A., Abutaqiya, M.I.L., Mogensen, K., Yap, Y.F., Goharzadeh, A., Vargas, F.M., Vega, L.F., 2018. Predictive model for pressure–volume–temperature properties and asphaltene instability of crude oils under gas injection. Energy & Fuels 32, 8318-8328.


A new approach based on the statistical associating fluid theory is presented here to model eight light crude oils, with the saturate, aromatic, resin, and asphaltene analysis as the only input for the model. Within the characterization procedure of Punnapala and Vargas ( Fuel 2013, 108, 417−429, 10.1016/j.fuel.2012.12.058), the aromaticity parameter and the asphaltene molecular weight were fixed to all crude oil samples, while the asphaltene aromaticity is the only fitted parameter of the model. A correlation for this parameter with the flashed gas molecular weight allows for full predictions of the phase behavior without the need of any asphaltene onset data. The predictive molecular model was used to study asphaltene instability as a function of injected CO2 and natural gas concentration. The model can also accurately reproduce routine pressure–volume–temperature experiments, such as constant composition expansion, differential vaporization, and multi-stage separation tests, performed on the crude oils, thereby providing a unified framework for phase behavior studies.

Fournier, G.P., Poole, A.M., 2018. A briefly argued case that Asgard archaea are part of the eukaryote tree. Frontiers in Microbiology 9, 1896. doi: 10.3389/fmicb.2018.01896.


The recent discovery of the Lokiarchaeota and other members of the Asgard superphylum suggests that closer analysis of the cell biology and evolution of these groups may help shed light on the origin of the eukaryote cell. Asgard lineages often appear in molecular phylogenies as closely related to eukaryotes, and possess ‘Eukaryote Signature Proteins’ coded by genes previously thought to be unique to eukaryotes. This phylogenetic affinity to eukaryotes has been widely interpreted as indicating that Asgard lineages are “eukaryote-like archaea”, with eukaryotes evolving from within a paraphyletic Archaea. Guided by the established principles of systematics, we examine the potential implications of the monophyly of Asgard lineages and Eukarya. We show that a helpful parallel case is that of Synapsida, a group that includes modern mammals and their more ‘reptile-like’ ancestors, united by shared derived characters that evolved in their common ancestor. While this group contains extinct members that share many similarities with modern reptiles and their extinct relatives, they are evolutionarily distinct from Sauropsida, the group which includes modern birds, reptiles, and all other amniotes. Similarly, Asgard lineages and eukaryotes are united by shared derived characters to the exclusion of all other groups. Consequently, the Asgard group is not only highly informative for our understanding of eukaryogenesis, but may be better understood as being early diverging members of a broader group including eukaryotes, for which we propose the name “Eukaryomorpha”. Significantly, this means that the relationship between Eukarya and Asgard lineages cannot, on its own, resolve the debate over 2 vs 3 Domains of life; instead, resolving this debate depends upon identifying the root of Archaea with respect to Bacteria.



Important high molecular weight hydrocarbons present in petroleum are commonly referred to as petroleum waxes. The paraffin deposition caused by this class of compounds in pipelines results in a gradual decrease of flow rate and therefore in equipment damage, which increases the costs of oil production. These compounds typically extend to about C70 in most types of petroleum. One of the most effective analytical methods for characterization of high molecular weight paraffins in petroleum is high-temperature gas chromatography (HT-GC). The present investigation is focused on the optimization and application of a high-temperature comprehensive two-dimensional gas chromatographic (HT-GC × GC) method, with flame ionization detection (FID) and time-of-flight mass spectrometry (TOFMS) for the quantitative and qualitative analysis of Brazilian whole crude oils. A set of fourteen crude oils, including three from the pre-salt layer, were studied. The contents and distribution characteristics of high molecular weight paraffins in various crude oils were summarized. Linear paraffins in the range of C16–C60 were detected and identified while maintaining the efficiency of the chromatographic separation. iso-Paraffin and naphthene compounds in the range of C17–C60 were also identified and quantified in these crude oils.

Fransner, F., Fransson, A., Humborg, C., Gustafsson, E., Tedesco, L., Hordoir, R., Nycander, J., 2018. Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters. Biogeosciences Discussions 2018, 1-27.

https://doi.org/10.5194/bg-2018-333

Coastal seas receive large amounts of terrestrially derived organic carbon (OC). The fate of this carbon, and its impact on the marine environment, is however poorly understood. Here we combine underway CO2 partial pressure (pCO2) measurements with coupled 3D hydrodynamical-biogeochemical modelling to investigate whether remineralization of terrestrial dissolved organic carbon (tDOC) can explain CO2 supersaturated surface waters in the Gulf of Bothnia, a subarctic estuary. We find that a substantial remineralization of tDOC, and that a strong tDOC induced light attenuation dampening the primary production, is required to reproduce the observed CO2 supersaturated waters in the nearshore areas. A removal rate of tDOC of the order of one year, estimated in a previous modelling study in the same area, gives a good agreement between modelled and observed pCO2. The remineralization rate is on the same order as bacterial degradation rates calculated from published incubation experiments, suggesting that this remineralization could be caused by bacterial degradation. Furthermore, the observed high pCO2 values during the ice covered season argues against photochemical degradation as the main removal mechanism. All of the remineralized tDOC is outgassed to the atmosphere in the model, turning the northernmost part of the Gulf of Bothnia to a source of atmospheric CO2.

Frei, R., Paulukat, C., Bruggmann, S., Klaebe, R.M., 2018. A systematic look at chromium isotopes in modern shells – implications for paleo-environmental reconstructions. Biogeosciences 15, 4905-4922.

https://doi.org/10.5194/bg-15-4905-2018

The chromium isotope system (53Cr∕52Cr, expressed as δ53Cr relative to NIST SRM 979) in marine biogenic and non-biogenic carbonates is currently being evaluated as a proxy for the redox state of the ocean. Previous work has concentrated on using corals and foraminifera for this purpose, but investigations focusing on the behavior of Cr in bivalves as potential archives are lacking. Due to their often good preservation, fossil marine biogenic carbonates have the potential to serve as useful archives for the reconstruction of past ocean redox fluctuations and eventually link those to climatic changes throughout Earth's history. Here, we present an evaluation of the Cr isotope system in shells of some modern bivalves. Shell species from Lucidinadae, Cardiidae, Glycimerididae and Pectenidae, collected systematically from one Mediterranean location (Playa Poniente, Benidorm, Spain) over a 3-year period reveal δ53Cr values ranging from 0.15‰ to 0.65‰, values that are systematically below the local seawater δ53Cr value of 0.83±0.05‰. This attests to a significant reduction of dissolved seawater chromium in the process leading to calcification and thus for control of Cr isotope fractionation during biological routes. A similar, constant offset in δ53Cr values relative to surface seawater is observed in shells from Mytilius edulis from an arctic location (Godhavn, Disko Bay, Greenland). Chromium concentrations in the studied shells are significantly controlled by organic matter and typically range from 0.020 to 0.100ppm, with some higher concentrations of up to 0.163ppm recorded in Pectenidae. We also observe subtle, species-dependent differences in average Cr isotope signatures in the samples from Playa Poniente, particularly of Lucidinadae and Cardiidae, with considerably depressed and elevated δ53Cr values, respectively, relative to the other species investigated. Intra-species heterogeneities, both in Cr concentrations and δ53Cr values, are favorably seen to result from vital effects during shell calcification rather than from heterogeneous seawater composition. This is because we observe that the surface seawater composition in the particular Playa Poniente location remained constant during the month of July of the 3 years we collected bivalve samples. Intra-shell heterogeneities – associated with growth zones reflecting one to several years of growth, both in δ53Cr and Cr concentrations – are observed in a sample of Placuna placenta and Mimachlamys townsendi. We suspect that these variations are, at least partially, related to seasonal changes in δ53Cr of surface seawaters. Recognizing the importance of organic substances in the bivalve shells, we propose a model whereby reduction of Cr(VI) originally contained in the seawater as chromate ion and transported to the calcifying space, to Cr(III), is effectively adsorbed onto

organic macromolecules which eventually get included in the growing shell carbonates. This study, with its definition of statistically sound offsets in δ53Cr values of certain bivalve species from ambient seawater, forms a base for future investigations aimed at using fossil shells as archives for the reconstruction of paleo-seawater redox fluctuations.

Fu, C., Yu, J., Liu, N., 2018. Nanoparticle-stabilized CO2 foam for waterflooded residual oil recovery. Fuel 234, 809-813.


This paper presents a series of studies of nanoparticle-stabilized CO2-foam for waterflooded residual oil recovery. A stable CO2 foam was generated as CO2/nanosilica dispersion flowed through a porous media. The generated CO2 foam could reduce CO2 mobility and improve CO2 sweep efficiency in CO2 flooding. The particle-stabilized CO2 foam has also been observed to improve residual oil recovery after waterflooding. Effects of pressure and temperature on the performance of the CO2 foam in residual oil recovery were investigated. The results indicated that the residual oil recovery (percentage of waterflooded residual oil) by CO2/nanosilica flooding increased from 64.9% to 75.8% when the pressure was increased from 1200 psi to 2500 psi. When temperature increased from 25 °C to 60 °C, the residual oil recovery by CO2/nanosilica flooding decreased from 62.6% to 52.1%.

Fujisaki, W., Matsui, Y., Asanuma, H., Sawaki, Y., Suzuki, K., Maruyama, S., 2018. Global perturbations of carbon cycle during the Triassic–Jurassic transition recorded in the mid-Panthalassa. Earth and Planetary Science Letters 500, 105-116.


To examine environmental changes in the biosphere during the Triassic–Jurassic transition, with a particular focus on the global carbon cycle related to Central Atlantic Magmatic Provinces (CAMP) volcanism in the mid-Panthalassa, we established stratigraphic δ13Corg variations using Rhaetian (Late Triassic) to Hettangian (Early Jurassic) shales interbedded within deep-sea cherts in the Katsuyama section in the Mino-Tanba belt, SW Japan. High-resolution record of Rhaetian to Hettangian δ13Corg values in the mid-Panthalassa contain three distinct negative carbon isotopic excursions (NCIEs) before and across the Triassic–Jurassic boundary (TJB): the Rhaetian NCIE1 and NCIE2 show a deviation of 5.0‰ from ca. −24.0‰ to ca. −29.0‰, whereas NCIE3 across the TJB shows a 3.5‰ deviation from ca. −23.5‰ to ca. −27.0‰. Our newly obtained NCIEs in the deep mid-Panthalassa can be correlated with the δ13Corg records in the shallow-marine Tethyan regions (i.e., precursor, initial, and main CIEs), suggesting that three NCIEs in the Tethys and mid-Panthalassa likely reflected the global perturbations of the carbon cycle. Three NCIEs before and across the TJB can be interpreted as the consequence of the multiple CAMP volcanic episodes; i.e., the release of thermogenic methane from organic-rich sediments by CAMP intrusive rocks for NCIE1 and large-scale volcanically derived carbon species for NCIE2 and NCIE3. In addition, progressive increase of atmospheric pCO2 throughout three NCIEs was possibly attributed to accumulation of volcanically derived CO2 from multiple CAMP eruptions, which resulted in the development of ocean acidification across the TJB. On the other hand, in view of the oxic conditions in the deep mid-Panthalassa during three NCIEs, the development of coeval oceanic anoxic–euxinic conditions was restricted solely to shallow-marine regions. Therefore, ocean acidification together with localized shallow-marine anoxia acted as environmental stresses on the biosphere, which eventually resulted in the severe biotic crisis at the end of the Triassic.



Soil contamination with petroleum, especially in the area of oil wells, is a serious environmental problem. Restoring soil subjected to long-term pollution to its original state is very difficult. Under such conditions, unique bacterial communities develop in the soil that are adapted to the contaminated conditions. Analysis of the structure and function of these microorganisms can be a source of valuable information with regard to bioremediation. The aim of this study was to evaluate structural and functional diversity of the bacterial communities in soils with long-term impacts from petroleum. Samples were taken from the three oldest oil wells at the Crude Oil Mine site in Węglówka, Poland; the oldest was established in 1888. They were collected at 2 distances: (1) within a radius of 0.5 m from the oil wells, representing soil strongly contaminated with petroleum; and (2) 3 m from the oil wells as the controls. The samples were analyzed by 16S rRNA sequencing and the community level physiological profiling (CLPP) method in order to better understand both the genetic and functional structure of soil collected from under oil wells. Significant differences were found in the soil samples with regard to bacterial communities. The soils taken within 0.5 m of the oil wells were characterized by the highest biodiversity indexes. Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria were strongly correlated with biological activity in these soils. Families of Alphaproteobacteria were also dominant, including: Bradyrhizobiaceae, Rhizobiaceae, Rhodobacteraceae, Acetobacteraceae, Hyphomicrobiaceae, and Sphingomonadaceae. The study showed that the long term contamination of soil changes bacterial communities and their metabolic activity. Even so, natural bioremediation leads to the formation of specific groups of bacteria that actively grow at the site of contamination in the soil.

Gallagher, S.J., Sagawa, T., Henderson, A.C.G., Saavedra-Pellitero, M., De Vleeschouwer, D., Black, H., Itaki, T., Toucanne, S., Bassetti, M.-A., Clemens, S., Anderson, W., Alvarez-Zarikian, C., Tada, R., 2018. East Asian monsoon history and paleoceanography of the Japan Sea over the last 460,000 years. Paleoceanography and Paleoclimatology 33, 683-702.

https://doi.org/10.1029/2018PA003331

Abstract The Japan Sea is directly influenced by the Asian monsoon, a system that transports moisture and heat across southeast Asia during the boreal summer, and is a major driver of the Earth's ocean-atmospheric circulation. Foraminiferal and facies analyses of a 460-kyr record from Integrated Ocean Drilling Program Expedition 346 Site U1427 in the Japan Sea reveal a record of nutrient flux and oxygenation that varied due to sea level and East Asian monsoon intensity. The East Asian summer monsoon (EASM) was most intense during marine isotope stage (MIS) 5e, MIS 7e, MIS 9e, and MIS 11c when the Tsushima Warm Current flowed into an unrestricted well-mixed normal salinity Japan Sea, whereas East Asian winter monsoon (EAWM) conditions dominated MIS 2, MIS 4, MIS 6, and MIS 8 when sea level minima restricted the Japan Sea resulting in low-salinity and oxygen conditions in the absence of Tsushima flow. Reduced oxygen stratified, low-salinity, and higher productivity oceanic conditions characterize Terminations TV, TIII, TII, and TI when East China Sea coastal waters breached the Tsushima Strait. Chinese loess, cave, and Lake Biwa (Japan) and U1427 proxy records suggest EASM intensification during low to high insolation transitions, whereas the strongest EAWM prevailed during lowest insolation periods or high to low insolation transitions. Ice sheet/CO2 forcing leads to the strongest EAWM events in glacials and enhanced EASM in interglacials. Mismatches between proxy patterns suggest that latitudinal and land/sea

thermal contrasts played a role in East Asian monsoon variability, suggesting that a complex interplay between ice sheet dynamics, insolation, and thermal gradients controls monsoonal intensity.

Gao, L., Zhou, Z., Reyes, A.V., Guo, L., 2018. Yields and characterization of dissolved organic matter from different aged soils in northern Alaska. Journal of Geophysical Research: Biogeosciences 123, 2035-2052.

https://doi.org/10.1029/2018JG004408

Abstract: Soil organic matter (SOM) in northern high‐latitude regions is a major component of the global carbon cycle. However, the yield of soil‐dissolved organic matter (DOM) during soil‐water interactions and its chemical characteristics and reactivities remain poorly understood. We report here elemental composition and isotopic signatures of bulk‐SOM from northern Alaska, and yields of water‐leachable soil‐DOM, including dissolved organic carbon, dissolved organic nitrogen, and dissolved organic phosphorus, and nutrients (dissolved inorganic nitrogen and phosphate). The bulk‐SOM contained 5,400–373,900 μg‐C/g‐soil, 500–12,610 μg‐N/g‐soil, and 38.6–384 μg‐P/g‐soil, with a C/N ratio of 13–37 and a C/P ratio of 80–3,911. The water‐extractable dissolved organic carbon, dissolved organic nitrogen, and dissolved organic phosphorus only accounted for 0.58–2.5%, 0.91–3.4%, and 1.2–3.0% of their corresponding total soil‐OC, N, and OP, respectively. While SOM‐δ13C was less variable (−27.08‰ to −26.49‰) showing the same overall C source, 14C‐ages varied widely from 1,170 ± 20 to 16,200 ± 55 years before present, indicating different deposition‐conditions and subsequent‐processes among the soil samples. The specific‐UV‐absorbance at 254 nm (or aromaticity) of soil‐DOM differed considerably and was negatively correlated to spectral slope values. A humic‐like (C1), a low‐molecular‐weight fulvic‐like (C2), and a protein‐like component (C3) were identified as the major fluorescent‐DOM components. The C3/C2 and C3/C1 ratios generally increased with SOM‐14C‐age, suggesting a preferential degradation/transformation of humic‐like and fulvic‐like components or a transformation/production of protein‐like components within permafrost. Both biological and humification indices increased with 14C‐age, excluding the oldest soil, which pointed to a preferential preservation or transformation/production of protein‐like DOM within permafrost, implying that soil‐DOM derived from old permafrost can be highly vulnerable and readily decomposed upon permafrost thaw.

Plain Language Summary: The yields of soil dissolved organic matter (DOM) and nutrients (N and P) from different aged soils in northern Alaska were quantified in the laboratory mimicking soil‐water interactions upon permafrost thaw. The overall fluxes of soil‐DOM and nutrients can significantly influence carbon and nutrient cycle and the ecosystem as a whole in Arctic waterways and coastal environment although the yields were generally within 4% of their corresponding total mass in the bulk soil. Humic‐like substances with high optical reactivity were the major organic components preserved in permafrost, but the relative percentage of protein‐like components having high biological activity increased with increasing soil C‐14 age. This implies that soil‐DOM released from old‐permafrost thaw can be highly vulnerable and readily decomposed, causing a positive feedback to climate change.

Garcia-Fresca, B., Pinkston, D., Loucks, R.G., LeFever, R., 2018. The Three Forks playa lake depositional model: Implications for characterization and development of an unconventional carbonate play. American Association of Petroleum Geologists Bulletin 102, 1455-1488.

http://dx.doi.org/10.1306/12081716510

The Upper Devonian Three Forks Formation of the Williston Basin is an important reservoir interval in the Bakken petroleum system, with estimates suggesting greater than 3.7 billion bbl of recoverable oil. Detailed stratigraphic analyses are sparse, but current studies propose shallow marine, tidal flat, or coastal sabkha environments for its deposition. Based on stratigraphic, sedimentological, and petrographic analyses of 28 cores, we infer that the Three Forks Formation was deposited in a continental setting with little to no marine influence. The setting was subaerial to subaqueous environments comparable to those found in playa lake systems or continental sabkhas. Late Devonian paleography and tectonics provided the isolation and slow subsidence of the Williston Basin that led to the accumulation of the Three Forks Formation in a hot and arid climate. Occasional floods were responsible for the deposition of the terrigenous sediments, debrite-like deposits, reworking, bedforms, scouring, and erosional surfaces. Flood waters collected in ephemeral lakes and ponds evaporated, resulting in the deposition of subaqueous dolomite, anhydrite, and even halite. The ponds and lakes progressively evaporated and contracted until they eventually dried out. The drying is characterized by dewatering structures, subaerially exposed and transported sediments with ripples, scour surfaces, evaporite cemented surfaces, evaporite removal breccias, halite pseudomorphs, and a variety of cracks. Vertical successions record an upward trend of increasing proportions of subaqueous facies, indicating a transition from arid to relatively less arid climatic conditions during Three Forks deposition. This depositional system resulted in the accumulation of a complex mosaic of lithologies composed of different proportions and textures of silt-sized detrital dolomite and quartz, clay, and evaporites in patchy to bull’s-eye configurations. This depositional model provides a coherent understanding of the existing depositional lithofacies and their petrophysical and geomechanical properties and provides the background for the prediction of their lateral distribution from wire-line logs.


https://doi.org/10.1029/2018JG004384

The ocean continental shelves host the largest global reservoir of methane (CH4). Despite the great extent of these CH4 reservoirs, much of the CH4 released into deep ocean environments appear to dissolve in seawater prior to atmospheric emission. Once dissolved in ocean water, the CH4 emitted can be aerobically oxidized and converted into either carbon dioxide (CO2) or biomass. While hypotheses have been levied suggesting that the CO2 produced from aerobic methane oxidation could enhance ocean acidification, no empirical research has been performed to confirm or refute this hypothesis. The work presented here investigates local changes in seawater‐dissolved CO2 and pH in a region that is experiencing active CH4 seepage near the upper stability boundary of methane clathrate hydrates. We show that in an area of elevated CH4 concentrations and aerobic oxidation rates, Hudson Canyon, aerobic CH4 oxidation is only responsible for 0.3 ± 0.2% of the observed change in dissolved inorganic carbon. Measurements further show that the remineralization of both old marine and young terrestrial organic carbon is contributing more substantially to the observed changes. While this investigation did not investigate chronic, multiyear changes in ocean acidification due to CH4 oxidation, these results suggest that over short timescales, CH4 oxidation in seep fields does not have an acute influence on seawater pH.


https://doi.org/10.1306/1107171616617170

The Neoproterozoic strata of the Sichuan Basin are a key target for oil and gas. To evaluate the hydrocarbon evolution and its relationship with tectonic events in the Micang Shan uplift, northernmost Sichuan Basin, we apply solid bitumen geochemistry (bitumen reflectance and fluorescence) and Re-Os geochronology.

The geochemistry of the solid bitumen indicates that it is highly mature pyrobitumen that formed contemporaneously with dry-gas generation during oil thermal cracking. The pyrobitumen is enriched in both Re (∼106–191 ppb) and Os (∼3030–5670 parts per trillion). The Re-Os isotope data imply an Early Jurassic date for pyrobitumen formation, which coincides well with age estimates from fluid-inclusion data and basin modeling. The Re-Os date for pyrobitumen formation coupled with previously presented apatite fission-track (AFT) analysis show that exhumation of the Neoproterozoic strata occurred during the Cretaceous in the Micang Shan uplift. This extensive uplift led to the erosion of any potential gas reservoirs and surface exposure of bitumen-bearing Neoproterozoic strata. In contrast, the more southern and central portions of the Sichuan Basin have experienced less severe exhumation and, as a result, Neoproterozoic-sourced gas systems are present. This study shows that, through the combined application of Re-Os and AFT methodologies, the timing of gas generation and subsequent erosion of any potential gas reservoirs in the Micang Shan uplift, northern Sichuan Basin, can be quantified. Moreover, the Re-Os and AFT data illustrate the potential to constrain the timing of gas generation in petroleum systems worldwide.

Geng, J., Ding, H., Han, P., Wu, Y., Bai, B., 2018. Transportation and potential enhanced oil recovery mechanisms of nanogels in sandstone. Energy & Fuels 32, 8358-8365.


The transportation and potential enhanced oil recovery mechanisms of nanosized cross-linked polymeric particles (nanogels) with different charges are described herein. Three nanogels with different types of charges have been synthesized by suspension polymerization using acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and [2-(acryloyloxy)ethyl] trimethylammonium chloride (AETAC) monomers. The charged nanogels showed spherical morphology, porous structures, and narrow size distribution. The charged nanogels were able to adsorb onto the rock surface and modify the wettability, a critical parameter of the nanogel to recover residual oil. In addition, the static and dynamic adsorption of charged nanogels in sandstone has been demonstrated. Furthermore, the charged nanogels could reduce the permeability of water much more than the permeability of oil and emulsify residual oil as demonstrated by core flooding experiments. The nanogels with appropriate charges could offer the candidate through disproportionate permeability reduction and in situ emulsification for enhanced oil recovery.

Ghosh, S., Rodrigues, S., Varma, A.K., Esterle, J., Patra, S., Dirghangi, S.S., 2018. Petrographic and Raman spectroscopic characterization of coal from Himalayan fold-thrust belts of Sikkim, India. International Journal of Coal Geology 196, 246-259.


The present study focuses on the investigation of the optical anisotropy, optical sign, textural heterogeneity and deformational features of the maceral grains along with the Raman spectral characteristics of the seven coal samples collected from the Himalayan fold-thrust belts of Sikkim State, India. The coal samples were extremely fragile and pulverized due to the intense tectonic

deformation. The maceral composition revealed the dominance of semifusinite over collotelinite grains. The calculated maximum vitrinite reflectance (5.94–8.66%) and mean random reflectance (4.11–5.36%) suggest anthracite A rank of the coal samples following ISO 11760:2005. The proximity of the intermediate reflectance axis value (RINT) to maximum reflectance axis value (RMAX) as well as the range of Reflectance Indicating Surface (RIS) style (Rst) values (−9.98 to −19.37) indicates the biaxial negative optical texture of the vitrinite grains. The augmented bireflectance values due to enhancement of the RMAX associated with strong decline in RMIN may suggest the commencement of pregraphitization. In addition, the strong linear correlation (r = 0.94) of the RIS-anisotropy (Ram) parameter with the bireflectance values may imply the role of tectonic stress on the optical transformations of the samples. The range of the peak temperature (334.94–369.01 °C) calculated from mean random vitrinite reflectance may suggest the effect of thermo-stress coupling on the metamorphism of these coal samples. Microlithotype study combined with deformational aspects of macerals shows the presence of “deformed”, “sheared” and “smashed” grains within each sample, which may, additionally, document the tectonic stress influence on the coal particles. Moreover, relatively, larger area of ‘defect band 1 (D1)’ than that of ‘graphitic band (G)’ along with the broad G band in the first order Raman spectra may indicate the considerable presence of structural dislocations and aromatic compounds with disordered bond angle within the microstructure induced by the tectonic deformation. The lowest intensity of the ‘defect band 4 (D4)’ may suggest the preferential removal of aliphatic compounds from the samples in response to the tectonic stress degradation. In addition, the relative area ratio calculated from the D1 and the G bands (AD1/(AD1 + AG)) may indicate that the studied anthracite samples would have attained the metamorphic temperature ranging from 325.12–387.89 °C.

Ghuneim, L.-A.J., Jones, D.L., Golyshin, P.N., Golyshina, O.V., 2018. Nano-sized and filterable bacteria and archaea: Biodiversity and function. Frontiers in Microbiology 9, 1971. doi: 10.3389/fmicb.2018.01971.


Nano-sized and filterable microorganisms are thought to represent the smallest living organisms on earth and are characterized by their small size (50–400 nm) and their ability to physically pass through <0.45 μm pore size filters. They appear to be ubiquitous in the biosphere and are present at high abundance across a diverse range of habitats including oceans, rivers, soils, and subterranean bedrock. Small-sized organisms are detected by culture-independent and culture-dependent approaches, with most remaining uncultured and uncharacterized at both metabolic and taxonomic levels. Consequently, their significance in ecological roles remain largely unknown. Successful isolation, however, has been achieved for some species (e.g., Nanoarchaeum equitans and “Candidatus Pelagibacter ubique”). In many instances, small-sized organisms exhibit a significant genome reduction and loss of essential metabolic pathways required for a free-living lifestyle, making their survival reliant on other microbial community members. In these cases, the nano-sized prokaryotes can only be co-cultured with their ‘hosts.’ This paper analyses the recent data on small-sized microorganisms in the context of their taxonomic diversity and potential functions in the environment.

Gill, F.L., Hummel, J., Sharifi, A.R., Lee, A.P., Lomax, B.H., 2018. Diets of giants: the nutritional value of sauropod diet during the Mesozoic. Palaeontology 61, 647-658.

https://doi.org/10.1111/pala.12385

A major uncertainty in estimating energy budgets and population densities of extinct animals is the carrying capacity of their ecosystems, constrained by net primary productivity (NPP) and its digestible energy content. The hypothesis that increases in NPP due to elevated atmospheric CO2 contributed to the unparalleled size of the sauropods has recently been rejected, based on modern studies on herbivorous insects that imply a general, negative correlation of diet quality and increasing CO2. However, the nutritional value of plants grown under elevated CO2 levels might be very different for vertebrate megaherbivores than for insects. Here we show plant species‐specific responses in metabolizable energy and nitrogen content, equivalent to a two‐fold variation in daily food intake estimates for a typical sauropod, for dinosaur food plant analogues grown under CO2 concentrations spanning estimates for Mesozoic atmospheric concentrations. Our results potentially rebut the hypothesis that constraints on sauropod diet quality were driven by Mesozoic CO2 concentration.



We report the results of simple experiments which support the hypothesis that changes in ocean chemistry beginning in the Mesozoic Era resulted in an increase in the nutritional quality per mole of C and per cell of planktonic algal biomass compared to earlier phytoplankton. We cultured a cyanobacterium, a diatom, a dinoflagellate, and a green alga in media mimicking aspects of the chemistry of Palaeozoic and Mesozoic‐Cenozoic oceans. Substantial differences emerged in the quality of algal biomass between the Palaeozoic and Mesozoic‐Cenozoic growth regimes; these differences were strongly affected by interspecific interactions (i.e., the co‐existence of different species alters responses to the chemistry of the medium). The change was in the direction of a Mesozoic‐Cenozoic biomass enriched in protein per mole C, although cells contained less carbon overall. This would lead to a lower C:N ratio. On the assumption that Mesozoic‐Cenozoic grazers’ assimilation of total C was similar to that of their earlier counterparts, their diet would be stoichiometrically closer to their C:N requirement. This, along with an increase in mean cell size among continental shelf phytoplankton, could have helped to facilitate observed evolutionary changes in the Mesozoic marine fauna. In turn, increased grazing pressure would have operated as a selective force for the radiation of phytoplankton clades better equipped with antigrazing capabilities (sensu lato), as found widely in phytoplankton with biomineralization. Our results emphasize potential links between changing seawater chemistry, increased predation pressure and the rise to ecological dominance of chlorophyll a+c algae in Mesozoic oceans. The experiments also suggest a potential role for ocean chemistry in changes of marine trophic structure from the Palaeozoic to the later Mesozoic Era.



This study reports an analytical approach by gas chromatography and high-resolution mass spectrometry (HRMS) intended to be used for investigation of non-targeted environmental contaminants in honeybees. The approach involves a generic extraction and analysis with two GC-HRMS systems: time-of-flight and Orbitrap analyzers, GC-TOF-MS, and GC-Orbitrap-MS operated in electron-impact ionization (EI) mode. The workflow for screening of non-targeted contaminants

consisted of initial peak detection by deconvolution and matching the first-stage mass spectra EI-MS with a nominal mass spectral library. To gain further confidence in the structural characterization of the contaminants under investigation, molecular formula of representative ions (molecular and fragment ions) was provided for those with an accurate mass scoring (error < 5 ppm). This methology was applied for screening environmental contaminants in 75 samples of adult honeybee. This approach has provided the tentative identification of environmental contaminants belonging to different chemical groups, among them, PAHs, phthalates and synthetic musks. Residues of veterinary treatments used in apiculture were also detected in the honeybee samples.

González Arismendi, G., Tappert, R., McKellar, R.C., Wolfe, A.P., Muehlenbachs, K., 2018. Deuterium exchangeability in modern and fossil plant resins. Geochimica et Cosmochimica Acta 239, 159-172.


Deuterium exchange experiments on modern and fossil plant resins (amber) were conducted to assess to what extent diagenetic alteration can overprint the stable hydrogen (δ2H) and carbon (δ13C) isotopic composition of these materials. Pairs of resins and amber fragments were placed together with deuterated water in sealed quartz-glass tubes to assure that all samples were exposed equally to the chosen experimental conditions. Experiments lasting up to one year were carried out at temperatures of 50 °C and 90 °C using water artificially enriched in deuterium (2H concentrations between 2861 and 8845 µg/g), which resulted in deuterium concentrations measured in samples well above natural concentrations (i.e., 2H ∼ 143 µg/g). Modern resins recorded a mean deuterium exchange with deuterium-enriched water of 2.0 ± 0.1%, compared to 1.3 ± 0.2% observed in their fossil counterparts. No significant changes were observed in the δ13C of modern and fossil resins during the experiments. Overall, these results indicate that the extent of 2H isotopic exchange in resins is minor and apparently occurs prior to polymerization. Consequently, the stable isotopic composition of fossil resins has the potential to serve as a useful proxy for paleoenvironmental reconstructions, given the widespread distribution of ambers in the Mesozoic and Cenozoic fossil record.

Goryl, M., Marynowski, L., Brocks, J.J., Bobrovskiy, I., Derkowski, A., 2018. Exceptional preservation of hopanoid and steroid biomarkers in Ediacaran sedimentary rocks of the East European Craton. Precambrian Research 316, 38-47.


Thermally unstable hopanes with a biological 17β,21β (H)- configuration (ββ hopanes), hopenes, hopanoic acids and hopanols were identified as important constituents of Ediacaran to Cambrian sedimentary rocks of the East European Craton. Relatively high abundances of ββ hopanes in relation to αβ hopanes were identified in the Petersburg area and eastern Belarus, while in Volyn samples these compounds were found in traces. In addition, polar hopanoids including hopanols and hopanoic acids were found in most of the Petersburg and some Belarus and Volyn sedimentary rocks. The estimated equivalent of vitrinite reflectance for samples of lower maturity, measured based on C31ββ/(αβS + αβR + ββ) ratio is in the range 0.28–0.49% Rr, while for those of higher thermal maturity this parameter corresponds to 0.41–0.57% Rr. The values of the C31 22S/(S + R) ratio are in agreement with above data and are in the range of 0.1–0.3 for the Belarus and Petersburg samples, of 0.3–0.4 for Volyn, and of 0.4–0.5 for Lithuania, where ββ hopanes and hopanols were not detected or are present as traces. Moreover, there is good correlation (R2 = 0.8) between C31ββ/(αβS + αβR + ββ) and C31ENE/(H + ENE) ratio values (defined as ratio of C31 hopenes to αβ hopanes), which proves that less-stable ββ hopanes and hopenes are enriched in the same immature sedimentary rocks. The remarkable occurrence of a significant portion of sedimentary hopanes retaining the biological

stereochemical configuration confirms that exceptionally immature Precambrian rocks can be found in some instances when these strata have undergone only a mild burial temperature history.

Greco, E., El-Aguizy, O., Ali, M.F., Foti, S., Cunsolo, V., Saletti, R., Ciliberto, E., 2018. Proteomic analyses on an ancient Egyptian cheese and biomolecular evidence of Brucellosis. Analytical Chemistry 90, 9673-9676.


The material analyzed in this study is probably the most ancient archeological solid residue of cheese ever found to date. The sample was collected during the Saqqara Cairo University excavations in the tomb of Ptahmes dated to XIX dynasty (El-Aguizy, O. Bulletin de l'Institut Française d'Archéologie Orientale (BIFAO) 2010, 110, 13−34; Staring, N. Bulletin de Institut Français d'Archéologie Orientale (BIFAO) 2015, 114, 455–518). Our biomolecular proteomic characterization of this archeological sample shows that the constituting material was a dairy product obtained by mixing sheep/goat and cow milk. The interactions for thousands of years with the strong alkaline environment of the incorporating soil rich in sodium carbonate and the desertic conditions did not prevent the identification of specific peptide markers which showed high stability under these stressing conditions. Moreover, the presence of Brucella melitensis has been attested by specific peptide providing a reasonable direct biomolecular evidence of the presence of this infection in the Ramesside period for which only indirect paleopathological evidence has been so far provided (Pappas, G.; Papadimitriou P. Int. J. Antimicrob. Agents 2007, 30, 29−31; Bourke, J. B. Medical History 1971, 15 (4), 363–375). Finally, it is worth noting that, although proteomic approaches are successfully and regularly used to characterize modern biological samples (D’Ambrosio, C.; Arena, S.; Salzano, A. M.; Renzone, G.; Ledda, L.; and Scaloni, A. Proteomics 2008 8, 3657−3666, their application in ancient materials is still at an early stage of progress, only few results being reported about ancient food samples (Yang, Y.; Shevchenko, A.; Knaust, A.; Abuduresule, I.; Li, W.; Hu, X.; Wang, C.; Shevchenko, A. J. Archaeol. Sci. 2014, 45, 178−186. In the absence of previous relevant evidence of cheese production and/or use, this study, undoubtedly has a clear added value in different fields of knowledge ranging from archaeometry, anthropology, archeology, medicine history to the forensic sciences.

Greenfield, L.M., Hill, P.W., Paterson, E., Baggs, E.M., Jones, D.L., 2018. Methodological bias associated with soluble protein recovery from soil. Scientific Reports 8, Article 11186.

https://doi.org/10.1038/s41598-018-29559-4

Proteins play a crucial role in many soil processes, however, standardised methods to extract soluble protein from soil are lacking. The aim of this study was to compare the ability of different extractants to quantify the recovery of soluble proteins from three soil types (Cambisol, Ferralsol and Histosol) with contrasting clay and organic matter contents. Known amounts of plant-derived 14C-labelled soluble proteins were incubated with soil and then extracted with solutions of contrasting pH, concentration and polarity. Protein recovery proved highly solvent and soil dependent (Histosol > Cambisol > Ferralsol) and no single extractant was capable of complete protein recovery. In comparison to deionised water (10–60% of the total protein recovered), maximal recovery was observed with NaOH (0.1 M; 61–80%) and Na-pyrophosphate (0.05 M, pH 7.0; 45–75% recovery). We conclude that the dependence of protein recovery on both extractant and soil type prevents direct comparison of studies using different recovery methods, particularly if no extraction controls are used. We present recommendations for a standard protein extraction protocol.

Grégoire, B., Greenwell, H.C., Fraser, D.G., 2018. Peptide formation on layered mineral surfaces: The key role of brucite-like minerals on the enhanced formation of alanine dipeptides. ACS Earth and Space Chemistry 2, 852-862.


Alkaline hydrothermal vent environments have gained much attention as potential sites for abiotic synthesis of a range of organic molecules. However, the key process of peptide formation has generally been undertaken at lower pH and using dissolved copper ions to enhance selectivity and reactivity. Here, we explore whether layered precipitate minerals, abundant at alkaline hydrothermal systems, can promote peptide bond formation for surface-bound alanine under cycles of wetting and drying. While we find low level activity in brucite and binary layered double hydroxide carbonate minerals (typically <0.1% yield), the inclusion of structural copper to form a ternary layered double hydroxide mineral significantly increased the yield to >7%. However, the performance decreased over successive wetting/drying cycles. Control experiments show that this high degree of dipeptide formation cannot be attributed to leached copper from the mineral structure. While only dipeptides are observed, the yields obtained suggest that such processes, if occurring on the early Earth, could have added to the pool of available biological building units.

Griffin, C.G., Finlay, J.C., Brezonik, P.L., Olmanson, L., Hozalski, R.M., 2018. Limitations on using CDOM as a proxy for DOC in temperate lakes. Water Research 144, 719-727.


Colored dissolved organic matter (CDOM) has been widely studied as part of efforts to improve understanding of the aquatic carbon cycle, by laboratory, in situ, and remote sensing methods. We studied ecoregion-scale differences in CDOM and dissolved organic carbon (DOC) to understand variability in organic matter composition and the use of CDOM as a proxy for DOC. Data from 299 lakes across the U.S. Upper Midwest showed that CDOM, measured as absorptivity at 440 nm (a440), correlated strongly with DOC (R2 = 0.81, n = 412). Colored lakes in the Northern Lakes and Forests (NLF) ecoregion drove this relationship. Lakes in the North Central Hardwood Forests (NCHF) had low color (most had a440 < 3 m−1) and weaker CDOM-DOC relationships (R2 = 0.47). Spectral slopes and specific ultraviolet absorbance (SUVA), indicated relatively low aromaticity and non-terrestrial DOM sources in low color lakes. Multiple regression analyses that included total dissolved nitrogen (TDN) and CDOM, but not chlorophyll a, improved DOC estimates in low color lakes, suggesting a dominant contribution of non-planktonic sources of low color DOM in these lakes. Our results show that CDOM is a reliable, regional proxy for DOC in lakes where forests and wetlands dominate the landscape and the DOM is primarily terrestrial in origin. Mapping of lake DOC at broad spatial scales by satellite-derived CDOM has lower accuracy in low color lakes.

Groopman, E.E., Willingham, D.G., Meshik, A.P., Pravdivtseva, O.V., 2018. Discovery of fissionogenic Cs and Ba capture five years after Oklo reactor shutdown. Proceedings of the National Academy of Sciences 115, 8676-8681.


Significance: The Oklo natural nuclear reactors provide a wealth of information regarding the migration and retention of fission products in nuclear wastes. Radioactive volatile and gaseous elements easily escape from reactor fuel into the environment without proper containment. Cesium, in particular, represents a significant environmental and health hazard. Here, we used an isotope

imaging system to identify the location of sequestered fissionogenic Cs and Ba in Oklo. Cesium and Ba were captured in Ru metal/sulfide aggregates shortly after reactor criticality ceased. These elements were otherwise nearly completely lost from the reactor. We have further discovered the most depleted natural U on Earth, indicating that these fission products were retained in the most active region of the reactor.

Abstract: Understanding the release and sequestration of specific radioactive signatures into the environment is of extreme importance for long-term nuclear waste storage and reactor accident mitigation. Recent accidents at the Fukushima and Chernobyl nuclear reactors released radioactive 137Cs and 134Cs into the environment, the former of which is still live today. We have studied the migration of fission products in the Oklo natural nuclear reactor using an isotope imaging capability, the NAval Ultra-Trace Isotope Laboratory’s Universal Spectrometer (NAUTILUS) at the US Naval Research Laboratory. In Oklo reactor zone (RZ) 13, we have identified the most depleted natural U of any known material with a 235U/238U ratio of 0.3655 ± 0.0007% (2σ). This sample contains the most extreme natural burnup in 149Sm, 151Eu, 155Gd, and 157Gd, which demonstrates that it was sourced from the most active Oklo reactor region. We have discovered that fissionogenic Cs and Ba were captured by Ru metal/sulfide aggregates shortly following reactor shutdown. Isochrons from the Ru aggregates place their closure time at 4.98 ± 0.56 y after the end of criticality. Most fissionogenic 135Ba and 137Ba in the Ru migrated and was incorporated as Cs over this period. Excesses in 134Ba in the Ru point to the burnup of 133Cs. Cesium and Ba were retained in the Ru despite local volcanic activity since the reactor shutdown and the high level of activity during reactor operation.


https://doi.org/10.1038/s41396-018-0197-7

Coral reef ecosystems are highly sensitive to microbial activities that result from dissolved organic matter (DOM) enrichment of their surrounding seawater. However, the response to particulate organic matter (POM) enrichment is less studied. In a microcosm experiment, we tested the response of bacterioplankton to a pulse of POM from the mass-spawning of Orbicella franksi coral off the Caribbean coast of Panama. Particulate organic carbon (POC), a proxy measurement for POM, increased by 40-fold in seawater samples collected during spawning; 68% degraded within 66 h. The elevation of multiple hydrolases presumably solubilized the spawn-derived POM into DOM. A carbon budget constructed for the 275 µM of degraded POC showed negligible change to the concentration of dissolved organic carbon (DOC), indicating that the DOM was readily utilized. Fourier transform ion cyclotron resonance mass spectrometry shows that the DOM pool became enriched with heteroatom-containing molecules, a trend that suggests microbial alteration of organic matter. Our sensitivity analysis demonstrates that bacterial carbon demand could have accounted for a large proportion of the POC degradation. Further, using bromodeoxyuridine immunocapture in combination with 454 pyrosequencing of the 16S ribosomal RNA gene, we surmise that actively growing bacterial groups were the primary degraders. We conclude that coral gametes are highly labile to bacteria and that such large capacity for bacterial degradation and alteration of organic matter has implications for coral reef health and coastal marine biogeochemistry.

Guo, B., Shao, L., Hilton, J., Wang, S., Zhang, L., 2018. Sequence stratigraphic interpretation of peatland evolution in thick coal seams: Examples from Yimin Formation (Early Cretaceous), Hailaer Basin, China. International Journal of Coal Geology 196, 211-231.


Peat formed in mire settings sensitively records environmental fluctuations during deposition including changes in water table or base level and accommodation. On this basis coal seams, as geologically preserved peats, can provide evidence of high-resolution paleoclimatic fluctuations as well as paleobotanical evolution through periods of peat-formation. The No. 2 and No.1 (in ascending order) thick coal seams from the Early Cretaceous Yimin Formation in the Zhalainuoer Coalfield (Hailaer Basin, NE China) are investigated using sedimentological, sequence stratigraphic and petrographic analyses to understand the evolution of their peat forming environments. These ‘single’ thick coal seams, lacking siliciclasitic partings, are well-developed in the central area of the Zhalainuoer coalfield. Petrographic analyses demonstrate that water-table or base-level fluctuations in ‘single’ seams can be revealed by a number of significant surfaces formed by various events including paludification, give-up transgressive, accommodation reversal, flooding, and exposure surfaces. These surfaces can separate the single coal into a number of “wetting-up” and “drying-up” cycles. The wetting-up cycle is characterized by a gradual upward increasing trend in the huminite:inertinite ratio and in the ash yields. In contrast, the rapid drying-up cycle is characterized by an upward-increasing trend in the inertinite-dominated coal (46% on average) that represents a phase of exposure and oxidation resulting from a falling water table. This drying-up cycle can be correlated with the scouring surface in landward parts of the basin and terrestrialization surface basinward. The No. 2 coal seam occurs in the transgressive systems tract and comprises three high-frequency depositional sequences in which each coal cycle is characterized by a gradual wetting-up cycle and ends with a rapid drying-up cycle. The No. 1 coal seam occurs in the highstand system tract and consists of several high-frequency depositional sequences in which each coal cycle is characterized by a gradual drying-up cycle and ends with a rapid wetting-up cycle. These coals could also superpose to constitute the thick coal seam in which various sequence-stratigraphic surfaces can be recognized including terrestrialization, accommodation reversal and exposure surfaces. Stratigraphic relationships between coal and clastic components in the Yimin Formation enable us to demonstrate that thick coals span the formation of several coal cycles and high-resolution boundaries, allowing us to interpret the effects of accommodation on coal seam composition. Recognition that environmental changes can be recorded by thick coals has significance for studies that incorrectly suppose that peat or coal cycles can offer high-resolution and time-invariant records of paleoclimatic fluctuations and paleobotany evolution.

Guo, W., Li, B., Chi, H., Ramsey, E.D., 2018. A dedicated mass spectrometer tuning method for SFC–MS and evaluation of two different linear restrictor types used in the operation of a split flow pre-back pressure regulator SFC–MS interface. Chromatographia 81, 1257-1267.

https://doi.org/10.1007/s10337-018-3565-6

The operation of a SFC–MS system has been improved. The SFC–MS interface uses a post-column make-up flow of liquid whose supply line to the SFC–MS interface mixing tee is equipped with an injection valve. Prior to analysis, this arrangement permits a stable flow of a dilute tune solution of analyte(s) for the exact amount of time required to optimize mass spectrometry tuning. Advantageously, with this arrangement tuning is performed in the presence of the exact split flow and same composition of SFC mobile phase and make-up liquid to be used for subsequent SFC–MS operation. The SFC–MS interface was constructed to provide a pre-back pressure regulator split flow to the mass spectrometer using a linear restrictor. Two different linear restrictors constructed from either 50 µm i.d. PEEK tubing or 25 µm i.d. fused silica tubing were evaluated. For best electrospray performance, each restrictor required a different post-column make-up flow rate. The use of either restrictor retained a high degree of chromatographic fidelity for the SFC separation of six pharmaceutical compounds using a cyanopropyl column with a mobile phase of supercritical fluid

carbon dioxide modified with methanol and aqueous ammonia solution. Each restrictor provided a different level of SFC–MS performance for each of the six pharmaceutical compounds tested. Based upon overall performance, a linear fused silica restrictor was selected to develop a chromatographic separation using on-line SFC–MS for three structurally very similar monensin sodium salt analogues that are not directly amenable to off-line SFC using UV/Vis detection.

Gupta, I., Rai, C., Sondergeld, C.H., Devegowda, D., 2018. Rock typing in Eagle Ford, Barnett, and Woodford formations. SPE Reservoir Evaluation & Engineering 21, 654-670.

https://doi.org/10.2118/189968-PA

Shales are the most commonly found sedimentary rocks on Earth. Most US shale plays are massive, with different maturity regions and varying prospects. There has been a paradigm shift in the understanding of shale anisotropy and microstructures in the last decade, with a high focus on the identification of sweet spots and optimal reservoir-quality zones. Rock typing is one of the sought-after techniques to achieve this objective, and it has become an integrated part of the unconventional-characterization work flow. In this work, rock typing was performed with an integrated work flow using laboratory petrophysical measurements. The rock types were derived with machine-learning clustering algorithms—namely, K-means and self-organizing maps (SOM). The integrated work flow was applied in three different shale plays: Eagle Ford, Barnett, and Woodford. Three different rock types were identified. In general, Rock Type 1 had the highest porosity and total organic carbon (TOC), indicative of highest storage and source-rock potential, respectively. Rock Type 1 was also the key rock type controlling the production. Rock Type 2 had intermediate porosity and TOC, whereas Rock Type 3 had the lowest porosity and TOC. Next, core-derived rock types had to be scaled up to logs. Support vector machines (SVM), a classification algorithm, was used for scaling up. It was trained with a data set consisting of depths at which both core and log data were available. Different logs such as gamma ray, resistivity, neutron, and density were used for scaling up. Finally, a rock-type ratio (RTR) was defined from rock-type logs based on fraction of Rock Type 1 over gross thickness. The ratio thus developed was found to have a strong correlation with normalized oil-equivalent production rate. In total, 22 wells with core data were considered for rock typing in the three shale plays. The rock types were scaled up to 95 wells at a cumulative over a 20,000-ft depth interval. The work flow shown in this paper can easily be extended to other data sets in other plays. The manual approach, on the other hand, can be prohibitively time-consuming.

Guzman, M., McKay, C.P., Quinn, R.C., Szopa, C., Davila, A.F., Navarro-González, R., Freissinet, C., 2018. Identification of chlorobenzene in the Viking gas chromatograph-mass spectrometer data sets: Reanalysis of Viking Mission data consistent with aromatic organic compounds on Mars. Journal of Geophysical Research: Planets 123, 1674-1683.

https://doi.org/10.1029/2018JE005544

Abstract: Motivated by the recent detection of chlorobenzene by the Sample Analysis at Mars instrument suite on the Curiosity rover, and the identification of its carbon source as indigenous to the martian sample, we reexamined the original, microfilm preserved, Viking gas chromatograph‐mass spectrometer data sets. We found evidence for the presence of chlorobenzene in Viking Lander 2 (VL‐2) data at levels corresponding to 0.08–1.0 ppb (relative to sample mass), in runs when the sample was heated to 350°C and 500°C. Additionally, we found a correlation between the temperature dependence of the chlorobenzene signal and the dichloromethane signal originally identified by the Viking gas chromatograph‐mass spectrometer team. We considered possible sources of carbon that may have produced the chlorobenzene signal, by reaction with perchlorate during

pyrolysis, including organic carbon indigenous to the martian parent sample and instrument contamination. We conclude that the chlorobenzene signal measured by VL‐2 originated from martian chlorine sources. We show how the carbon source could originate from the martian parent sample, though a carbon source contributed from instrument background cannot yet be ruled out.

Plain Language Summary: The first successful landers on Mars were the twin Viking spacecraft in 1976. Their primary goal was to determine if life could survive on Mars. The Viking landers looked for organic matter in the martian soil. Organics are critical for astrobiology since carbon forms the key ingrediant for all known living organisms on Earth. Shockingly, a main instrument on the landers, the gas chromatograph‐mass spectrometer, detected no organic matter. This was a surprise to scientists, who knew organic material was deposited by comets and meteorites to the martian surface. The apparent absence of organic molecules in the martian surface material became a scientific mystery for decades. In 2008, the Phoenix spacecraft explored the north pole of Mars. Phoenix discovered a salt in the martian soil which is rare on Earth. After further conclusions of the presence of this salt on Mars and complemental experiments on Earth, scientists proposed this salt might have chlorinated any organics inside the Viking instruments. We searched the Viking data for a possible reaction product between the salt and organics in the Viking oven, chlorobenzene, a chlorinated organic molecule. We found evidence of chlorobenzene. We conclude the chlorine component of the chlorobenzene is martian, and the carbon molecule of the chlorobenzene is consistent with a martian origin, though we cannot fully rule out instrument contamination.

Hackley, P.C., Valentine, B.J., Hatcherian, J.J., 2018. On the petrographic distinction of bituminite from solid bitumen in immature to early mature source rocks. International Journal of Coal Geology 196, 232-245.


The oil-prone maceral bituminite (and its equivalents: ‘amorphous organic matter’, ‘sapropelinite’, ‘amorphinite’, etc.) converts to petroleum during thermal maturation of source rocks, resulting in formation of a mobile saturate-rich hydrocarbon and a polar-rich residue of solid bitumen. Evidence of this transition is preserved in immature to early mature source rocks (e.g., Alum, Bakken, Kimmeridge, New Albany, Ohio shales, among many others), where organic petrography reveals a continuum of textures, reflectance, and fluorescence intensity occurring between bituminite and solid bitumen. Bituminite generally is characterized by high(er) intensity fluorescence, low contrast to the inorganic matrix, lower reflectance (compared to solid bitumen), and heterogeneous wispy or ‘schlieren’ textures. In comparison, solid bitumen generally shows lower intensity or no fluorescence compared to bituminite, a distinct contrast to the mineral matrix which usually includes a gray homogeneous surface of low to moderate reflectance, and may possess void-filling, embayment or groundmass textures suggesting evidence of migration or its in situ exsolution. However, these properties may manifest across a continuous spectrum in a sample or in a single microscope field, often making identification inconclusive. Unambiguous identification is further hampered by sample preparation, e.g., mechanical polish may improve homogeneity of larger accumulations, whereas smaller accumulations, or those sheltered by hard minerals, may appear more heterogeneous, leading to identification of the same organic matter as solid bitumen or bituminite, respectively. The disruptive innovation of ion milling in shale sample preparation leads to increased organic reflectance and surface homogeneity, causing bituminite and other oil-prone macerals, e.g., alginite, to develop a gray reflecting surface which is easy to confuse with solid bitumen, especially when obvious void-filling or embayment textures of the latter are absent. Herein we review distinction of solid bitumen from bituminite and alginite in immature to early mature source rocks, providing examples from nine samples illustrated by typical organic petrography images, including samples from hydrous pyrolysis experiments. Based on a review of the literature, we observe an arbitrary reflectance limit of 0.30% in

mechanically polished samples seems to differentiate bituminite (<0.30%) from confident identifications of homogeneous solid bitumen (which otherwise lacks obvious void-filling or identifying embayment textures) as individual macerals on a continuous spectrum in immature and early mature source rocks. Future work conducted by governing bodies such as the International Committee for Coal and Organic Petrology (ICCP) should consider interlaboratory studies conducted on multiple immature source rock samples to develop consensus guidelines for bituminite and solid bitumen discrimination.

Han, S., Zhang, J., Horsfield, B., Wang, C., 2018. Shale oil and gas generating characteristics of lacustrine Shahejie Formation in eastern sag of Liaohe depression, Northeast China. International Journal of Oil, Gas and Coal Technology 19, 83-96.

http://dx.doi.org/10.1504/IJOGCT.2018.10014800

As a known source of commercial oil and gas in the Liaohe depression, the lacustrine Shahejie Shale formation is a target of unconventional petroleum exploration. Characterising hydrocarbon generating and phase behaviour evolution is considered to be an empirical method or a prerequisite in resource evaluation and economic estimation. However, this is poorly understood on the lacustrine Shahejie Shale formation as a candidate for shale oil/gas play. According to kinetics of hydrocarbon generation, in this study the source rock potential and physical properties of generated fluids are analysed. Furthermore, this research provides a case study relating experimental data obtained on samples with modelling results. Samples from different wells that represent a range of maturation levels and lithofacies are discussed in this paper.



The geochemical characteristics of natural gases from Lower Paleozoic Jingbian gas field are abnormal and the carbon isotope of most natural gases has reversed, which led to a dispute over the source of natural gas in the Lower Paleozoic. The Upper Paleozoic Yulin gas field is adjacent to the Jingbian gas field, but the geochemical characteristics of the Yulin gas field did not appear abnormal. Besides, the ethane carbon isotope of Upper Paleozoic Yulin gas field is much higher than that of Lower Paleozoic Jingbian gas field. In order to identify the reasons for the carbon isotope reversal of natural gas in Lower Paleozoic Jingbian gas field and its relationship with natural gas source, We conducted the components and stable carbon isotopes of natural gas from Upper Paleozoic Yulin gas field and Lower Paleozoic Jingbian gas field. On the basis of these experiments, we compared the natural gas components and carbon isotope of 100 samples from both Upper Paleozoic Yulin gas field and Lower Paleozoic Jingbian gas field. The results indicate that higher maturity will break the conventional rule, when maturity reaches a certain threshold; δ13Cethane value will decrease with maturity. Although δ13Cmethane value will also increase with maturity, the extent will be relatively smaller. This leads to unusual δ13Cmethane > δ13Cethane in the region with higher maturity. In the process of downward migration of coal-derived gas from Carboniferous-Permian coal measures, component fractionation and carbon isotope fractionation might occur, resulting the ethane components and carbon isotope value of Lower Paleozoic less than those of Upper Paleozoic, which will lead to the carbon isotope reversal. The mixing of oil-derived gas and coal-derived gas at different ratios may also lead to the reversal of carbon isotopes. The natural gas types of Jingbian gas field are mainly

coal-derived gas generated from Carboniferous-Permian coal measure strata, with a small amount of oil-derived gas generated from Carboniferous-Permian marine-terrigenous limestone.

Han, Y., Poetz, S., Mahlstedt, N., Karger, C., Horsfield, B., 2018. Fractionation and origin of NyOx and Ox

compounds in the Barnett Shale sequence of the Marathon 1 Mesquite well, Texas. Marine and Petroleum Geology 97, 517-524.


We have previously reported the origin and fractionation of pyrrolic nitrogen-containing compounds (Ny) during the primary migration of oil within the Barnett Shale sequence of the Marathon 1 Mesquite Well, Texas. Here, we provide insights into the oxygen-containing NyOx and Ox compounds. In negative-ion electrospray (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), Ny and NyOx are the predominant elemental species, and the remaining Ox, SzOx, Sz, NySz and OxNySz compounds are generally less than 5% relative to the total monoisotopic ion abundance (TMIA). In contrast to Ny compounds, which were preferentially retained in source rocks during expulsion, the NyOx compounds were selectively expelled out of source rocks. Among the NyOx compounds, N1O1, N1O2, and N2O1 are the dominant species, which exhibit different fractionation effects. Despite this observation, very similar carbon number (CN) distributions were illustrated, i.e., the predominance of C0-5 alkylated homologues maximizing at C2 or C3 substitutes. Additionally, all NyOx compounds fall in the range of 10–30 DBE (double bond equivalents), with the major classes illustrating an interval of three DBE units. Notably, this is also the case for Ny compounds. The overall similar distributions of CN and DBE suggest that Ny and NyOx compounds have restricted precursors and common mechanisms of formation. Nonfluorescent chlorophyll catabolites (NCCs), the final breakdown products of chlorophyll, were tentatively proposed as possible precursors. For Ox compounds, O2 is the dominant species spread over a DBE range of 1–17, with a maximum at 1 DBE class. The predominance of even-carbon-number molecules, particularly C16H32O2 and C18H36O2, suggests the possible origin of O2 compounds with 1 DBE from fatty acids.

Hao, D., Zhang, L., Ye, Z., Tu, S., Zhang, C., 2018. Experimental study on the effects of the moisture content of bituminous coal on its gas seepage characteristics. Arabian Journal of Geosciences 11, Article 436.

https://doi.org/10.1007/s12517-018-3758-1

Moisture content is the main factor affecting the occurrence and flow of gas in bituminous coal and restricts the gas permeability of the coal seam, which affects the effectiveness of gas extraction from the coal seam directly. In order to study the influence of moisture content on the gas seepage characteristics of bituminous coal, this paper focused on bituminous coal from the Xutuan coal mine and used a bespoke laboratory unit called a Gas Flow and Displacement Testing Apparatus (GFDTA). The moisture content of bituminous coal was measured, and the axial and radial gas seepage experiments of bituminous coal under different moisture content conditions were carried out. The average original moisture content (1.3%) and the average saturated moisture content (2.4%) of the bituminous coal sample were obtained. It was observed that, with the increase of time, the original moisture content of the coal decreased with a negative exponential function and the wetting moisture content increased with an Exponential Association function. The gas axial seepage experimental results showed that when the moisture content was lower, the coal adsorbed CH4; when the moisture content was higher than Mad, the two fields of gas and liquid are coupled and affect the axial flow of the CH4, decreasing the moisture content. With higher moisture content, the interaction between the two is more readily evident and the diffusion behavior of the CH4 has a greater impact on the

moisture content. Axial and radial gas seepage experiments, under the same gas pressure, axial pressure, and confining pressure, revealed that with the increase of moisture content, the axial and radial permeability of bituminous coal first increased and then decreased. This phenomenon is analyzed by the water lock effect, the effects of sorption on gas seepage and moisture content on gas adsorption effects. Among them, critical moisture content of approximately 1% exists when the axial and confining pressures are loaded or unloaded at the same time as well as the axial pressure loading or unloading alone. However, the critical moisture content is about 0.5% under confining pressure loading or unloading alone. In addition, in radial seepage experiments, it was observed that the volumetric strain of the coal decreased with the increase in the moisture content.



A novel type of solid-shelled microspheres was prepared by emulsion templating technique through layer-by-layer self assembly. The regulation controlled by different payloads, surfactants, 3-aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS) ratio produced three solid-shelled microspheres with various morphology, sizes, shell thicknesses and brittleness. Such microspheres can be considered as diluent-loaded eggs that can be cracked when forced between narrow rock surfaces or against blocking fluid flow particles. The structural characteristics, size distribution, stability, breakable and release behavior of three payload-in-silica microspheres were investigated by optical microscopy techniques and scanning electron microscopy (SEM) technique, dynamic light scattering (DLS), zeta potential, and ultraviolet-visible (UV–vis) spectroscopy. The results indicated that these three microspheres were relatively uniform in size (1–5 μm) and had a smooth surface with shell thicknesses of 40–120 nm, which also possessed excellent stability. Yet the brittleness of silica shell was obviously different for three solid-shelled microspheres, in detail, the silica shell of toluene microspheres was more brittle and easier to be ruptured than hexane microspheres under external hydrodynamics forces. Sand column tests revealed that the easy-broken toluene-in-silica microspheres prepared from tween-80 template matched the pore throat of reservoir better and achieved higher heavy oil recovery efficiency (94.60%). Such breakable microspheres can provide a selective and targeted diluting approach to extract blockages by heavy-oil and asphaltene precipitates.

Hardisty, D.S., Lyons, T.W., Riedinger, N., Isson, T.T., Owens, J.D., Aller, R.C., Rye, D.M., Planavsky, N.J., Reinhard, C.T., Gill, B.C., Masterson, A.L., Asael, D., Johnston, D.T., 2018. An evaluation of sedimentary molybdenum and iron as proxies for pore fluid paleoredox conditions. American Journal of Science 318, 527-556.

http://www.ajsonline.org/content/318/5/527.abstract

Iron speciation and trace metal proxies are commonly applied together in efforts to identify anoxic settings marked by the presence of free sulfide (euxinia) or dissolved iron (ferruginous) in the water column. Here, we use a literature compilation from modern localities to provide a new empirical evaluation of coupled Fe speciation and Mo concentrations as a proxy for pore water sulfide accumulation at non-euxinic localities. We also present new Fe speciation, Mo concentration, and S isotope data from the Friends of Anoxic Mud (FOAM) site in Long Island Sound, which is marked by pore water sulfide accumulation of up to 3 mM beneath oxygen-containing bottom waters. For the operationally defined Fe speciation scheme, ‘highly reactive’ Fe (FeHR) is the sum of pyritized Fe (Fepy) and Fe dominantly present in oxide phases that is available to react with pore water sulfide to

form pyrite. Observations from FOAM and elsewhere confirm that Fepy/FeHR from non-euxinic sites is a generally reliable indicator of pore fluid redox, particularly the presence of pore water sulfide. Molybdenum (Mo) concentration data for anoxic continental margin sediments underlying oxic waters but with sulfidic pore fluids typically show authigenic Mo enrichments (2–25 ppm) that are elevated relative to the upper crust (1–2 ppm). However, compilations of Mo concentrations comparing sediments with and without sulfidic pore fluids underlying oxic and low oxygen (non-euxinic) water columns expose non-unique ranges for each, exposing false positives and false negatives. False positives are most frequently found in sediments from low oxygen water columns (for example, Peru Margin), where Mo concentration ranges can also overlap with values commonly found in modern euxinic settings. FOAM represents an example of a false negative, where, despite elevated pore water sulfide concentrations and evidence for active Fe and Mn redox cycling in FOAM sediments, sedimentary Mo concentrations show a homogenous vertical profile across 50 cm depth at 1 to 2 ppm. A diagenetic model for Mo provides evidence that muted authigenic enrichments are derived from elevated sedimentation rates. Consideration of a range of additional parameters, most prominently pore water Mo concentration, can replicate the ranges of most sedimentary Mo concentrations observed in modern non-euxinic settings. Together, the modern Mo and Fe data compilations and diagenetic model provide a framework for identifying paleo-pore water sulfide accumulation in ancient settings and linked processes regulating seawater Mo and sulfate concentrations and delivery to sediments. Among other utilities, identifying ancient accumulation of sulfide in pore waters, particularly beneath oxic bottom waters, constrains the likelihood that those settings could have hosted organisms and ecosystems with thiotrophy at their foundations.

Harney, É., May, H., Shalem, D., Rohland, N., Mallick, S., Lazaridis, I., Sarig, R., Stewardson, K., Nordenfelt, S., Patterson, N., Hershkovitz, I., Reich, D., 2018. Ancient DNA from Chalcolithic Israel reveals the role of population mixture in cultural transformation. Nature Communications 9, Article 3336.

https://doi.org/10.1038/s41467-018-05649-9

The material culture of the Late Chalcolithic period in the southern Levant (4500–3900/3800 BCE) is qualitatively distinct from previous and subsequent periods. Here, to test the hypothesis that the advent and decline of this culture was influenced by movements of people, we generated genome-wide ancient DNA from 22 individuals from Peqi’in Cave, Israel. These individuals were part of a homogeneous population that can be modeled as deriving ~57% of its ancestry from groups related to those of the local Levant Neolithic, ~17% from groups related to those of the Iran Chalcolithic, and ~26% from groups related to those of the Anatolian Neolithic. The Peqi’in population also appears to have contributed differently to later Bronze Age groups, one of which we show cannot plausibly have descended from the same population as that of Peqi’in Cave. These results provide an example of how population movements propelled cultural changes in the deep past.

Hassanpour, S., Malayeri, M.R., Riazi, M., Mousavi, S.M., Negahban, Z., 2018. On the impact of Co3O4 nanoparticles on interaction of heavy oil and brine mixtures. Journal of Petroleum Science and Engineering 171, 680-686.


Among numerous EOR methods, the injection of brine with different salinities to oil reservoirs has gained attention where its performance would, in turn, depend on interfacial tension (IFT) of oil/brine mixture. The present study investigated the impact of Co3O4 nanoparticles with concentrations of 0.01, 0.1 and 1 wt% on IFT of brine solution (containing NaCl, KCl and CaCl2) and heavy crude oil

system. The results confirmed that adding Co3O4 nanoparticles to water, compared to that without nanoparticles, reduced IFT at low (i.e. 0–5000 ppm) and high (i.e. greater than 5000 ppm) brine concentrations, although the propensity of IFT is different for various concentrations. Furthermore, the reduction of IFT for monovalent ions is greater than that for divalent ions. Properties such as high surface activity and higher surface to volume ratio of the Co3O4 nanoparticles should be accounted for profound adsorption of asphaltene onto the surface of nanoparticles. A high suspension of asphaltene at the brine/oil interface also avoided its precipitation in oil causing IFT to reduce in brine/crude mixtures with nanoparticles compared to that without nanoparticles. The extent of IFT reduction changed by using different concentrations of Co3O4 nanoparticles. For the oil/brine system attempted in this study, the optimum concentration of Co3O4 nanoparticles in term of IFT reduction was 0.1 wt%.

Havelcová, M., Machovič, V., Sýkorová, I., Lapčák, L., Špaldoňová, A., Mach, K., Dvořák, Z., 2018. Duxite – Fossil resin of Miocene age. Organic Geochemistry 124, 190-204.


A series of Miocene fossil resin from the northwest part of the Czech Republic, called duxite, has been analyzed by elemental, microscopic, gas chromatography (GC/MS), pyrolysis-gas chromatography, Fourier Transform infrared (FTIR), and Raman techniques. The set of samples consisted of museum, contemporary and artificially altered samples. The results of GC/MS revealed fine variances in chemical structure among the samples, which could be attributed to the geologic paleosituation during resin deposition, as was verified by alteration of a sample under different conditions. Sesquiterpenes, including α-cedrene and cuparene, were identified in sample extracts and sample pyrolysates together with diterpenoid members abietanes, pimaranes, and dehydroabietanes. The distribution and intensity of functional groups of FTIR spectra also confirmed that the duxite samples were fossilised exudates from a member of the Cupressaceae conifer family. Raman spectra supported this record indicating aromatic character of duxite and higher maturity of the samples. The chemical composition indicated that duxite is a member of Class IV resins of the fossil resin classification system. Members of this group do not have a polymeric structure. This nonpolymerizable behaviour was confirmed by their excellent solubility in an organic solvent and the low softening point of the material. Our results therefore provide a valuable insight into the duxite-producing process and its potential for evaluating the geological environment and diagenetic conditions.

Hazra, B., Wood, D.A., Vishal, V., Singh, A.K., 2018. Pore characteristics of distinct thermally mature shales: Influence of particle size on low-pressure CO2 and N2 adsorption. Energy & Fuels 32, 8175–8186.


The influence of crushed sample particle size on low-pressure gas adsorption and desorption behavior of shales and their measurement is an issue of significant current interest in this new era focused on shale gas and oil resources. Here we study two samples of distinct Indian shales, with different organic contents, ages, levels of thermal maturity, and pore-size distributions crushed to four different particle size ranges [S1 (1 mm to 500 μm), S2 (500–212 μm), S3 (212–75 μm), and S4 (75–53 μm)]. Low-pressure gas adsorption analysis with nitrogen and carbon dioxide gases reveals significant and complex impacts of particle-crush sizes on the measured pore structure characteristics for the two shales. The CO2 results suggest that at the smallest (S4) particle-crush size evaluated, low-pressure gas adsorption measurements record more, finer nanopores (i.e., less than about 8 Å), fewer larger

nanopores (i.e., greater than about 8 Å), and a lower overall nanopore surface volume. The N2 results show an overall increase in macro-pore volume at the smallest particle-crush size. The results imply that while more, smaller pores are exposed to gas adsorption at the smaller crush sizes, a significant number of nanopores are in some way altered and are not recorded as part of the measured nanopore-size distribution >8 Å by low-pressure CO2 adsorption analysis. Fractal dimensions of one shale varied across a range of particle-crush sizes, whereas the fractal dimensions of the other shale studied did not. The analyses suggest that low-pressure gas adsorption results conducted with samples of very small particle-crush sizes should be viewed with caution.



The hydrogen isotopic composition of fatty acids (FAs) has previously been shown to reflect the metabolism of microorganisms in pure culture, but has rarely been tested in the environment. Here, we report the abundance and hydrogen isotopic composition of polar lipid derived FAs extracted from surface sediments of the saline Lake Grevelingen (The Netherlands), at two different stations and during two seasons with oxic bottom water conditions during spring and hypoxic to anoxic conditions during late summer. These data are compared with the bacterial diversity revealed by 16S rRNA gene amplicon sequencing. All measured FAs were depleted in deuterium relative to the bottom water by 103‰ to 267‰. FAs associated with heterotrophic bacteria (i-15:0 and ai-15:0) showed the smallest fractionation (−103‰ to −185‰) while those derived from pelagic photoautotrophic phytoplankton (20:5) showed the largest fractionation (−230‰ to −267‰). Overall, the hydrogen isotope fractionation reflected in the majority of the more commonly occurring FAs (14:0, 16:0, 16:1ω7) is relatively large (−172‰ to −217‰). Together with the high relative abundance of the 20:5 FA, this suggests a substantial contribution from dead pelagic biomass settling from the water column to the sedimentary polar lipid derived FA pool and not from the in situ microbial communities. Therefore, the majority of the isotope signal in the fatty acids from surface sediments might not represent the general metabolism of the active sedimentary communities. Therefore, the input of pelagic biomass into sedimentary environments may bias the information contained in the hydrogen isotopic composition of FAs.

Hermoso, M., Lecasble, M., 2018. The effect of salinity on the biogeochemistry of the coccolithophores with implications for coccolith-based isotopic proxies. Biogeosciences Discussions 2018.

https://doi.org/10.5194/bg-2018-357

Reconstruction of sea surface temperatures from the oxygen isotope composition (δ18O) of calcite biominerals synthesised in the mesopelagic zone of the oceans requires knowledge of the δ18O of seawater and constraints on the magnitude of biological 18O/16O fractionation (the so-called vital effect). In the palaeoceanography community, seawater δ18O and salinity are unduly treated as a common parameter owing to their strong co-variation both geographically and in the geological register. If the former parameter has arguably no notable influence on the biogeochemistry of marine calcifiers, salinity potentially does. However how salinity per se and the effect of osmotic adjustment can modulate the biogeochemistry, and in turn, the expression of the vital effect in calcite biomineral such as the coccoliths remains undocumented. In this culture-based study of coccolithophores (Haptophyta) belonging to the Noelaerhabdaceae family, we kept temperature and seawater δ18O

constant, and measured basic physiological parameters (growth rate and cell size), and the isotope composition (18O/16O and 13C/12C) of coccoliths grown under a range of salinity comprised between 29% and 39%. The overarching aim of this biogeochemical work has a geological finality and aims to refine the accuracy of palaeotemperature estimates using fossil coccoliths. We found that, although entailing large physiological changes in coccolithophores, salinity does not modulate biological fractionation in the oxygen isotope system. This is a contrasting observation with previous in vitro manipulations of temperature and carbonate chemistry that led to substantial changes in expression of the vital effect. As such, salinity is not a complicating factor to derive temperatures from coccolith-bearing pelagic sequences deposited during periods of change in ice volume, especially at the highest latitudes, or in coastal regions. By contrast, the carbon isotope composition of the coccoliths is influenced by a growth rate-mediated control of salinity with implications for deriving productivity indices from pelagic carbonate.

Holdridge, G., Leigh, D.S., 2018. Stable carbon analysis of alluvial paleosols in the Mixteca Alta, Oaxaca, Mexico. Quaternary International 490, 60-73.


We examine δ13C values from soil organic matter (SOM) from the Culebra, Inguiro and Verde watersheds (Verde data are from Mueller et al., 2012) located in the Mixteca Alta from the terminal Pleistocene to the present. The SOM δ13C values were compared against local paleosol data and other paleoenvironmental proxies from central and southwestern Mexico. The paleovegetation implications of the SOM reflect overall changes in paleoclimate from the terminal Pleistocene through the middle Holocene. The late Holocene stable carbon isotope values varied widely, suggesting that human activities such as agriculture affected the paleoenvironment and paleovegetation in the study area, similar to findings in central Mexico. Values of δ13C show a significant rise between 3500 cal BP and 1250 cal BP, with one notable cluster of enriched values corresponding to the Post-Classic cultural period (local Natividad phase, 1250–500 cal BP), when the local population is thought to have peaked over 100,000. Since the late Formative period (local late Cruz phase, starting ∼3500 cal BP), lama-bordo (i.e., sediment check-dams) and agricultural terrace constructions were important for land use management and agriculture, which became widespread by the Post-Classic period. The highly enriched values associated with widespread agricultural structures suggest the increased importance of maize cultivation, and potentially the increased significance of CAM plant management, such as maguey and nopal during the late Holocene.

Holzlechner, M., Bonta, M., Lohninger, H., Limbeck, A., Marchetti-Deschmann, M., 2018. Multisensor imaging—from sample preparation to integrated multimodal interpretation of LA-ICPMS and MALDI MS imaging data. Analytical Chemistry 90, 8831-8837.


Laterally resolved chemical analysis (chemical imaging) has increasingly attracted attention in the Life Sciences during the past years. While some developments have provided improvements in lateral resolution and speed of analysis, there is a trend toward the combination of two or more analysis techniques, so-called multisensor imaging, for providing deeper information into the biochemical processes within one sample. In this work, a human malignant pleural mesothelioma sample from a patient treated with cisplatin as a cytostatic agent has been analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). While LA-ICPMS was able to provide quantitative information on the platinum distribution along with the distribution of other elemental analytes in the tissue sample,

MALDI MS could reveal full information on lipid distributions, as both modes of polarity, negative and positive, were used for measurements. Tandem MS experiments verified the occurrence of distinct lipid classes. All imaging analyses were performed using a lateral resolution of 40 μm, providing information with excellent depth of details. By analyzing the very same tissue section, it was possible to perfectly correlate the obtained analyte distribution information in an evaluation approach comprising LA-ICPMS and MALDI MS data. Correlations between platinum, phosphorus, and lipid distributions were found by the use of advanced statistics. The present proof-of-principle study demonstrates the benefit of data combination for outcomes beyond one method imaging modality and highlights the value of advanced chemical imaging in the Life Sciences.

Hopwood, M.J., Carroll, D., Browning, T.J., Meire, L., Mortensen, J., Krisch, S., Achterberg, E.P., 2018. Non-linear response of summertime marine productivity to increased meltwater discharge around Greenland. Nature Communications 9, Article 3256.

https://doi.org/10.1038/s41467-018-05488-8

Runoff from the Greenland Ice Sheet (GrIS) is thought to enhance marine productivity by adding bioessential iron and silicic acid to coastal waters. However, experimental data suggest nitrate is the main summertime growth-limiting resource in regions affected by meltwater around Greenland. While meltwater contains low nitrate concentrations, subglacial discharge plumes from marine-terminating glaciers entrain large quantities of nitrate from deep seawater. Here, we characterize the nitrate fluxes that arise from entrainment of seawater within these plumes using a subglacial discharge plume model. The upwelled flux from 12 marine-terminating glaciers is estimated to be >1000% of the total nitrate flux from GrIS discharge. This plume upwelling effect is highly sensitive to the glacier grounding line depth. For a majority of Greenland’s marine-terminating glaciers nitrate fluxes will diminish as they retreat. This decline occurs even if discharge volume increases, resulting in a negative impact on nitrate availability and thus summertime marine productivity.

Hu, A., Guo, J.-J., Pan, H., Zuo, Z., 2018. Selective functionalization of methane, ethane, and higher alkanes by cerium photocatalysis. Science 361, 668-672.

http://science.sciencemag.org/content/361/6403/668.abstract

Astract: With the recent soaring production of natural gas, the use of methane and other light hydrocarbon feedstocks as starting materials in synthetic transformations is becoming increasingly economically attractive, although it remains chemically challenging. We report the development of photocatalytic C–H amination, alkylation, and arylation of methane, ethane, and higher alkanes under visible light irradiation at ambient temperature. High catalytic efficiency (turnover numbers up to 2900 for methane and 9700 for ethane) and selectivity were achieved using abundant, inexpensive cerium salts as photocatalysts. Ligand-to-metal charge transfer excitation generated alkoxy radicals from simple alcohols that in turn acted as hydrogen atom transfer catalysts. The mixed-phase gas/liquid reaction was adapted to continuous flow, enabling the efficient use of gaseous feedstocks in scalable photocatalytic transformations.

Editor's Summary: Radically transforming light hydrocarbons. Te methane, ethane, and propane in natural gas are mostly inert under ambient conditions. Mainly they are burned to produce heat. Hu et al. show that a simple cerium salt paired with an alcohol can catalytically transform these and other simple hydrocarbons into reactive radicals at room temperature (see the Perspective by Kanai). The reactions rely on light to photolytically cleave cerium alkoxide bonds, producing alkoxy radicals that

strip H atoms from the hydrocarbons and regenerate the alcohol. The resultant alkyl radicals readily add to azo compounds, olefins, and aromatics.

Huang, C., Yuan, X., Song, C., Yuan, J., Ni, X., Ma, X., Zhang, S., 2018. Characteristics, origin, and role of salt minerals in the process of hydrocarbon accumulation in the saline lacustrine basin of the Yingxi Area, Qaidam, China. Carbonates and Evaporites 33, 431-446.

https://doi.org/10.1007/s13146-017-0350-9

In recent years, an important discovery in exploration has been made in E23 of Oligocene in the Yingxi Area of the Western Qaidam Basin. Based on core observation, systemic microscopic characteristics analysis, mineralogy analysis and geochemical analysis, the mineral characteristics, origin, and role in the process of hydrocarbon accumulation in Oligocene in the saline lacustrine basin are systemically investigated in the Yingxi Area of the Qaidam Basin: (1) In this area, there are four important salt minerals: halite, gypsum, glauberite and celestite, which form saline layers with a certain thickness or develop in matrix carbonate rock in the form of mineral particles. In the upper reservoir group in the middle of saline layers, the saline layers are thicker, mainly rock salt, where thin oil layers are developed. In lower reservoir groups, the saline layers are thinner, mainly gypsum. (2) Salt minerals possess geochemical characteristics of “low content of Mn”. The matrix carbonate rock associated with salt minerals has “low temperature” carbon and oxygen isotope geochemical characteristics, and petrological characteristics without the hydrothermal minerals and distribution characteristics with a very wide range. All the above characteristics demonstrate that the salt minerals in this area are a typical deposition type in the saline lacustrine basin, and not a hydrothermal brine precipitation type. (3) “Salt” plays a critical role in the process of hydrocarbon accumulation. Salt minerals play the roles of crack-filling and sealing to prevent dissipation of oil and gas. In addition, salt layers play the role of sealing and covering due to high capillary breakthrough pressure and plastic characteristics. Salt minerals promote secondary pore development in dolomite, and exhibit the negative effect of occupying certain reservoir space. The results of this research can provide important guidance for oil and gas exploration in subsalt layers of saline lacustrine carbonate rocks.

Huang, K.Z., Tang, H.L., Xie, Y.F., 2018. Impacts of shale gas production wastewater on disinfection byproduct formation: An investigation from a non-bromide perspective. Water Research 144, 656-664.


The rapid rise of shale gas development has triggered environmental and human health concerns due to its impacts on water resources, especially on disinfection byproduct (DBP) formation upon chlorination. Despite the recently reported results on bromide, the effects of non-bromide ions in production wastewater at extremely high levels are vaguely defined. In this study, we investigated the effects of production wastewater, with bromide and non-bromide species, on the formation of DBPs when production wastewater was spiked into surface waters at various percentages. Results showed that the introduction of debrominated production wastewater led to increased formation of some chlorinated DBP species in selected surface water and wastewater. As the spiking percentage of debrominated production wastewater increased, the chlorinated DBP species increased. The contributions of individual cations to DBP formation followed a sequence of magnesium > calcium > barium at 0.10% spiking percentage due to the different catalytic effects of their chelates with organic precursors. The study of anions suggested that the discharge of treated production wastewater containing elevated sulfate may further enhance DBP formation. The significance of this study lies in the fact that in addition to bromide concerns from production

wastewater, non-bromide species also contributed to DBP formation. The gas production wastewater management decision should consider the negative impacts from both bromide and non-bromide species to better protect the receiving water resources.

Huang, K.Z., Xie, Y.F., Tang, H.L., 2019. Formation of disinfection by-products under influence of shale gas produced water. Science of The Total Environment 647, 744-751.


Accidental spills and surface discharges of shale gas produced water could contaminate water resources and generate health concerns. The study explored the formation and speciation of disinfection by-products (DBPs) during chlorination of natural waters under the influence of shale gas produced water. Results showed the presence of produced water as low as 0.005% changed the DBP profile measurably. A shift to a more bromine substitution direction for the formation of trihalomethanes, dihaloacetic acids, trihaloacetic acids, and dihaloacetonitriles was illustrated by exploring the individual DBP species levels, bromine substitution factors, and DBP species fractions, and the effect was attributable to the introduction of bromide from produced water. The ratio of dichloroacetic and trichloroacetic acids also increased, which was likely affected by different bromination degrees at elevated bromide concentrations. Increasing blend ratios of produced water enhanced the formation of DBPs, especially the brominated species, while such negative effects could be alleviated by pre-treating the produced water with ozone/air stripping to remove bromide. The study advances understandings about the impacts of produced water spills or surface discharges regarding potential violation of Stage 2 DBP rules at drinking water treatment facilities.


https://doi.org/10.1007/s12517-018-3762-5

Injection of CO2 into shale reservoir is regarded as one potential scenario for CO2 sequestration and enhanced gas recovery (CS-EGR). In this work, a realistic molecular model of kerogen in Chinese Silurian marine black shale was generated using molecular dynamics (MD) simulations. The competitive adsorption of CH4 and CO2 was simulated by the grand canonical Monte Carlo (GCMC) method under different reservoir pressures, temperatures, geological depths, CO2 mole ratios, and moisture contents of kerogen model. Results show that CO2/CH4 adsorption selectivity decreases with increasing reservoir pressure, indicating that CS-EGR can be more efficient if CO2 injection is conducted at the late development stage. The temperature has a negative effect on the selectivity, which indicates that thermal stimulation has an adverse effect on the efficiency of CS-EGR. Also, the selectivity decreases with increasing geological depth, suggesting that shallow shale formations are more suitable for CS-EGR. At low pressures, the selectivity increases with increasing CO2 mole ratio, while at high pressures, the selectivity decreases with the increase of CO2 mole ratio. This result suggests that CO2 mole ratio should be dynamically adjusted with the production so as to adapt to the changing reservoir pressure. At higher pressure condition, both the amounts of CO2 sequestration and CH4 desorption increase with the increase of CO2 mole fraction. However, the adsorption stability of CO2 weakens with increasing injection amounts of CO2. Moreover, the adsorption selectivity decreases initially, and then increases with the moisture content of kerogen. Thus, the performance of CS-EGR may be improved by increasing the kerogen moisture content for Silurian shale gas reservoirs. This study gains enhanced insights on the effect of reservoir pressure, temperature,

geological depth, CO2 mole ratio, and kerogen moisture content on CO2/CH4 competitive adsorption, and the results can provide applicable guidances for CS-EGR in shale gas reservoirs.

Huang, Y., Tarantola, A., Wang, W., Caumon, M.-C., Pironon, J., Lu, W., Yan, D., Zhuang, X., 2018. Charge history of CO2 in Lishui sag, East China Sea basin: Evidence from quantitative Raman analysis of CO2-bearing fluid inclusions. Marine and Petroleum Geology 98, 50-65.


The accumulation of carbon dioxide in natural gas reservoirs is common, and CO2 gas fields have been widely discovered in the world. In the last decades, three CO2 pools were discovered in Lishui sag, East China Sea Basin. Geochemical proxies indicate that CO2 in these gas reservoirs is dominated by mantle-source volcano degassing. Although three volcanic events occurred in the formation of these reservoirs, the CO2 charging period is not clear. In this study, pure CO2 , CO2-rich and H2O-rich fluid inclusions were found in healed micro-fractures and overgrowth zones of quartz in the reservoir of Lishui sag. The composition and density of two H2O-rich inclusions, two CO2-rich inclusions and twenty-three pure CO2 inclusions were determined by Raman quantitative analysis. The burial depth of CO2 fluid inclusion assemblages (FIA) can be determined by the trapping pressure constrained from Raman quantitative analysis and thermodynamic models. The combination of C-He isotope analyses, PT entrapment conditions of CO2-bearing inclusions, feature of fault activity and simulation of burial history permits to assign periods of CO2 fluid activity. The low-density (∼0.15 g cm−3) CO2 gas inclusions recorded an early-period of CO2 activity eruption to be related with the Late-Paleocene volcanic event. The mid-density (∼0.45 g cm−3) and high-density (∼0.75 g cm−3) CO2 inclusions were assigned to the Miocene volcanic event and to a later CO2 charging event during Pliocene.

Hubert, H.L., Rankey, E.C., Omelon, C., 2018. Organic matter, textures, and pore attributes of hypersaline lacustrine microbial deposits (Holocene, Bahamas). Journal of Sedimentary Research 88, 827-849.

https://doi.org/10.2110/jsr.2018.42

Discovery of lacustrine microbialite reservoirs in South Atlantic pre-salt has motivated the search for analogs for perspectives on their deposition and initial porosity. Although previous efforts mapped spatial patterns and produced facies models of large microbial lacustrine systems, details of the origins of microbialite fabrics are less well constrained. To address these unknowns, this study evaluates the influence of organic-matter source, abundance, and growth habit on Holocene microbialite fabrics. Integrated multi-scale analyses characterize fabrics of Holocene microbialites in a small (< 1 km2), shallow (< 1 m), hypersaline, alkaline lake on Crooked–Acklins Platform in the southern Bahamas. The results of analyses indicate systematic distribution of surface sediment across the lake, from various types of unlithified microbial mats to calcareous microbialites; bottom type relates to water depth. Spherules with laminae of radial aragonite are common in organic-rich mats, and can have competitive growth boundaries. Calcareous microbialites in the lake center can reach up to 60 cm tall and 2+ m across, and include macrofabrics and microfabrics that vary considerably, across micrometer to meter scales. Porosity varies from 43 to 59%, in pore types ranging from intra-fibrous (IF), breccia (BR), vuggy (VUG), intra- (WL) and inter-laminar (IL), digitate (DG), to branching (BRA). Microfabrics are not unique to individual macrofabrics, and organic-matter source is similar among fabrics. The abundance of organic matter and growth habit of organics on the outer parts of microbialites varies markedly among fabrics, suggesting that these parameters may control rock fabric. The occurrence of Mg silicates in association with these microbialites may favor

preservation of the depositional pores. Although ultimate preservation is unknown, understanding the genesis of primary fabrics may provide insights into possible pore evolution in reservoir analogs.

Hussien, O.S., Elraies, K.A., Almansour, A., Husin, H., Mohd Shuhili, J.A.B., 2018. Beyond fracking: Enhancement of shale gas desorption via surface tension reduction and wettability alteration. Journal of Natural Gas Science and Engineering 57, 322-330.


A significant amount of water used during hydraulic fracturing operation in shale reservoirs remains trapped in the formation mainly due to capillary forces. In this paper, the effect of Alpha Foamer® surfactant in enhancing the efficiency of the fracturing fluid was investigated in the presence and absence of Betain C60 as a co-surfactant at various fracturing water salinities. The performance of Alpha Foamer® surfactant was examined by measuring the surface tension and contact angle between the surfactant solutions and methane gas at different pressures and temperatures. The result indicates that Alpha Foamer® has significantly reduced the surface tension between water and methane gas from 69 mN/m to 33.2 mN/m at critical micelle concentration of 0.25 wt%. The addition of Betain C60 as a co-surfactant has slightly reduced the surface tension to 26.6 mN/m. It has also been observed that the increase in the pressure and temperature would be an advantage with additional reduction in the surface tension. In addition, the selected surfactant and co-surfactant concentrations have shown a significant reduction in the contact angle that makes the shale formation strongly water wet. The shifting of the wetting phase due to receding contact angle would aid in desorption of methane gas from shale matrix. The desorption is further enhanced with the reduction of surface tension between fracking fluid and methane gas by surfactant. The findings from this research can be used to optimize fracturing fluid, and to improve the overall sweep efficiency and shale gas productivity as well as water flowback.

Iglauer, S., 2018. Optimum storage depths for structural CO2 trapping. International Journal of Greenhouse Gas Control 77, 82-87.


Structural trapping is the primary CO2 geo-storage mechanism, and it has historically been quantified by CO2 column heights, which can be permanently immobilized beneath a caprock, using a buoyancy force-capillary force balance. However, the high dependence of CO2-wettability (a key parameter in the above analysis) on pressure and temperature – and thus storage depth – has not been taken into account. Importantly, rock can be CO2-wet at high pressure, and this wettability reversal results in zero structural trapping below a certain storage depth (∼2400 m maximum caprock depth for a most likely scenario is estimated here). Furthermore, more relevant than the CO2 column height is the actual mass of CO2 which can be stored by structural trapping (mCO2). This aspect has now been quantified here, and importantly, mCO2 goes through a maximum at ∼1300 m depth, thus there exists an optimal storage depth at around 1300 m depth.

Iqbal, O., Ahmad, M., Kadir, A.a., 2018. Effective evaluation of shale gas reservoirs by means of an integrated approach to petrophysics and geomechanics for the optimization of hydraulic fracturing: A case study of the Permian Roseneath and Murteree Shale Gas reservoirs, Cooper Basin, Australia. Journal of Natural Gas Science and Engineering 58, 34-58.


Brittleness and in-situ stress states are known critical indicators for screening prospected layers during hydraulic fracturing in unconventional reservoirs. Brittleness can be inferred from mechanical parameters and mineralogical data, primarily using empirical relations, although an incomplete dataset limits their use. Therefore, a dataset with a systematic framework was designed based on well logs, and details core data spudded in the Permian Roseneath and Murteree shales from the Cooper Basin, Australia. Petrophysical and geomechanical models were designed to indicate shale mineralogy, total organic richness, porosity, in-situ stress conditions, brittleness index, pore pressure, and fracture pressure gradient. After a review of various definitions of brittleness index (BI) in recent literature, it will be argued that the definition of a brittleness index is with reference to either elastic parameters, mineralogical composition, or strength parameters. Consequently, a higher brittleness index is assigned to quartz and siderite rich rocks than to clay, organic matter, and porosity rich rocks. Some recent definitions of BI are therefore useful for indicating rock types, but brittle/ductile behavior is not necessarily any indicator of brittle/ductile failure during stimulation. It is therefore proposed that an accurate BI must be incorporated into a geomechanical model. This new model will comprise the following properties: elastic and strength parameters, in-situ stress state, fracture pressure gradient, and pore pressure. Such an integrated model can be used to find 1) Fracture barriers (the layers hindering fracture growth); 2) Potential layers that enhance fracture growth, and; 3) Direction of induced fractures on the bases of the stress regime.

Jaeschke, A., Rethemeyer, J., Lappé, M., Schouten, S., Boeckx, P., Schefuß, E., 2018. Influence of land use on distribution of soil n-alkane δD and brGDGTs along an altitudinal transect in Ethiopia: Implications for (paleo)environmental studies. Organic Geochemistry 124, 77-87.


The combined use of plant wax n-alkane δD values and branched glycerol dialkyl glycerol tetraether lipid (brGDGT) distributions provides a novel approach for paleoaltitude reconstruction. Studies from East Africa revealed, however, inconsistent results between the proxy estimates and altitudinal parameters. Here, we explore these proxies in soils of different land use (forest, cropland and pasture) along an altitudinal transect in the Jimma zone of the southwest Ethiopian highlands to better understand environmental and plant-specific factors controlling the isotopic composition and distribution of n-alkanes and brGDGTs. The hydrogen isotope composition of individual n-alkanes does not unambiguously reflect the altitude effect on precipitation δD, but seems largely influenced by the specific land use. Only forest soil-derived n-C27 and n-C29 alkane δD values exhibit a significant linear relationship with altitude (r −0.87, p < 0.05), likely reflecting the most stable ecosystem. The resulting lapse rate of −17‰/1000 m is comparable with that of local precipitation in the southwest Ethiopian highlands. In addition, the linear correlation of the average chain length (ACL) and δ13C values of forest soil n-alkanes suggests a physiological adaptation of the specific plant type waxes to altitude-induced environmental changes in the study area. The distribution of brGDGTs also reveals a significant linear correlation with altitude (r −0.97, p < 0.01), reflecting the decrease in temperature with higher elevation, independent of land use. In addition, brGDGT-based mean annual air temperature (MAT) estimates of 19.5–14.0 °C and temperature lapse rate of −6 °C/1000 m are in good agreement with direct measurements in the Jimma zone. In contrast to previous studies from East Africa, our results show that both soil n-alkane δD values and brGDGT-based MAT distributions track present day altitude effects on local environmental gradients in the southwest Ethiopian highlands.

Jaroszewicz, E., Bojanowski, M., Marynowski, L., Łoziński, M., Wysocka, A., 2018. Paleoenvironmental conditions, source and maturation of Neogene organic matter from the siliciclastic deposits of the Orava-Nowy Targ Basin. International Journal of Coal Geology 196, 288-301.


The Orava-Nowy Targ Basin (ONTB) is an intramontane depression filled with Neogene and Quaternary deposits located at the junction of the Inner and Outer Carpathians. The Neogene infill of the basin consists mainly of siliciclastic rocks with very common lignite intercalations and is mostly of fluvial or lake origin.

The organic matter molecular analysis of seventeen Neogene samples confirmed the terrigenous origin of organic matter with a predominance of higher plant input in most samples, based on the distribution of n-alkanes and steranes, as well as the presence of tri- and tetracyclic diterpenoids, and triterpenoids representing oleanane, ursane, lupane, chrysene and picene derivatives. High concentrations of compounds originating from both angiosperms and gymnosperms suggest the presence of mixed forests. Additionally, important input of mosses into the primary organic matter is indicated by the high concentration of n-C23 and presence of hop-17(21)-enes in most samples. A high Average Aromatic Ring and Conifer Wood Degradation Index >0.7 indicate high activity of bacteria and wood-degrading fungi in the sedimentary environment. There was no evidence of weathering and scarce signs of biodegradation were identified. All samples were subjected to water washing.

Huminite reflectance and biomarker-based parameters, as well as the presence of unsaturated pentacyclic triterpenoids and steroids indicate an immature organic matter. A trend of decreasing maturation of sediments from east to the west was observed, as was a similarity of thermal maturity between the Podhale Synclinorium and the ONTB, although the latter seems to be coincidental. A thermal gradient value of 35 °C/km was assumed for calculating the maximum thickness of eroded strata, resulting in 1–1.6 km for the SE area and a maximum temperature of the deepest buried samples equal to 45–65 °C.

Jennerwein, M., Eschner, M., Wilharm, T., Gröger, T., Zimmermann, R., 2019. Evaluation of reversed phase versus normal phase column combination for the quantitative analysis of common commercial available middle distillates using GC × GC-TOFMS and Visual Basic Script. Fuel 235, 336-338.


Normal and reversed phase column combinations for comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry were evaluated concerning their suitability for the analysis of common commercial available middle distillates. Compound classes were identified and quantified by applying a previously developed data evaluation method (Jennerwein et al., 2014) [1] for middle distillates based on GC × GC-TOFMS using “normal phase” column combination and Visual Basic Scripting (VBS). The GC × GC-TOFMS methodology was transferred to a “reversed phase” column combination and it could be found, that this kind of column combination provides advantages for the quantification of petrochemical samples in terms of precision of the results. Special improvements were observed for the quantification of aromatics and paraffins.



Saline and freshwater lacustrine oils from the Dongpu Depression (Bohai Bay Basin) were characterized by negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance

mass spectrometry (FT-ICR MS). ESI-FT-ICR MS detected a large range of nitrogen and oxygen compounds in the oils, mostly comprising N1, O1, O2 and N1O1 species. The low mature oils are dominated by O1 species with double bond equivalent of 4 (DBE = 4; mainly alkylphenols), O2 species with DBE = 5–6 (i.e., hopanoid, secohopanoic and steroid acids) and DBE = 1 (i.e., fatty acids), indicating a genetic relationship between oxygen compounds and their precursors. The nitrogen and oxygen compounds were significantly influenced by maturity, with the lower maturity oils analyzed enriched in O2 species, particularly fatty acids and 4–5 ring naphthenes with biologically sourced hydrocarbon skeletons: ratios of O2/N1 > 0.7; C20–30/C15–45-DBE1-O2 >0.4; and DBE5–6/DBE12–22-O2 >3.0 may be useful indicators of low maturity. With increasing maturity, the condensation degree of the compounds increased and the carbon number decreased. The relative abundances of N1 and O1 species with the following specific DBE carbon number ranges were particularly sensitive to maturity: DBE9–12/DBE15–18-N1, C20–28/C29–40-DBE12-N1, C20–30/C31–50-DBE15-N1, DBE9–12/DBE4–20-O1 and C20–30/C31–50-DBE8-O1. In some instances the FT-ICR MS proxies provided a more reliable indication of high maturity levels than traditional sterane based maturity parameters. However, several of these species were also responsive to other influences, namely C20–28/C29–40-DBE12-N1 and C20–30/C31–50-DBE15-N1 ratios reflected an organofacies control and DBE9–12/DBE4–20-O1 and C20–30/C31–50-DBE8-O1 ratios changed with thermochemical sulfate reduction (TSR)– confirmed by δ34S variances of OSCs. In light of the multiple controls on the nitrogen and oxygen compounds, DBE9–12/DBE15–18-N1 ratio seems unaffected by organofacies or TSR and was considered the most reliable maturity proxy displaying a similar or better maturity relationship than Ts/(Ts + Tm). Aside from secondary alteration effects, the freshwater samples showed several compositional differences to the saline samples, albeit from a limited data set, including generally higher O2 and N1 (particularly low MW) product abundances, lower abundances and quite different distribution of O1 products. These distinctions suggest ESI-FT-ICRMS analysis has potential for distinguishing these sample types.

Ji, S., Nie, J., Lechler, A., Huntington, K.W., Heitmann, E.O., Breecker, D.O., 2018. A symmetrical CO2 peak and asymmetrical climate change during the middle Miocene. Earth and Planetary Science Letters 499, 134-144.


Understanding the future trajectory of Earth's climate requires knowledge of shifts in atmospheric CO2 concentrations during past warm episodes. The Miocene Climatic Optimum (MCO, ∼17–14 Ma) was likely the warmest episode of the past 25 Myr, and thus atmospheric CO2 concentrations during this interval are of particular interest. However, CO2 records across the middle Miocene are rather scattered and data are notably sparse for the latter part of the MCO. Here we present a paleosol-based CO2 record from the Tianshui Basin, northern China, spanning 17–7 Ma. Our results show elevated mean CO2 during the second half of the MCO corresponding with some of the lowest benthic δ18O values and highest benthic δ13C values, as part of the “Monterey excursion”, published for the Neogene. This result supports the idea that the broader Monterey excursion was primarily associated with a CO2 maximum, not carbon burial and CO2 minima as previously interpreted. The new CO2 record, along with previous CO2 records based on paleosols, stomata and foraminiferal boron isotope compositions, also suggests that mean CO2 across the MCO was elevated compared with the immediately following (post-MCO, 14–11 Ma, >80% probability) and immediately preceding (pre-MCO, 20–17 Ma, 70% probability) time periods. The most probable magnitude of the MCO CO2 peak is 20% higher than post-MCO and 12.5% higher than pre-MCO levels. Larger factors, of perhaps 50% higher CO2, likely apply in narrower (<1 Myr) time slices. CO2 records from each proxy individually support the conclusion of modestly elevated MCO CO2, although large temporal gaps exist in records from any one proxy. Using all proxies together, we estimate average MCO CO2 of

375+150/−100 (84th and 16th percentile) ppm. Although mean MCO CO2 was elevated, the MCO was also characterized by highly variable CO2. In addition, determinations from all three proxies suggest that at times during the MCO, CO2 levels were as low as they were following the ice sheet expansion of the Miocene Climate Transition. Furthermore, pre-MCO CO2 levels are indistinguishable from post-MCO CO2 levels (60% probability of pre-MCO CO2 > post-MCO CO2), despite significantly lower benthic δ18O values during the former. We conclude that 1) the MCO was a period of slightly elevated and highly variable CO2 compared with the immediately preceding and following intervals, and 2) neither CO2 decrease, orbitally-controlled seasonality over Antarctica nor the confluence of these factors was sufficient to cause Miocene Climate Transition ice sheet expansion. Rather strengthening of the Antarctic Circumpolar Current and Southern Ocean cooling related to closure of the eastern Tethys was a necessary first step.

Jia, X., Dini-Andreote, F., Falcão Salles, J., 2018. Community assembly processes of the microbial rare biosphere. Trends in Microbiology 26, 738-747.


Our planet teems with microorganisms that often present a skewed abundance distribution in a local community, with relatively few dominant species coexisting alongside a high number of rare species. Recent studies have demonstrated that these rare taxa serve as limitless reservoirs of genetic diversity, and perform disproportionate types of functions despite their low abundances. However, relatively little is known about the mechanisms controlling rarity and the processes promoting the development of the rare biosphere. Here, we propose the use of multivariate cut-offs to estimate rare species and phylogenetic null models applied to predefined rare taxa to disentangle the relative influences of ecoevolutionary processes mediating the assembly of the rare biosphere. Importantly, the identification of the factors controlling rare species assemblages is critical for understanding the types of rarity, how the rare biosphere is established, and how rare microorganisms fluctuate over spatiotemporal scales, thus enabling prospective predictions of ecosystem responses.

Jiang, W., Pacella, M.S., Vali, H., Gray, J.J., McKee, M.D., 2018. Chiral switching in biomineral suprastructures induced by homochiral L-amino acid. Science Advances 4, Article eaas9819.

http://advances.sciencemag.org/content/4/8/eaas9819.abstract

How homochiral L-biomolecules in nature induce a chiral switch in biomineralized architectures is unknown, although chiral switching is common in many calcium carbonate–hardened structures found in marine and terrestrial organisms. We created hierarchically organized, chiral biomineral structures of calcium carbonate, whose chirality can be switched by a single L-enantiomer of an amino acid. The control of this chiral switching involves two stages: a calcium carbonate (vaterite) platelet layer inclination stage, followed by a platelet layer rotation stage, the latter stage being responsible for successional chiral switching events within the biomineralized structures. The morphology of the synthesized chiral vaterite structures remarkably resembles pathologic chiral vaterite otoconia found in the human inner ear. In general, these findings describe how a single-enantiomer amino acid might contribute to biomineral architectures having more than one chirality as is commonly seen in biology, and more specifically, they suggest how pathologic chiral malformations may arise in humans.

Jiang, Z., Zhang, S., Klausen, L.H., Song, J., Li, Q., Wang, Z., Stokke, B.T., Huang, Y., Besenbacher, F., Nielsen, L.P., Dong, M., 2018. In vitro single-cell dissection revealing the interior structure of cable bacteria. Proceedings of the National Academy of Sciences 115, 8517-8522.


Significance: Cable bacteria were recently discovered as the facilitators of electron transfer over centimeter distances in marine sediments. In this work, we explore the unique structure of the cable bacteria, using atomic force microscopy-based single-cell in vitro dissection. We identify different types of bacterial cell–cell junctions and continuous dimeric strings hidden under the outer membrane that pass through the cell junctions. The strings seem to serve an important function in maintaining the integrity of individual cable bacteria cells as a united filament. On the basis of our findings, we propose a model for the division and growth of the cable bacteria, which illustrate the possible structural requirements for the formation of centimeter-length filaments in the recently discovered cable bacteria.

Abstract: Filamentous Desulfobulbaceae bacteria were recently discovered as long-range transporters of electrons from sulfide to oxygen in marine sediments. The long-range electron transfer through these cable bacteria has created considerable interests, but it has also raised many questions, such as what structural basis will be required to enable micrometer-sized cells to build into centimeter-long continuous filaments? Here we dissected cable bacteria cells in vitro by atomic force microscopy and further explored the interior, which is normally hidden behind the outer membrane. Using nanoscale topographical and mechanical maps, different types of bacterial cell–cell junctions and strings along the cable length were identified. More important, these strings were found to be continuous along the bacterial cells passing through the cell–cell junctions. This indicates that the strings serve an important function in maintaining integrity of individual cable bacteria cells as a united filament. Furthermore, ridges in the outer membrane are found to envelop the individual strings at cell–cell junctions, and they are proposed to strengthen the junctions. Finally, we propose a model for the division and growth of the cable bacteria, which illustrate the possible structural requirements for the formation of centimeter-length filaments in the recently discovered cable bacteria.



The coals in South China has not been well investigated because the coal mines are small in volume compared with the well-known large-scale coal accumulations in North China, thus the nature of such coals is of significance to study. The nanopore characteristics and surface roughness of 14 coal samples that have experienced low degrees of tectonic deformation as a naturally matured coal series in South China were addressed. Atomic force microscopy (AFM) and image processing were applied in a study of relationships between nanopore development, surface roughness, and thermal maturity (indicated by vitrinite reflectance; Ro = 0.65%–4.43%) in the naturally matured coal series. The results show that areal porosities of the coal samples are 0.78%–9.33%, with mean pore sizes of 7.9–27.9 nm. There were three main stages of pore evolution related to thermal maturity, with Ro values of <1.3%, 1.3%–3.7%, and >3.7%. Pore number, areal porosity, and mean pore size follow a cyclical downward/upward trend across the three stages. Arithmetical mean (Ra) and root-mean-square (Rq) surface roughness values are 1.69–17.74 nm and 2.24–28.81 nm, respectively. Ra and Rq values of coal samples with relatively low thermal maturity (Ro < 1.3%) are controlled mainly by coal maceral and mineral composition, whereas values for coals with relatively high thermal maturity (Ro > 1.3%)

are controlled by nanopore development. Thermal maturity is an important factor that influences the nanopore and surface roughness characteristics of naturally matured coals in South China.



Fire is one of the most important modulating factors of the environment and the forest inducing chemical and biological changes on the most reactive soil component, the soil organic matter (SOM). Assuming the complex composition of the SOM, we used an ultra-high resolution mass spectrometry analysis technique to assess the chemical composition and fire-induced alterations in soil particle size fractions (coarse and fine) from a sandy soil in a Mediterranean oak forest at Doñana National Park (Southwest Spain). Electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) showed that the coarse fraction of soils not affected by fires consisted mainly of polyphenolic compounds consistent with little-transformed SOM and fresh biomass, whereas the fine fraction was enriched in protein and lipid like homologues suggesting microbially reworked SOM. In fire-affected SOM, the coarse fraction contained a high proportion of aromatic compounds, consistent with inputs of charred litter or in situ chemical transformation of the SOM. Analysis of the fine fraction revealed two differentiated chemical families pointing to the existence of two carbon pools; a native microbial-derived moiety composed of lipids and polypeptide compounds, and a secondary, pyrogenic or thermally-altered moiety rich in aromatic compounds. This work represents the first application of ultra-high resolution mass spectrometry to study the chemical composition of SOM in different particle size fractions.

Jin, B., Nasrabadi, H., 2018. Phase behavior in shale organic/inorganic nanopores from molecular simulation. SPE Reservoir Evaluation & Engineering 21, 626-637.

https://doi.org/10.2118/187307-PA

Production from shale reservoirs is receiving more attention from the petroleum industry. However, there are many complexities associated with optimal production of shale reservoirs. One complexity is the unclear fluid-phase behavior in shale nanopores. In the shale nanopores, the interaction between the pore wall and fluid molecules can significantly change the fluid-phase behavior from the bulk (unconfined) condition. Therefore, the type of pore material can influence the fluid-phase behavior. There have been several recent efforts to model the confined fluid-phase behavior in shale reservoirs. However, the effect of pore material on fluid-phase behavior in shale reservoirs has not been addressed in the previous studies. In this paper, to have a better understanding of phase diagrams in different shale environments, we perform molecular simulations with three materials (two inorganic minerals and one kerogen) and two types of nanopores (slit and cylinder) to model the confined-phase behavior of pure fluids (methane and propane) and one ternary fluid (C1/C3/nC5). From the pure-fluid simulations in the pores of three diameters (4, 7, and 10 nm), confined liquid densities are decreased, whereas vapor densities are increased in the slit and cylinder pores. When pore diameters are increased, critical points are shifted to low densities and high temperatures. Critical temperature and density under confinement can deviate as high as 15 and 60%, respectively, from the original values in bulk. Molecular simulations are conducted for the ternary fluid in the slit and cylinder pores at 160°F. Under confinement, there is a large shift in the nC5 composition of the vapor phase in the ternary diagrams, whereas only small changes have been observed in the ternary diagrams of liquid

phase. The density difference between two phases is reduced. Additional tests are performed at one typical shale temperature (290°F) for this ternary fluid in both nanopore types. Phase separation is observed in the slitpore tests, although only one phase is formed in the tests of the cylinder pores. Because the cylinder pore has more adsorption surface area compared with the slit pore, a stronger adsorption effect is introduced in all tests of the cylinder pores. Based on the comparison of all results (pure fluids and ternary fluid) from the three materials, the calcite pores provide a stronger confinement effect on fluids, and the other two materials have a similar confinement effect on the phase diagrams.

Johann, L., Shapiro, S.A., Dinske, C., 2018. The surge of earthquakes in Central Oklahoma has features of reservoir-induced seismicity. Scientific Reports 8, Article 11505.

https://doi.org/10.1038/s41598-018-29883-9

The recent surge of seismicity in Oklahoma and Kansas is related to fluid disposal. Evidences suggest that critical parameters are the injection volume as well as injection depth but dominant physical processes and a corresponding model to describe the physics are still not clear. We analyse the spatio-temporal distribution of induced earthquakes in the basement and find visible signatures of pore pressure diffusion and poroelastic coupling, features which strongly resemble seismicity induced by the filling of artificial lakes, so-called reservoir-induced seismicity. We developed a first-principle model of underground reservoir-induced seismicity. The physics of the model are based upon the combined mechanisms of fluid mass added to the pore-space of the injection layer and acting as a normal stress on the basement surface, pore-fluid pressure diffusion in the basement as well as poroelastic coupling contributing to the pore-fluid pressure and stress. Furthermore, we demonstrate that underground reservoir-induced seismicity occurs preferably in normal faulting and strike-slip settings, the latter being prevalent in Oklahoma. Our model explains observed injection volume and depth dependence of the seismicity and should be considered as a basis for future hazard prediction and prevention as well as for planning possible disposal sites.

Kan, J., 2018. Storm events restructured bacterial community and their biogeochemical potentials. Journal of Geophysical Research: Biogeosciences 123, 2257-2269.

https://doi.org/10.1029/2017JG004289

Abstract Large rainstorms deliver significant amounts of upland materials to headwater streams, thereby introducing the particle-associated microorganisms from complex soil environments into stream networks. ?Seeding and mixing? from terrestrial sources may generate ?new? in-stream microbial consortia and facilitate nutrient transformations and export to receiving waters. In order to investigate how large storm events influence the microbial community, bacterial community structure from White Clay Creek (Chester Co., PA, USA) was characterized following the Hurricane Irene and the Tropical Storm Lee. High-throughput sequencing of the 16S rRNA genes was used to track changes of bacterial community before, during, and after the events. Detailed bacterial community structures based on analyses of 3,004,072 sequences indicated an increase of bacterial diversity during peak discharge of the storm. Significant successional changes of bacterial community structure during the events were observed: Betaproteobacteria decreased in relative abundance, while members of Deltaproteobacteria, Acidobacteria, Chloroflexi, Nitrospirae, Planctomycetes, and Verrucomicrobia increased with the discharge suggesting potential impacts from terrestrial inputs and re-suspended sediments. Cyanobacteria bloomed after the storm events, indicating that photosynthesis was one of the primary recovering processes. Real-time polymerase chain reaction (quantitative polymerase chain reaction) analyses on functional genes (amoA for nitrification and nirS/nirK for

denitrification) suggested that storm events also changed the functional perspectives of the microbial communities, with the potential for alteration of subsequent biogeochemical transformations. Thus, large storm events inoculate microbes from terrestrial and streambeds to headwaters, and downslope dispersal (?mass-effect?) and ?species-sorting? likely restructure the microbial community as well as potential nutrient cycling.

Käppler, A., Fischer, M., Scholz-Böttcher, B.M., Oberbeckmann, S., Labrenz, M., Fischer, D., Eichhorn, K.-J., Voit, B., 2018. Comparison of μ-ATR-FTIR spectroscopy and py-GCMS as identification tools for microplastic particles and fibers isolated from river sediments. Analytical and Bioanalytical Chemistry 410, 5313-5327.

https://doi.org/10.1007/s00216-018-1185-5

In recent years, many studies on the analysis of microplastics (MP) in environmental samples have been published. These studies are hardly comparable due to different sampling, sample preparation, as well as identification and quantification techniques. Here, MP identification is one of the crucial pitfalls. Visual identification approaches using morphological criteria alone often lead to significant errors, being especially true for MP fibers. Reliable, chemical structure-based identification methods are indispensable. In this context, the frequently used vibrational spectroscopic techniques but also thermoanalytical methods are established. However, no critical comparison of these fundamentally different approaches has ever been carried out with regard to analyzing MP in environmental samples. In this blind study, we investigated 27 single MP particles and fibers of unknown material isolated from river sediments. Successively micro-attenuated total reflection Fourier transform infrared spectroscopy (μ-ATR-FTIR) and pyrolysis gas chromatography-mass spectrometry (py-GCMS) in combination with thermochemolysis were applied. Both methods differentiated between plastic vs. non-plastic in the same way in 26 cases, with 19 particles and fibers (22 after re-evaluation) identified as the same polymer type. To illustrate the different approaches and emphasize the complementarity of their information content, we exemplarily provide a detailed comparison of four particles and three fibers and a critical discussion of advantages and disadvantages of both methods.

Karlapudi, A.P., Venkateswarulu, T.C., Tammineedi, J., Kanumuri, L., Ravuru, B.K., Dirisala, V.r., Kodali, V.P., 2018. Role of biosurfactants in bioremediation of oil pollution-a review. Petroleum 4, 241-249.


The energy resources mainly petroleum and petroleum hydrocarbons are major pollutants of the environment. The oil and oil products contamination may cause severe harm and hence, the attention has been remunerated in the development of alternative technologies for elimination of these contaminants. Biosurfactants were used in the remediation of oil pollution due to advantages such as biodegradability and low toxicity. The biosurfactants are produced from low cost substrates like agro-industrial wastes which reduce the cost of production. Biosurfactants and bioemulsifiers are amphiphilic compounds and are produced as extracellular or a part of the cell membrane by bacteria. The insight view, how hydrocarbons are degraded by microorganisms and thereby reduce the damage of ecosystem is highly essential to target the problem. Biofilms are the bacterial communities which protects the bacterial cells from various adverse conditions. The present review describes the biosurfactants and its synthesis from bacteria and also emphases on the role of surfactants in oil remediation.

Keating, J.E., Glish, G.L., 2018. Dual emitter nano-electrospray ionization coupled to differential ion mobility spectrometry-mass spectrometry for shotgun lipidomics. Analytical Chemistry 90, 9117-9124.


Current lipidomics workflows are centered around acquisition of large data sets followed by lengthy data processing. A dual nESI-DIMS-MS platform was developed to perform real-time relative quantification between samples, providing data required for biomarker discovery and validation more quickly than traditional ESI-MS approaches. Nanosprayer activity and DIMS compensation field settings were controlled by a LabVIEW program synced to the accumulation portion of the ion trap scan function, allowing for full integration of the platform with a commercial mass spectrometer. By comparing samples with short electrospray pulses rather than constant electrospray, the DIMS and MS performance is normalized within an experiment, as signals are compared between individual mass spectra (ms time scale) rather than individual experiments (min–hr time scale). The platform was validated with lipid standards and extracts from nitrogen-deprived microalgae. Dual nESI-DIMS requires minimal system modification and is compatible with all traditional ion activation techniques and mass analyzers, making it a versatile improvement to shotgun lipidomics workflows.


https://doi.org/10.1038/s41559-018-0624-1

Bone is the key innovation underpinning the evolution of the vertebrate skeleton, yet its origin is mired by debate over interpretation of the most primitive bone-like tissue, aspidin. This has variously been interpreted as cellular bone, acellular bone, dentine or an intermediate of dentine and bone. The crux of the controversy is the nature of unmineralized spaces pervading the aspidin matrix, which have alternatively been interpreted as having housed cells, cell processes or Sharpey’s fibres. Discriminating between these hypotheses has been hindered by the limits of traditional histological methods. Here, we use synchrotron X-ray tomographic microscopy to reveal the nature of aspidin. We show that the spaces exhibit a linear morphology incompatible with interpretations that they represent voids left by cells or cell processes. Instead, these spaces represent intrinsic collagen fibre bundles that form a scaffold about which mineral was deposited. Aspidin is thus acellular dermal bone. We reject hypotheses that it is a type of dentine, cellular bone or transitional tissue. Our study suggests that the full repertoire of skeletal tissue types was established before the divergence of the earliest known skeletonizing vertebrates, indicating that the corresponding cell types evolved rapidly following the divergence of cyclostomes and gnathostomes.

Keigwin, L.D., Klotsko, S., Zhao, N., Reilly, B., Giosan, L., Driscoll, N.W., 2018. Deglacial floods in the Beaufort Sea preceded Younger Dryas cooling. Nature Geoscience 11, 599-604.

https://doi.org/10.1038/s41561-018-0169-6

A period of cooling about 13,000 years ago interrupted about 2,000 years of deglacial warming. Known as the Younger Dryas (YD), the event is thought to have resulted from a slowdown of the Atlantic meridional overturning circulation in response to a sudden flood of Laurentide Ice Sheet meltwater that reached the Nordic Seas. Oxygen isotope evidence for a local source of meltwater to the open western North Atlantic from the Gulf of St Lawrence has been lacking. Here we report that the eastern Beaufort Sea contains the long-sought signal of 18O-depleted water. Beginning at ~12.94

± 0.15 thousand years ago, oxygen isotopes in the planktonic foraminifera from two sediment cores as well as sediment and seismic data indicate a flood of meltwater, ice and sediment to the Arctic via the Mackenzie River that lasted about 700 years. The minimum in the oxygen isotope ratios lasted ~130 years. We suggest that the floodwater travelled north along the Canadian Archipelago and then through the Fram Strait to the Nordic Seas, where freshening and freezing near sites of deep-water formation would have suppressed convection and caused the YD cooling by reducing the meridional overturning.

Kenkel, S., Mittal, A., Mittal, S., Bhargava, R., 2018. Probe–sample interaction-independent atomic force microscopy–infrared spectroscopy: Toward robust nanoscale compositional mapping. Analytical Chemistry 90, 8845-8855.


Nanoscale topological imaging using atomic force microscopy (AFM) combined with infrared (IR) spectroscopy (AFM-IR) is a rapidly emerging modality to record correlated structural and chemical images. Although the expectation is that the spectral data faithfully represents the underlying chemical composition, the sample mechanical properties affect the recorded data (known as the probe–sample-interaction effect). Although experts in the field are aware of this effect, the contribution is not fully understood. Further, when the sample properties are not well-known or when AFM-IR experiments are conducted by nonexperts, there is a chance that these nonmolecular properties may affect analytical measurements in an uncertain manner. Techniques such as resonance-enhanced imaging and normalization of the IR signal using ratios might improve fidelity of recorded data, but they are not universally effective. Here, we provide a fully analytical model that relates cantilever response to the local sample expansion which opens several avenues. We demonstrate a new method for removing probe–sample-interaction effects in AFM-IR images by measuring the cantilever responsivity using a mechanically induced, out-of-plane sample vibration. This method is then applied to model polymers and mammary epithelial cells to show improvements in sensitivity, accuracy, and repeatability for measuring soft matter when compared to the current state of the art (resonance-enhanced operation). Understanding of the sample-dependent cantilever responsivity is an essential addition to AFM-IR imaging if the identification of chemical features at nanoscale resolutions is to be realized for arbitrary samples.

Kent, A.G., Garcia, C.A., Martiny, A.C., 2018. Increased biofilm formation due to high-temperature adaptation in marine Roseobacter. Nature Microbiology 3, 989-995.

https://doi.org/10.1038/s41564-018-0213-8

Ocean temperatures will increase significantly over the next 100 years due to global climate change. As temperatures increase beyond current ranges, it is unclear how adaptation will impact the distribution and ecological role of marine microorganisms. To address this major unknown, we imposed a stressful high-temperature regime for 500 generations on a strain from the abundant marine Roseobacter clade. High-temperature-adapted isolates significantly improved their fitness but also increased biofilm formation at the air–liquid interface. Furthermore, this altered lifestyle was coupled with genomic changes linked to biofilm formation in individual isolates, and was also dominant in evolved populations. We hypothesize that the increasing biofilm formation was driven by lower oxygen availability at elevated temperature, and we observe a relative fitness increase at lower oxygen. The response is uniquely different from that of Escherichia coli adapted to high temperature3 (only 3% of mutated genes were shared in both studies). Thus, future increased temperatures could

have a direct effect on organismal physiology and an indirect effect via a decrease in ocean oxygen solubility, leading to an alteration in microbial lifestyle.

Keshet, U., Goldshlag, P., Amirav, A., 2018. Pesticide analysis by pulsed flow modulation GCxGC-MS with Cold EI—an alternative to GC-MS-MS. Analytical and Bioanalytical Chemistry 410, 5507-5519.

https://doi.org/10.1007/s00216-017-0757-0

We explored the use of pulsed flow modulation (PFM) two-dimensional comprehensive gas chromatography (GC×GC) mass spectrometry with supersonic molecular beams (SMB) (also named Cold electron ionization (EI)) for achieving universal pesticide analysis in agricultural products. The use of GC×GC serves as an alternative to MS-MS in the needed reduction of matrix interference while enabling full-scan MS operation for universal pesticide analysis with reduced number of false negatives. Matrix interference is further reduced with Cold EI in view of the enhancement of the molecular ions. Pulsed flow modulation is a simple GC×GC modulator that does not consume cryogenic gases while providing tuneable second GC×GC column injection time for enabling the use of quadrupole-based mass spectrometry regardless its limited scanning speed. PFM-GC×GC-MS with Cold EI combines improved separation of GC×GC with Cold EI benefits of tailing-free ultra-fast ion source response time and enhanced molecular ions for the provision of increased sample identification information and reduced matrix interference. Consequently, PFM GC×GC-MS with Cold EI also improved NIST library identification probabilities of the spiked pesticides. PFM GC×GC is further characterized by largely increased second column sample and matrix capacity that as a result performs much better than thermal modulation GC×GC-MS with standard EI in the suppression of matrix interference. In a comparison with standard GC-MS, we measured with PFM GC×GC-MS with Cold EI an average total ion count matrix interference reduction factor of 32 for 12 pesticides in two matrices of baby leaves mixture and lettuce. In addition, Cold EI further increases the range of pesticides amenable for GC-MS analysis and its response is relatively uniform hence with it the need for pesticides specific calibration is reduced.

Khatami, M.S., Shahsavand, A., 2018. Application of population balance theory for dynamic modeling of methane and ethane hydrate formation processes. Energy & Fuels 32, 8131-8144.


Natural gas hydrates are considered as a promising fuel source in the relatively near future. Kinetic modeling of various steps of the natural gas hydrate formation process, such as dissolution, nucleation, and growth processes, has received numerous attentions. A novel mechanism is introduced for the entire nucleation and growth steps, and a proper mathematical model is presented to estimate the gas consumption rate in a constant temperature and pressure process. The proposed model covers the entire dissolution, nucleation, and growth stages. The combined Lax–Wendroff/Crank–Nicolson method is employed to solve the population balance equation for estimation of total surface area of evolved hydrate particles and corresponding particle size distributions. A special class of artificial neural network (known as the Regularization Network) is used to predict the solid–liquid equilibria. The proposed model is successfully validated using experimental data borrowed from the literature for both methane and ethane hydrate formation processes. The simulation results indicate that, for both methane and ethane species, the mole fractions in the bulk of liquid are often close to the corresponding concentrations at solid–liquid interfaces and decrease over the time during hydrate growth processes. It is clearly demonstrated that

the overall resistance shifts from the nucleation reaction to mass transfer as the hydrate formation progresses.

Khatibi, S., Ostadhassan, M., Xie, Z.H., Gentzis, T., Bubach, B., Gan, Z., Carvajal-Ortiz, H., 2019. NMR relaxometry a new approach to detect geochemical properties of organic matter in tight shales. Fuel 235, 167-177.


Understanding organic matter properties in terms of maturity and production potential are crucial for the initial assessment of unconventional plays. This is important since the amount of hydrocarbon that can be generated is a function of organic matter type and content in the formation and its thermal maturity. The complexity of shale plays in terms of constituent components has demonstrated that new analytical methods should be acquired to better understand hydrocarbon generation processes. In this study, a few samples from the upper and lower members of the Bakken Formation in the USA were selected from different depths and maturity levels. The samples were analyzed by a high frequency (22 MHz) nuclear magnetic resonance (NMR relaxometry) equipment, followed by Rock-Eval pyrolysis (using the Basic/Bulk-Rock method for all samples and a multi-heating rate method, MHR, for the two least mature samples) and bitumen reflectance evaluations. Results showed NMR can detect different hydrogen populations within the samples and distinguish among phases, such as solid organic matter, hydrocarbons (mobile oil), and water by T1-T2 mapping. We were also able to relate different identified areas on NMR T1-T2 maps to geochemical parameters of the organic matter obtained from Rock-Eval pyrolysis (such as S1, S2, and HI) and with thermal maturity (vitrinite reflectance-equivalent).

Kim, J.-Y., Kim, D.-U., Kang, M.-S., Jang, J.H., Kim, S.J., Kim, M.J., Lee, J.Y., Lee, Y.S., Zhang, J., Lim, S., Kim, M.K., 2018. Roseomonas radiodurans sp. nov., a gamma-radiation-resistant bacterium isolated from gamma ray-irradiated soil. International Journal of Systematic and Evolutionary Microbiology 68, 2443-2447.

http://ijs.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.002852

A bacterial strain, designated 17Sr1-1T, was isolated from gamma ray-irradiated soil. Cells of this strain were Gram-stain-negative, strictly aerobic, motile and non-spore-forming rods. Growth occurred at 18–42 ˚C and pH 6.0–8.0, but no growth occurred at 2 % NaCl concentration. The major fatty acids of strain 17Sr1-1T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), iso-C17 : 1 ω5c and C16 : 0. The polar lipid profile contained diphosphatidylglycerol, glycolipid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and four unidentified lipids. The G+C content of the genomic DNA of 17Sr1-1T was 71.9 mol%. The 16S rRNA gene sequence analysis showed that strain 17Sr1-1T was phylogenetically related to Roseomonas pecuniae N75T and Roseomonas rosea 173-96T

(96.6 and 96.3 % sequence similarity, respectively). The genotypic and phenotypic data showed that strain 17Sr1-1T could be distinguished from its phylogenetically related species, and that this strain represented a novel species within the genus Roseomonas , for which the name Roseomonas radiodurans sp. nov. (type strain 17Sr1-1T=KCTC 52899T=NBRC 112872T) is proposed as the first reported gamma ray-resistant Roseomonas species. The GenBank accession number for the 16S rRNA gene sequence of strain 17Sr1-1T is KY887689.

Kipp, M.A., Stüeken, E.E., Yun, M., Bekker, A., Buick, R., 2018. Pervasive aerobic nitrogen cycling in the surface ocean across the Paleoproterozoic Era. Earth and Planetary Science Letters 500, 117-126.


Nitrogen isotope ratios in marine sedimentary rocks have become a widely used biogeochemical proxy that records information about nutrient cycling and redox conditions in Earth's distant past. While the past two decades have seen considerable progress in our understanding of the Precambrian sedimentary nitrogen isotope record, it is still compromised by substantial temporal gaps. Furthermore, quantitative links between nitrogen isotope data, marine redox conditions, and nutrient availability are largely lacking in a Precambrian context. Here we present new nitrogen isotope data from a suite of marine sedimentary rocks with ca. 2.4 to 1.8 Ga ages, spanning the Great Oxidation Event in the Paleoproterozoic, to better constrain the response of the nitrogen cycle to the first major redox transition in Earth's history. We further construct a simple box model to describe the major pathways that influenced the nitrogen isotope mass balance of the Precambrian ocean and use this as a platform to evaluate the Precambrian nitrogen isotope record. Within this framework, we find that consistently positive nitrogen isotope values, ranging from +1.1 to +7.7‰, across the early Paleoproterozoic are strong evidence for an expansion of oxygenated surface waters. Since the isotopic signature of aerobic nitrogen cycling is recorded in the biomass of nitrate-assimilating organisms, this implicates widespread nitrate bioavailability in this time interval. The decline in offshore nitrogen isotope ratios in the Mesoproterozoic is consistent with the contraction of oxic waters, which could have inhibited the expansion of nitrate-fueled ecosystems to pelagic waters until the widespread oxygenation of the ocean in the latest Neoproterozoic to early Phanerozoic.

Kiuru, P., Ojala, A., Mammarella, I., Heiskanen, J., Kämäräinen, M., Vesala, T., Huttula, T., 2018. Effects of climate change on CO2 concentration and efflux in a humic boreal lake: A modeling study. Journal of Geophysical Research: Biogeosciences 123, 2212-2233.

https://doi.org/10.1029/2018JG004585

Climate change may have notable impacts on carbon cycling in freshwater ecosystems, especially in the boreal zone. Higher atmospheric temperature and changes in annual discharge patterns and carbon loading from the catchment affect the thermal and biogeochemical conditions in a lake. We developed an extension of a one‐dimensional process‐based lake model MyLake for simulating carbon dioxide (CO2) dynamics of a boreal lake. We calibrated the model for Lake Kuivajärvi, a small humic boreal lake, for the years 2013–2014, using the extensive data available on carbon inflow and concentrations of water column CO2 and dissolved organic carbon. The lake is a constant source of CO2 to the atmosphere in the present climate. We studied the potential effects of climate change‐induced warming on lake CO2 concentration and air‐water flux using downscaled air temperature data from three recent‐generation global climate models with two alternative representative concentration pathway forcing scenarios. Literature estimates were used for climate change impacts on the lake inflow. The scenario simulations showed a 20–35% increase in the CO2 flux from the lake to the atmosphere in the scenario period 2070–2099 compared to the control period 1980–2009. In addition, we estimated possible implications of different changes in terrestrial inorganic and organic carbon loadings to the lake. The scenarios with plausible increases of 10% and 20% in CO2 and dissolved organic carbon loadings, respectively, produced increases of 2.1–2.5% and 2.2–2.3% in the annual CO2 flux.

Kluge, T., John, C.M., Boch, R., Kele, S., 2018. Assessment of factors controlling clumped isotopes and δ18O values of hydrothermal vent calcites. Geochemistry, Geophysics, Geosystems 19, 1844-1858.

https://doi.org/10.1029/2017GC006969

The clumped isotope composition of CaCO3 (Δ47) is a geochemical proxy that can provide mineral formation temperatures and, together with measured carbonate δ18O, inferred fluid δ18O values. Under natural conditions, carbonates form within a relatively wide pH range and varying growth rates which are typically not reflected in laboratory‐based calibrations (mostly ∼pH 8, moderate growth rates). A pH and growth‐rate dependence is known for oxygen isotopes and was also postulated for clumped isotopes. Theoretical predictions suggest that Δ47 values could lie between the carbonate equilibrium value and the value inherited from the dissolved inorganic carbon (predicted offset: +0.04‰ pH < 4 and −0.025‰ at high pH > 12). Here we test whether pH (in addition to temperature) is recorded in the carbonate clumped isotope composition using modern calcites from natural travertine‐forming streams and scales precipitated in pipes of deep geothermal wells from Italy, Hungary, and Turkey (pH: 6.1–7.5, T: 33–100°C). Although a comparison of all samples with expected equilibrium values in this pH range and known formation temperatures reveals only an insignificant Δ47 offset (0.006 ± 0.004‰, 1SE, n = 9), the clumped isotope values of samples with the highest growth rates (0.014 ± 0.007‰, 1SE, n = 5) are consistent with the theoretical prediction attributable to pH of 0.01‰. Similarly, deviations in δ18O of up to −2‰ follow a growth‐rate dependence. This field‐based study shows that pH‐related effects are mostly small for Δ47 in the subsurface environment at lower pH and that high mineral growth rates control the magnitude of this disequilibrium.

Knittelfelder, O., Traikov, S., Vvedenskaya, O., Schuhmann, A., Segeletz, S., Shevchenko, A., Shevchenko, A., 2018. Shotgun lipidomics combined with laser capture microdissection: A tool to analyze histological zones in cryosections of tissues. Analytical Chemistry 90, 9868-9878.


Shotgun analysis provides a quantitative snapshot of the lipidome composition of cells, tissues, or model organisms; however, it does not elucidate the spatial distribution of lipids. Here we demonstrate that shotgun analysis could quantify low-picomole amounts of lipids isolated by laser capture microdissection (LCM) of hundred micrometer-sized histological zones visualized at the cryosections of tissues. We identified metabolically distinct periportal (pp) and pericentral (pc) zones by immunostaining of 20 μm thick cryosections of a healthy mouse liver. LCM was used to ablate, catapult, and collect the tissue material from 10 to 20 individual zones covering a total area of 0.3–0.5 mm2 and containing ca. 500 cells. Top-down shotgun profiling relying upon computational stitching of 61 targeted selective ion monitoring (t-SIM) spectra quantified more than 200 lipid species from 17 lipid classes including glycero- and glycerophospholipids, sphingolipids, cholesterol esters, and cholesterol. Shotgun LCM revealed the overall commonality of the full lipidome composition of pp and pc zones along with significant (p < 0.001) difference in the relative abundance of 13 lipid species. Follow-up proteomics analyses of pellets recovered from an aqueous phase saved after the lipid extraction identified 13 known and 7 new protein markers exclusively present in pp or in pc zones and independently validated the specificity of their visualization, isolation, and histological assignment.

Kolesnikov, A.V., Rogov, V.I., Bykova, N.V., Danelian, T., Clausen, S., Maslov, A.V., Grazhdankin, D.V., 2018. The oldest skeletal macroscopic organism Palaeopascichnus linearis. Precambrian Research 316, 24-37.


The existing problems regarding the phylogenetic resolution of Ediacaran macroscopic organisms stem from a failure to factor-in the information captured through different ‘taphonomic windows’. Here we integrate the information from sandstone- and limestone-hosted occurrences of the fossil

Palaeopascichnus linearis that together show a conspicuously greater range of taxonomic and taphonomic variation. The limestone-hosted material comes from a new locality discovered on the northwestern slope of the Olenek Uplift in Arctic Siberia that characterises the uppermost Ediacaran strata of the Khatyspyt Formation, Khorbusuonka Group. Detailed taphonomic and morphodynamic studies of the fossil material revealed evidence of possible chamber wall agglutination and growth through addition of new chambers with little sideway growth. Palaeopascichnus linearis outlived the intra-Ediacaran (∼550 Myr ago) drop in species richness, the advent of bilaterians, and the increase in complexity of burrowing behaviour in metazoans. It remains to be seen whether or not the remarkable ecological success achieved by Palaeopascichnus linearis during the times of rich evolutionary experimentation has anything to do with the invention of an agglutinated test. Palaeopascichnus poses major scientific challenges, and it is now clear that such preservation as occurs in Siberia may hold the answer to what they were, how they lived and what they were related to.

Kosior, D., Ngo, E., Xu, Y., 2018. Aggregates in paraffinic froth treatment: Settling properties and structure. Energy & Fuels 32, 8268-8276.


The settling rate of aggregates formed during paraffinic froth treatment depends strongly on process conditions. This work examined the influences of process temperature, solvent-to-bitumen ratio (S/B), and type of solvent used on the settling rate. Experiments were performed at temperatures ranging from 30 to 90 °C and various S/Bs, using isopentane, n-pentane, and n-hexane as paraffinic solvents. Based on studies of the settling rate, two factors can be emphasized. First, process temperature has the greatest influence on the settling rate of aggregates. Second, for a given solvent and temperature, increasing S/B results in an increase of the settling rate. Study of the aggregates formed during paraffinic froth treatment allowed for better understanding of the phenomena affecting the settling rate. Besides developing an aggregate sampling method based on solubility parameters, experimental procedures for determining structural parameters were successfully applied.

Kostyukevich, Y., Zherebker, A., Vlaskin, M.S., Borisova, L., Nikolaev, E., 2018. Microprobe for the thermal analysis of crude oil coupled to photoionization Fourier transform mass spectrometry. Analytical Chemistry 90, 8756-8763.


We present the simple microprobe for the investigation of crude oil by a thermal desorption photoionization coupled to Orbitrap mass spectrometry. The droplet of crude oil was placed on the heating element with controllable temperature. The temperature was linearly increased, and crude oil vapors were ionized by a vacuum ultraviolet (VUV) lamp and detected by Orbitrap mass spectrometer. Use of modified Orbitrap allowed introduction of the heating element and VUV lamp directly into the ion funnel and performing experiment not only at atmosphere pressure but also at 20, 10, and 5 torr. We observed that at high pressure protonated CHN compounds dominate in the spectrum, while at the low pressure CH compounds dominate. Similar to previously reported thermogravimetry coupled to photoionization or chemical ionization mass spectrometry systems we were able to separate compounds with different desorption energy and reliably detect low-abundant compounds. Also, we were able to determine the desorption temperature for each compound of the crude oil. We found that temperature of desorption increases linearly with m/z for compounds that belong to the same homology series (same Kendrick mass defect). This may serve as indirect evidence that such compounds differ only by the length of aliphatic chains attached to some basic structure.

Kujala, K., Mikkonen, A., Saravesi, K., Ronkanen, A.-K., Tiirola, M., 2018. Microbial diversity along a gradient in peatlands treating mining-affected waters. FEMS Microbiology Ecology 94, Article fiy145.

http://dx.doi.org/10.1093/femsec/fiy145

Peatlands are used for the purification of mining-affected waters in Northern Finland. In Northern climate, microorganisms in treatment peatlands (TPs) are affected by long and cold winters, but studies about those microorganisms are scarce. Thus, the bacterial, archaeal and fungal communities along gradients of mine water influence in two TPs were investigated. The TPs receive waters rich in contaminants, including arsenic (As), sulfate (SO4

2−) and nitrate (NO3−). Microbial diversity was high

in both TPs, and microbial community composition differed between the studied TPs. Bacterial communities were dominated by Proteobacteria, Actinobacteria, Chloroflexi and Acidobacteria, archaeal communities were dominated by Methanomicrobia and the Candidate phylum Bathyarchaeota, and fungal communities were dominated by Ascomycota (Leotiomycetes, Dothideomycetes, Sordariomycetes). The functional potential of the bacterial and archaeal communities in TPs was predicted using PICRUSt. Sampling points affected by high concentrations of As showed higher relative abundance of predicted functions related to As resistance. Functions potentially involved in nitrogen and SO4

2− turnover in TPs were predicted for both TPs. The results obtained in this study indicate that (i) diverse microbial communities exist in Northern TPs, (ii) the functional potential of the peatland microorganisms is beneficial for contaminant removal in TPs and (iii) microorganisms in TPs are likely well-adapted to high contaminant concentrations as well as to the Northern climate.

Kumar, J., Mendhe, V.A., Kamble, A.D., Bannerjee, M., Mishra, S., Singh, B.D., Mishra, V.K., Singh, P.K., Singh, H., 2018. Coalbed methane reservoir characteristics of coal seams of south Karanpura coalfield, Jharkhand, India. International Journal of Coal Geology 196, 185-200.


Coalbed methane has emerged as a viable natural gas resource in India since 2007. The understanding of gas genesis kinetics, storage mechanisms and the geological controls is vital for exploration and successful recovery of gas in a cost-effective manner. In this respect, a multidisciplinary analytical approach including gas content, stable isotopes (δ13C1), hydrocarbons distribution, reconstruction of original organic matter, chemical properties, sorption kinetics and the role of petrographic constituents have been assessed. The volatile matter content varies from 20.2 to 32.1 wt%; indicating medium volatile to high volatile bituminous rank of coal with the maximum vitrinite reflectance (VRo%) ranging from 0.63 to 0.98%. The studied coals are vitrinite rich and contains vitrinite group macerals in the range of 41–65 vol%. Dendritic micro-fractures are confined to vitrite microlithotype, and secondary mineralization helps preserve fracture connectivity. The average gas content of coal seams is 2.06 cc/g. The increase in gas content values per 100 m is about 0.38 cc/g emphasizing escape and migration of hydrocarbons during restructuring and tectonic activities in the basin. The relationship of C3/C1 and C2/C1 ratios is indicating that the hydrocarbons in desorbed gas originated from the thermogenic process. The large concentration of methane in desorbed gas and its stable isotope signatures (δ13C1 < −40‰) also indicates the thermogenic origin of gases in coal seams. Few desorbed gas samples have been found in the mixed gas region, which may be due to the influx of fresh water carrying bacteria leading to the generation of biogenic gases and subsequent mixing with the sorbed thermogenic gases. The values of S1 (0.19–0.78 mg HC/g) and S2 (10.31–25.63 mg HC/g) indicate excellent source rock potentials. The positive correlation of original hydrogen index (HIO)

with present-day hydrogen index (HIPD) and original organic content (TOCO) with present-day organic content (TOCPD) suggests uniform consistency in organic carbon conversion to hydrocarbons.

The gas content compared with sorption capacity reveals the undersaturation of coal seams. The experimental results summarize that the low gas content is a critical issue. Similarly, the low, quality and quantity of CH4 may affect the exploration and recovery of methane in the long term into this basin. But, the low values of sorption time (0.12–6.65 days) signifies good diffusion characteristics that may support the recovery of gas. Finally, it is concluded that depth of occurrence, maturity and pore/cleats associated with microconstituents control the gas accumulation and transport in coal seam reservoirs of South Karanpura coalfield.



Effective development of shale oil/gas reservoirs depends on the success of hydraulic fracturing. Mineralogy and morphology play a very important role in establishing brittleness and therefore controlling its hydraulic fracturing characteristics. In this paper, mineralogical and morphological characteristics of the Older Cambay Shale and the top Olpad Formation from the northern Cambay Basin, India have been characterized using well logs, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDS or EDX) and atomic force microscopy (AFM) with the objective of identifying the fracturing potential of the units. Presence of mixed argillaceous mudstone, silica-rich argillaceous mudstone to argillaceous siliceous mudstone in the studied shale samples shows that the area under investigation is compositionally similar to the high clay facies of Marcellus and Barnett shale systems having low fracability. The studied formation is rich in kaolinite and chlorite, which aggregately contribute half of mineral composition ranging from 43 to 56%. Quartz, feldspar and mica combined to add approximately 30–43%, while siderite and magnesite varied between 8 and 12%. The interpreted results of mineralogical brittleness are supported by log based geomechanical properties. FESEM images at micro to nanoscale confirm the presence of various minerals with distinct crystal structure, along with inter-and-intra particle pores in the matrix. AFM scan at the nano scale shows mesopores ranging from 12 to 19 nm, with an average pore diameter of 17.57 nm and areal coverage of 10.9%. The log derived mechanical properties correlate with the mineralogy-based brittleness index (BI) of the studied shales indicating that the formations lie in the low to medium range of fracability. High clay content and low to moderate BI are likely to complicate the fracturing process of the potential resource rich area. Outcome of the present investigation demonstrates the limited shale oil/gas potential in the study area; however an extensive exploration program may unlock some sweet spots in the basin with distinctly different characteristics.

Kumar, S., Herrmann, M., Blohm, A., Hilke, I., Frosch, T., Trumbore, S.E., Küsel, K., 2018. Thiosulfate- and hydrogen-driven autotrophic denitrification by a microbial consortium enriched from groundwater of an oligotrophic limestone aquifer. FEMS Microbiology Ecology 94, Article fiy141.


Despite its potentially high relevance for nitrate removal in freshwater environments limited in organic carbon, chemolithoautotrophic denitrification has rarely been studied in oligotrophic groundwater. Using thiosulfate and H2 as electron donors, we established a chemolithoautotrophic

enrichment culture from groundwater of a carbonate-rock aquifer to get more insight into the metabolic repertoire, substrate turnover, and transcriptional activity of subsurface denitrifying consortia. The enriched consortium was dominated by representatives of the genus Thiobacillus along with denitrifiers related to Sulfuritalea hydrogenivorans, Sulfuricella denitrificans, Dechloromonas sp. and Hydrogenophaga sp., representing the consortium's capacity to use multiple inorganic electron donors. Microcosm experiments coupled with Raman gas spectroscopy demonstrated complete denitrification driven by reduced sulfur compounds and hydrogen without formation of N2O. The initial nitrate/thiosulfate ratio had a strong effect on nosZ transcriptional activity and on N2 formation, suggesting similar patterns of the regulation of gene expression as in heterotrophic denitrifiers. Sequence analysis targeting nirS and nosZ transcripts identified Thiobacillus denitrificans-related organisms as the dominant active nirS-type denitrifiers in the consortium. An additional assessment of the nirS-type denitrifier community in the groundwaterclearly confirmed the potential for sulfur- and hydrogen-dependent chemolithoautotrophic denitrification as important metabolic feature widely spread among subsurface denitrifiers at the Hainich Critical Zone Exploratory.



Bacteriohopanepolyols (BHPs) are characterized by a large structural diversity, although methodological constraints have limited investigations of the occurrence of isomers among composite BHPs in environmental samples. Here, we describe a novel chromatography method that uses three serial Phenomenex Kinetex C18 columns to successfully resolve new structural isomers of BHPs commonly observed in marine sediment samples. The investigated samples consistently contain a high diversity of BHP isomers, but their relative abundances differ significantly between samples. These differences in relative abundance have potential to reflect different environmental conditions such as depositional setting or redox conditions. The improved BHP resolution and baseline separation of the new method is promising for accurate quantification and future environmental proxy development and compound-specific isotope work.

Kwiatkowski, M., Krösser, D., Wurlitzer, M., Steffen, P., Barcaru, A., Krisp, C., Horvatovich, P., Bischoff, R., Schlüter, H., 2018. Application of displacement chromatography to online two-dimensional liquid chromatography coupled to tandem mass spectrometry improves peptide separation efficiency and detectability for the analysis of complex proteomes. Analytical Chemistry 90, 9951-9958.


The complexity of mammalian proteomes is a challenge in bottom-up proteomics. For a comprehensive proteome analysis, multidimensional separation strategies are necessary. Online two-dimensional liquid chromatography–tandem mass spectrometry (2D-LC-MS/MS) combining strong cation exchange (SCX) in the first dimension with reversed-phase (RP) chromatography in the second dimension provides a powerful approach to analyze complex proteomes. Although the combination of SCX with RP chromatography provides a good orthogonality, only a moderate separation is achieved in the first dimension for peptides with two (+2) or three (+3) positive charges. The aim of this study was to improve the performance of online SCX-RP-MS/MS by applying displacement chromatography to the first separation dimension. Compared to gradient chromatography mode (GCM), displacement chromatography mode (DCM) was expected to improve the separation of +2-

peptides and +3-peptides, thus reducing complexity and increasing ionization and detectability. The results show that DCM provided a separation of +2-peptides and +3-peptides in remarkably sharp zones with a low degree of coelution, thus providing fractions with significantly higher purities compared to GCM. In particular, +2-peptides were separated over several fractions, which was not possible to achieve in GCM. The better separation in DCM resulted in a higher reproducibility and significantly higher identification rates for both peptides and proteins including a 2.6-fold increase for +2-peptides. The higher number of identified peptides in DCM resulted in significantly higher protein sequence coverages and a considerably higher number of unique peptides per protein. Compared to conventionally used salt-based GCM, DCM increased the performance of online SCX-RP-MS/MS and enabled comprehensive proteome profiling in the low microgram range.

Lancet, D., Zidovetzki, R., Markovitch, O., 2018. Systems protobiology: origin of life in lipid catalytic networks. Journal of The Royal Society Interface 15, Article 20180159.

http://rsif.royalsocietypublishing.org/content/15/144/20180159.abstract

Life is that which replicates and evolves, but there is no consensus on how life emerged. We advocate a systems protobiology view, whereby the first replicators were assemblies of spontaneously accreting, heterogeneous and mostly non-canonical amphiphiles. This view is substantiated by rigorous chemical kinetics simulations of the graded autocatalysis replication domain (GARD) model, based on the notion that the replication or reproduction of compositional information predated that of sequence information. GARD reveals the emergence of privileged non-equilibrium assemblies (composomes), which portray catalysis-based homeostatic (concentration-preserving) growth. Such a process, along with occasional assembly fission, embodies cell-like reproduction. GARD pre-RNA evolution is evidenced in the selection of different composomes within a sparse fitness landscape, in response to environmental chemical changes. These observations refute claims that GARD assemblies (or other mutually catalytic networks in the metabolism first scenario) cannot evolve. Composomes represent both a genotype and a selectable phenotype, anteceding present-day biology in which the two are mostly separated. Detailed GARD analyses show attractor-like transitions from random assemblies to self-organized composomes, with negative entropy change, thus establishing composomes as dissipative systems—hallmarks of life. We show a preliminary new version of our model, metabolic GARD (M-GARD), in which lipid covalent modifications are orchestrated by non-enzymatic lipid catalysts, themselves compositionally reproduced. M-GARD fills the gap of the lack of true metabolism in basic GARD, and is rewardingly supported by a published experimental instance of a lipid-based mutually catalytic network. Anticipating near-future far-reaching progress of molecular dynamics, M-GARD is slated to quantitatively depict elaborate protocells, with orchestrated reproduction of both lipid bilayer and lumenal content. Finally, a GARD analysis in a whole-planet context offers the potential for estimating the probability of life's emergence. The invigorated GARD scrutiny presented in this review enhances the validity of autocatalytic sets as a bona fide early evolution scenario and provides essential infrastructure for a paradigm shift towards a systems protobiology view of life's origin.

Landman, N.H., Cochran, J.K., Slovacek, M., Larson, N.L., Garb, M.P., Brezina, J., Witts, J.D., 2018. Isotope sclerochronology of ammonites (Baculites Compressus) from methane seep and non-seep sites in the Late Cretaceous Western Interior Seaway, USA: Implications for ammonite habitat and mode of life. American Journal of Science 318, 603-639.


Ammonites, as well as other fauna, were common in methane seeps of the Late Cretaceous Western Interior Seaway (WIS) of North America. Biogeochemical processes at the seeps, in particular the anaerobic oxidation of methane, produced a dissolved inorganic carbon reservoir with a low δ13C, manifested in the carbon isotope composition of the inorganic calcium carbonate concretions associated with the seeps and recorded in well-preserved shells of ammonites documented at the sites. Detailed sclerochronological sampling of six well-preserved specimens of Baculites compressus collected at seep sites in the Pierre Shale of South Dakota reveals three patterns that can be explained by reference to two specimens of the same species collected at age-equivalent non-seep sites. Three of the specimens exhibit uniformly low values of δ13C that are significantly different (unpaired t-test, p < .0001) from similarly sized specimens of the same species collected at age-equivalent non-seep sites, suggesting that these ammonites lived at the seeps during the time interval over which the shell was secreted (adult portion of the shell). Two of the specimens collected from a seep site exhibit values of δ13C consistent with early ontogeny at a non-seep site followed by later ontogeny at a seep site. The values of δ18O of all the specimens reveal water temperatures of 16 to 28 °C. One small juvenile (15 mm long) collected at a seep site exhibits higher values of δ13C consistent with a non-seep environment, but values of δ18O that indicate very warm or slightly brackish water, suggesting that this animal lived in surface waters during its early ontogeny and died soon after arriving at the seep. Our results demonstrate that seep fluids affected the geochemistry of the water column above the seeps and that seeps provided habitats for ammonites in the WIS. Thus, although ammonites were mobile animals, they probably exploited a low-energy life style, remaining at the same site for extended periods of time.

Lang, X., Shen, B., Peng, Y., Xiao, S., Zhou, C., Bao, H., Kaufman, A.J., Huang, K., Crockford, P.W., Liu, Y., Tang, W., Ma, H., 2018. Transient marine euxinia at the end of the terminal Cryogenian glaciation. Nature Communications 9, Article 3019.

https://doi.org/10.1038/s41467-018-05423-x

Termination of the terminal Cryogenian Marinoan snowball Earth glaciation (~650–635 Ma) is associated with the worldwide deposition of a cap carbonate. Modeling studies suggest that, during and immediately following deglaciation, the ocean may have experienced a rapid rise in pH and physical stratification followed by oceanic overturn. Testing these predictions requires the establishment of a high-resolution sequence of events within sedimentary records. Here we report the conspicuous occurrence of pyrite concretions in the topmost Nantuo Formation (South China) that was deposited in the Marinoan glacial deposits. Sedimentary facies and sulfur isotope data indicate pyrite precipitation in the sediments with H2S diffusing from the overlying sulfidic/euxinic seawater and Fe (II) from diamictite sediments. These observations suggest a transient but widespread presence of marine euxinia in an ocean characterized by redox stratification, high bioproductivity, and high-fluxes of sulfate from chemical weathering before the deposition of the cap carbonate.

Lashkarbolooki, M., Ayatollahi, S., 2018. Investigation of ionic liquids based on pyridinium and imidazolium as interfacial tension reducer of crude oil−water and their synergism with MgCl2. Journal of Petroleum Science and Engineering 171, 414-421.


Ionic liquids (ILs) can be tailored as chemical surfactants and surface active agents to reduce the interfacial tension (IFT) of crude oil/aqueous solutions for enhanced oil recovery processes. The current investigation was aimed to explore the nature of ingenious active agents in crude oil, including asphaltene and resin, and their possible interactions with two families of ILs, namely

pyridinium and imidazolium, on the IFT of crude oil/aqueous solutions, both in the presence and absence of MgCl2. To the best of our knowledge, the effect of crude oil type on the IFT of crude oil/aqueous solution containing salts and IL has not been ever investigated. Accordingly, IFTs of light, medium and heavy crude oils (labeled as LCO, MCO and HCO, respectively) and two ILs, i.e. [C8mim] [Cl] and [C8Py] [Cl] were measured. In addition, the effects of the total acid number of crude oils, the amount of ingenious active agents in the crude oils as well as their major structural, molecular parameters such as hydrogen/carbon ratio and type and amount of heteroatoms (i.e. nitrogen, sulfur and oxygen) were investigated. The obtained results indicated that the performance of ILs was influenced by the crude oil and IL types. In details, the aromatic section of cationic part and their interactions with heteroatoms of crude oil showed the most influential role on the IFT variation.

Lattaud, J., Lo, L., Huang, J.-J., Chou, Y.-M., Gorbarenko, S.A., Sinninghe Damsté, J.S., Schouten, S., 2018. A comparison of late quaternary organic proxy-based paleotemperature records of the central Sea of Okhotsk. Paleoceanography and Paleoclimatology 33, 732-744.

https://doi.org/10.1029/2018PA003388

Abstract The long-chain diol index (LDI) is a new organic sea surface temperature (SST) proxy based on the distribution of long-chain diols. It has been applied in several environments but not yet in subpolar regions. Here we tested the LDI on surface sediments and a sediment core from the Sea of Okhotsk, which is the southernmost seasonal sea ice-covered region in the Northern Hemisphere, and compared it with other organic temperature proxies, that is, Uk′37 and TEXL86. In the surface sediments, the LDI is correlated with autumn SST, similar to the Uk′37 but different from the TEXL86 that correlates best with summer sea subsurface temperature. Remarkably, the obtained local LDI calibration was significantly different from the global core-top calibration. We used the local LDI calibration to reconstruct past SST changes in the central Sea of Okhotsk. The LDI-SST record shows low glacial (Marine Isotope Stage, MIS 2, 4, and 6) and high interglacial (MIS 1 and MIS 5) temperatures and follows the same pattern as the Uk′37-SST and a previously published TEXL86 temperature record. Similar to the modern situation, the reconstructed temperatures during the interglacials likely reflect different seasons, that is, summer for the TEXL86 and autumn for Uk′37 and LDI. During glacials, the reconstructed temperatures of all three proxies are similar to each other, likely reflecting summer temperatures as this was the only season free of sea ice. Our results suggest that the LDI is a suitable proxy to reconstruct subpolar seawater temperatures.

Leach, N.J., Millar, R.J., Haustein, K., Jenkins, S., Graham, E., Allen, M.R., 2018. Current level and rate of warming determine emissions budgets under ambitious mitigation. Nature Geoscience 11, 574-579.

https://doi.org/10.1038/s41561-018-0156-y

Some of the differences between recent estimates of the remaining budget of carbon dioxide (CO2) emissions consistent with limiting warming to 1.5 °C arise from different estimates of the level of warming to date relative to pre-industrial conditions, but not all. Here we show that, for simple geometrical reasons, the combination of both the level and rate of human-induced warming provides a remarkably accurate prediction of remaining emission budgets to peak warming across a broad range of scenarios, if budgets are expressed in terms of CO2-forcing-equivalent emissions. These in turn predict CO2 emissions budgets if (but only if) the fractional contribution of non-CO2 drivers to warming remains approximately unchanged, as it does in some ambitious mitigation scenarios, indicating a best-estimate remaining budget for 1.5 °C of about 22 years’ current emissions from mid-2017, with a ‘likely’ (1 standard error) range of 13–32 years. This provides a simple, transparent and

model-independent metric of progress towards an ambitious temperature stabilization goal that could be used to inform the Paris Agreement stocktake process. It is less applicable to less ambitious goals. Alternative definitions of current warming and scenarios for non-CO2 drivers give lower 1.5 °C budgets. Lower budgets based on the MAGICC simple modelling system widely used in integrated assessment studies reflect its relatively high simulated current warming rates.

Ledesma, J.L.J., Kothawala, D.N., Bastviken, P., Maehder, S., Grabs, T., Futter, M.N., 2018. Stream dissolved organic matter composition reflects the riparian zone, not upslope soils in boreal forest headwaters. Water Resources Research 54, 3896-3912.

https://doi.org/10.1029/2017WR021793

Abstract: Despite the strong quantitative evidence that riparian zones (RZs) are the dominant source of dissolved organic carbon (DOC) to boreal streams, there is still a debate about the potential contribution of upslope areas to fluvial carbon export. To shed new light into this debate, we investigated the molecular composition of dissolved organic matter (DOM) in four upslope‐riparian‐stream transects in a Northern Swedish forest catchment using absorbance (A254/A365 and SUVA254) and fluorescence (fluorescence and freshness indices) metrics. Based on these metrics, our results indicate that stream water DOM molecular composition resembles that of RZs and significantly differs from that of upslope areas. The resemblance between stream and riparian DOM was most apparent for the “Dominant Source Layer” (DSL), a narrow RZ stratum that, theoretically, contributes the most to solute and water fluxes to streams. Spectroscopic characterization based on traditional interpretations of the metrics suggested that mineral upslope (podzol) DOM is less aromatic, more microbially derived, and more recently produced than organic riparian (histosol) and stream DOM. We conclude that RZs, and specifically DSLs, are the main sources of DOC to boreal headwater streams and potentially to other streams located in low‐gradient, organic matter‐rich catchments.

Plain Language Summary: Understanding carbon cycling in natural ecosystems is critical because ongoing climate change can promote the release of previously stored carbon in forest soils to streams and rivers, with the potential to form carbon dioxide, the main greenhouse gas. This is particularly important in boreal ecosystems, which are the largest stores of terrestrial carbon in the world. In this study, we identify the near‐stream area, the so‐called riparian zone, as the main source of carbon from boreal forest soils to streams. We provide qualitative data to support this, which together with previous quantitative analyses, make up enough evidence to support that the riparian zone is the main source of carbon to streams. As there is still a debate about the potential contribution of other areas in the ecosystem to the fluvial carbon export, our study importantly highlights that the riparian zone should be the focus of scientific assessments and management strategies in relation to carbon exports in surface waters.

Lee, C.J.D., McMullan, P.E., O’Kane, C.J., Stevenson, A., Santos, I.C., Roy, C., Ghosh, W., Mancinelli, R.L., Mormile, M.R., McMullan, G., Banciu, H.L., Fares, M.A., Benison, K.C., Oren, A., Dyall-Smith, M.L., Hallsworth, J.E., 2018. NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats. FEMS Microbiology Reviews 42, 672-693.

http://dx.doi.org/10.1093/femsre/fuy026

NaCl-saturated brines such as saltern crystalliser ponds, inland salt lakes, deep-sea brines and liquids-of-deliquescence on halite are commonly regarded as a paradigm for the limit of life on Earth. There are, however, other habitats that are thermodynamically more extreme. Typically, NaCl-saturated environments contain all domains of life and perform complete biogeochemical cycling. Despite their

reduced water activity, ∼0.755 at 5 M NaCl, some halophiles belonging to the Archaea and Bacteria exhibit optimum growth/metabolism in these brines. Furthermore, the recognised water-activity limit for microbial function, ∼0.585 for some strains of fungi, lies far below 0.755. Other biophysical constraints on the microbial biosphere (temperatures of >121°C; pH > 12; and high chaotropicity; e.g. ethanol at >18.9% w/v (24% v/v) and MgCl2 at >3.03 M) can prevent any cellular metabolism or ecosystem function. By contrast, NaCl-saturated environments contain biomass-dense, metabolically diverse, highly active and complex microbial ecosystems; and this underscores their moderate character. Here, we survey the evidence that NaCl-saturated brines are biologically permissive, fertile habitats that are thermodynamically mid-range rather than extreme. Indeed, were NaCl sufficiently soluble, some halophiles might grow at concentrations of up to 8 M. It may be that the finite solubility of NaCl has stabilised the genetic composition of halophile populations and limited the action of natural selection in driving halophile evolution towards greater xerophilicity. Further implications are considered for the origin(s) of life and other aspects of astrobiology.

Leila, M., Moscariello, A., 2018. Depositional and petrophysical controls on the volumes of hydrocarbons trapped in the Messinian reservoirs, onshore Nile Delta, Egypt. Petroleum 4, 250-267.


The Messinian sequence in the Nile Delta hosts the most prolific hydrocarbon reservoirs, and is therefore of great importance from the aspect of nonrenewable fuel sources exploration and development strategies. This study presents an investigation for the differential impacts of the depositional and petrophysical attributes on the hydrocarbon volumes trapped in the Messinian reservoirs. Analyses of the pressure data and pressure gradients revealed hydraulically-connected and homogeneous Messinian reservoir rocks. The amounts of Stock Tank Oil and Gas Initially In Places (STOIPP & GIIP) are typically controlled by the depositional primary attributes (matrix content and grain size) which induce several reservoir heterogeneities. The Lower Messinian Qawasim reservoir is subdivided into two main zones: the distal deltaic (zone 1) prograded into proximal deltaic facies (zone 2). The petrophysical reservoir quality in terms of porosity, permeability and water saturation increases upward from zone 1 to zone 2. These are largely controlled by the depositional attributes, and therefore zone 2 with a minimum matrix content, coarse-grained sandstones and mega pore spaces (>150 μm) hosts almost 90% of the STOIIP and 100% of the GIIP. Notably, approximately 78% and 65% of the total STOIIP and GIIP, respectively are confined within the coarse-grained delta-plain distributary channels of zone 2. Similarly, the fluvial sediments (zone 1) of the Upper Messinian Abu Madi Formation host 78% of the GIIP in West Al-Khilala Field and the other 22% is trapped in the overlying zone 2 and is mostly distributed within the sand-prone tidal channel and tidal sand bars facies. The channel width/thickness (W/T) ratio largely controls the STOIIP and GIIP values. STOIIP and GIIP display a progressive linear increase with increasing the channel width. This is likely due to increasing the percentage of the good reservoir quality facies within the geologic model as well as increasing the reservoir connectivity with increasing the channel width.


https://doi.org/10.1134/S1028334X18070243

The interaction of biogeochemical sulfur and carbon cycles in water bodies has been studied by the different authors and methods, including the use of 35S and 14C radioactive tracers. The main reactions of sulfur and carbon interaction by the example of the Black Sea (sulfate reduction, methanogenesis, aerobic and anaerobic methane oxidation) are considered. Based on the experimental radioisotope

data, the annual microbial production of H2S and CH4 in the water column of the Black Sea is estimated. The average annual production of CH4 is 3.8% of the annual production of H2S. The share of migration methane from the bottom sediments (seeps, mud volcanoes, etc.) is approximately 2% of the total dissolved methane pool. Original Russian Text © A.Yu. Lein, M.V. Ivanov, 2018, published in Doklady Akademii Nauk, 2018, Vol. 481, No. 3.

Lengfelder, F., Grupe, G., Stallauer, A., Huth, R., Söllner, F., 2019. Modelling strontium isotopes in past biospheres – Assessment of bioavailable 87Sr/86Sr ratios in local archaeological vertebrates based on environmental signatures. Science of The Total Environment 648, 236-252.


87Sr/86Sr isotopic ratios in skeletal remains of archaeological vertebrates are used for provenance analysis since long. However, the definition of the past bioavailable isotopic ratio at the site of recovery is not known beforehand and geological maps can provide no more than gross expectations. Therefore, the assessment of the “local Sr isotopic signature” is still of crucial importance. In this study, we present a tool for the prediction of such local isotopic signatures by creating a concentration weighted mixing model that links lithospheric, biospheric, and atmospheric strontium per site. The major strontium sources and their input into an animal's body were assessed by choosing elemental strontium and its isotopic signature in groundwater, soil, vegetation, and precipitation as components for the mixing model, augmented by literature values. The model was applied to 24 sites located in the alpine transect of the Inn-Eisack-Adige-Brenner passage across the European Alps, a passage used since the Mesolithic. Predicted local bioavailable 87Sr/86Sr ratios were compared with measured values from locally excavated archaeozoological bone samples from three taxa of large and mainly residential vertebrates (cattle, pig, red deer) to verify the models' accuracy. With regard to the fact that the environmental samples predict the past local bioavailable 87Sr/86Sr at a specific site while the vertebrates had different and species-specific home ranges, thereby integrating strontium from a region of primarily unknown size, the model is capable of assigning reasonable expectation values. For 11 sites, up to 100% of the vertebrate isotopic signatures were correctly predicted. Mismatches at the remaining sites are explainable by special environmental factors, and also the fact that some import of animals can never be excluded beforehand. Suggestions for site-specific adjustments of the model are made.



Organic-rich shale, which is a heterogeneous material, has been studied extensively from various perspectives. Among all the components that constitute shale, organic matter is less known in regards to its mechanical properties. Since organic matter is relatively the softer part compared to inorganic minerals, high concentrations of it can have a significant impact on bulk mechanical properties of the rock, which can affect field operations such as hydraulic fracturing. In this study, four shale samples from the Bakken Formation in Williston Basin, North Dakota, were examined by a combination of experimental methods including X-ray diffraction (XRD), Rock-Eval pyrolysis, optical and scanning electron microscopy (SEM) along with atomic force microscope (AFM). PeakForce Quantitative Nano-mechanical Mapping mode in AFM was used particularly, to map the modulus of organic matter in nano-scale. XRD analysis showed that quartz and clays are the main constituent minerals in the shale samples. Geochemical results showed that all samples are extremely organic-rich, and the

organic matter is mostly type II, varying from thermally immature to oil generation window. Elastic properties test results demonstrated that surface topographic features including pores, microfractures and grain boundaries would have a negative impact on AFM data, and a data filtering procedure was conducted on AFM data to get rid of wrong values. The elastic modulus of identified organic matter (bitumen and micrinite) was measured in the range of 7–23 GPa with a significant heterogeneity in a single studied organic particle and dependent upon the type of organic particle.

Li, C., Wang, L., Liu, H., 2018. Enhanced redox conductivity and enriched Geobacteraceae of exoelectrogenic biofilms in response to static magnetic field. Applied Microbiology and Biotechnology 102, 7611-7621.

https://doi.org/10.1007/s00253-018-9158-3

A possible approach to enhance the performance of microbial electrochemical system such as microbial fuel cells is to increase the conductivity of catalytic biofilms and thereby the direct extracellular electron transfer within the biofilms and from the electrode. In the present study, we evaluated the impact of static low-intensity magnetic field on the anodic biofilms in microbial fuel cells (MFCs). Results demonstrated that the application of a low-intensity magnetic field (105 and 150 mT) can significantly shorten the startup time and enhance the overall performance of single-chamber MFCs in terms of current density (300%) and power density (150%). In situ conductance evaluation indicated that short-term application of magnetic field can increase biofilm conductivity, although the long-term enhancements were likely results of increased conductivity of the anodic biofilms associated with enriched population of Geobacteraceae. The peak-manner response of conductivity over gate potentials and the positive response of mature biofilm conductance to low intensity of magnetic field support the redox conduction model of the conductive exoelectrogenic biofilms.

Li, F., Chang, Z., Khaing, K., Zhou, Y., Zhao, H., Liang, N., Zhou, D., Pan, B., Steinberg, C.E.W., 2019. Organic matter protection by kaolinite over bio-decomposition as suggested by lignin and solvent-extractable lipid molecular markers. Science of The Total Environment 647, 570-576.


The formation of organo-mineral complexes is essential in organic matter (OM) stabilization. However, limited studies have been conducted to systematically examine the mineral influence on the decomposition of plant residuals at a molecular level. In this study, pine needles and chestnut leaves were mixed with kaolinite at the weight ratio of 5:1. The controls were plant tissues without kaolinite. All the samples were incubated in the laboratory for one year. Molecular markers, including lignin-derived phenols (e.g. Vanilly units, syringyl units and cinnamyl units) and solvent-extractable lipids (e.g. n-alkanoic acid, n-alkanols and n-alkanes), were analyzed. The concentrations of lignin-derived phenols and lipid compounds were higher in the presence of kaolinite than without kaolinite. Lower degradation indexes, such as (Ad/Al)V (ratio of vanillic acid to vanillin) and CPI (carbon preference index of n-alkanoic acid and n-alkanes), were found in the kaolinite system. These results indicate that kaolinite reduced the OM decomposition. The addition of kaolinite also stabilized some carbohydrates from plants. Furthermore, the degradation of OM led to the generation of persistent free radicals, indicated by electron paramagnetic resonance (EPR) signals. The EPR signals were higher with than without kaolinite. We hypothesize that the adsorption of semiquinone or quinone radicals on kaolinite may limit their reaction with other OM moieties and thus extended their lifetimes. In addition to embedding OM in soil aggregates, our results provide direct evidence of another mineral protective mechanism of soil OM.

Li, G., Li, C., Li, X., Wei, N., 2018. Permeability experiments on the methane hydrate in quartz sands and its model verification. Natural Gas Industry B 5, 298-305.


The permeability of porous media is an important physical parameter that affects the exploitation of natural gas hydrate. At present, however, the measurement methods and porous media used for investigating the permeability are so different that neither well-recognized experiment methods nor measurement results are available yet. In this paper, a one-dimensional test apparatus was developed to measure the permeability of porous media with methane hydrate. By virtue of this apparatus, methane hydrate was generated and the flow rate and pressure difference of inflow liquid water were measured in a stable flow pattern. Then, based on the basic principle of the Darcy's Law, the permeability of 30–40 mesh quartz sands with a methane hydrate system was calculated using steady-state water injection. And the experimental results were obtained. First, this apparatus can provide the flow rates and pressure differences of stable fluid under constant pressures and temperatures, so it satisfies the basic conditions of the Darcy's Law and consequently the permeability is calculated. Second, with this apparatus, the methane hydrate saturation in permeability experiments can be controlled effectively, so that the reliability and repeatability of permeability measurement of methane hydrate bearing quartz sands are ensured. Third, methane hydrate crystals are formed and gradually grow in the pore center, occupying the pore space and blocking the flow channel. And the liquid effective permeability decreases sharply with the increase of methane hydrate saturation. Fourth, the permeability calculated by the Masuda, Dai and Li models is 13.0, 7.0 and 4.0, respectively and the calculated values are in accordance with the experimental results. These research results provide experimental data and a theoretical calculation basis for the quantification of fluid permeability of methane hydrate bearing porous media.

Li, H., Liu, G., Zhang, X., 2018. Analysis of kerosene-based endothermic hydrocarbon fuel using comprehensive two-dimensional gas chromatography coupled to mass spectrometry. Chinese Journal of Chromatography 36, 780-785.

http://www.chrom-china.com/EN/abstract/abstract14535.shtml

Hydrocarbon fuels are mainly composed of n-alkenes, iso-alkanes, cycloalkanes (primarily single-and double-ring), alkylbenzenes, indans, tetralins, naphthalene, and alkylnaphthalenes. Different hydrocarbon classes impart different properties to a fuel. An identification method of hydrocarbon classes in kerosene-based endothermic hydrocarbon fuel was established using comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS). Moreover, the corresponding quantitative determination was achieved using the effective carbon number correction factors of GC×GC-FID. The effects of the main chromatographic conditions such as the column system, program heating conditions, and modulation period on the separation of fuels were discussed. Nine hydrocarbon fuels were analyzed. The results showed that the contents of paraffin and cycloalkanes are consistent with the results obtained using the standard test method ASTM D2425. The relative error is within ±10%. The carbon content calculated using this method has an error of less than 0.5% compared with the elemental analysis method. This method does not require complicated pretreatment, and the sample can be injected directly after dilution. Compared with the traditional GC-MS, the operation is simple, and the differences among various samples can be observed intuitively, which helps in improving the performance of the fuel.

Li, J., Yu, T., Liang, X., Zhang, P., Chen, C., Zhang, J., 2017. Insights on the gas permeability change in porous shale. Advances in Geo-Energy Research 1, 69-73.


Due to abundant nanoscale pores developed in shale, gas flow in shale presents a complex dynamic process. This paper summarized the effects from effective stress increase, shale matrix shrinkage, gas slippage and Knudsen diffusion on the gas permeability change in shale during shale gas recovery. With the reduce in gas pressure, effective stress increase leads to the decline of the permeability in an exponential form; the permeability increases due to the shale matrix shrinkage induced by gas desorption; appearances of gas slippage and Knudsen diffusion cause an additional increase in the gas permeability particularly in small pores at low pressures. In addition, some reported models evaluating the shale permeability were reviewed preliminarily. Models considering these four effects may be potentially effective to evaluate the gas permeability change in shale.

Li, J.X., Yue, L.P., Roberts, A.P., Hirt, A.M., Pan, F., Guo, L., Xu, Y., Xi, R.G., Guo, L., Qiang, X.K., Gai, C.C., Jiang, Z.X., Sun, Z.M., Liu, Q.S., 2018. Global cooling and enhanced Eocene Asian mid-latitude interior aridity. Nature Communications 9, Article 3026.

https://doi.org/10.1038/s41467-018-05415-x

Tibetan Plateau uplift has been suggested as the main driving force for mid-latitude Asian inland aridity (AIA) and for deposition of thick aeolian sequences in northern China since the Miocene. However, the relationship between earlier AIA and Tibetan Plateau mountain building is uncertain because of a lack of corresponding thick aeolian sequences with accurate age constraints. We here present results for a continuous aeolian sequence that spans the interval from >51 to 39 Ma from the eastern Xorkol Basin, Altun Shan, northeastern Tibetan Plateau. The basal age of the studied sequence postdates initial uplift of the Tibetan Plateau by several million years. Our results indicate that the local palaeoclimate was teleconnected strongly to the overall global cooling pattern, so that local enhanced aridification recorded by the studied aeolian sequence is dominantly a response to global climatic forcing rather than plateau uplift.

Li, S., Zhang, K., Jia, N., Liu, L., 2018. Evaluation of four CO2 injection schemes for unlocking oils from low-permeability formations under immiscible conditions. Fuel 234, 814-823.


In this paper, four different injection schemes, i.e., CO2 continuous gas injection (CGI), gas injection (GI) + soaking, pulse injection, and injection-alternating-production (IAP), for the high-temperature and pressure CO2 immiscible flooding in low-permeability formations are experimentally studied. A series of comprehensive and optimum practical strategies with respect to the four immiscible CO2 injection processes in the low-permeability formations can be determined from this study. More specifically, a total of 10 immiscible coreflood tests are conducted at the injection pressure of 20.0 MPa and reservoir temperature of 130.0 °C by means of the four different injection schemes. The oil viscosity and density are experimentally measured to be reduced with the temperature increase and the minimum miscibility pressure is measured to be 30.0 MPa at 130.0 °C from the vanishing interfacial tension (VIT) technique. Among Tests No. 1–10 with the same experimental conditions, the measured oil recovery factor (ORF) of Test No. 9, which is the CO2 IAP with the injection rates of 0.5 cm3/min, is the highest at 69.06%. In Test No. 4, the CO2 GI + soaking at the injection rate of 0.5 cm3/min has the second highest ORF of 65.21%. Tests No. 1, 4, 7, and 9 at the injection rate of

0.5 cm3/min outperform other tests with the same injection scheme in terms of the ORF under the same experimental conditions but at larger injection rates. Thus, a small CO2 injection rate is beneficial to increase the ORF for all schemes except for the CO2 pulse injections. It is found that soaking is an important step for CO2 enhanced oil recovery at the immiscible conditions. Moreover, the smaller injection rate also contributes to the delay of CO2 breakthrough so that a higher ORF can be reached at a lower cost. Finally, the measured asphaltene and wax contents in the produced oil are found to reduce in the percentages of 33–51% and 14–25% from the beginning period to the end of the oil production.

Li, T., Hu, Y., Zhang, B., 2018. Biomineralization induced by Colletotrichum acutatum: A potential strategy for cultural relic bioprotection. Frontiers in Microbiology 9, 1884. doi: 10.3389/fmicb.2018.01884.


Colletotrichum acutatum is a fungus capable of biomineralization reported in our pervious study. In this paper, we compared the ability of this fungus to induce mineralization under different calcium sources, pH levels, and differing carbon availability. Here we found that organic acids, the alkalinity of the environment, and low carbon conditions were major factors influencing calcium carbonate precipitation. High performance liquid chromatography showed that citric acid was a metabolite produced by C. acutatum, and that other organic acids including formic, propionic, α-ketoglutaric, lactic, and succinic acids can be used by this fungus to promote CaCO3 formation. Based on these findings, the mechanism of the biomineralization induced by C. acutatum should be divided into three processes: secreting organic acid to dissolve limestone, utilizing the acid to increase the alkalinity of the microenvironment, and chelating free calcium ions with extracellular polymeric substances or the cell surface to provide a nucleation site. Interestingly, we found that hydroxyapatite rather than calcium carbonate could be produced by this fungus in the presence of phosphate. We also found that the presence of acetic acid could inhibit the transformation of vaterite to calcite. Further, we evaluated whether the proliferation of C. acutatum could influence the deterioration of stone relics. We found that low carbon conditions protected calcium carbonate from dissolution, indicating that the risk of degradation of limestone substrates caused by C. acutatum could be controlled if the fungi were used to consolidate or restore stone monuments. These results suggest that C. acutatum-induced biomineralization may be a useful treatment for deteriorated stone relics.

Li, X., Pan, Y., Hu, S., Cheng, Y., Wang, Y., Wu, K., Zhang, S., Yang, S., 2018. Diversity of phenanthrene and benz[a]anthracene metabolic pathways in white rot fungus Pycnoporus sanguineus 14. International Biodeterioration & Biodegradation 134, 25-30.


Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic compounds. White rot fungi (WRF) have attracted much attention due to their strong capabilities for the initial transformation of PAHs. To better understand the metabolic pathway of PAHS by WRF in the presence of ligninolytic enzymes and cytochrome P450 monooxygenase (P450s), degradation by a high laccase-producing fungus, Pycnoporus sanguineus 14, was examined in detail. This strain with high laccase activity (2516.7 U L−1) exhibited 45.6% biodegradation of phenanthrene (PHE) and 90.1% of benz[a]anthracene (BAA) under in vivo conditions. Gas chromatography–mass spectrometry (GC-MS) was used to identify 2-methylphenol as the product of PHE, and benz[a]anthracene-7,12-dione, 2,3-dihydroxy-3-phenylpropanoic acid and citramalic acid were identified as products of BAA. The results of an in vitro experiment indicated that the strain could

initially transform PHE to 2-dibenzofuranol by intracellular enzymes containing P450s, or 9,10-phenanthrenedione by extracellular laccase, and could initially transform BAA to benz[a]anthracene-7,12-dione via extracellular laccase.

Li, Y.-F., Sun, W., Liu, X.-W., Zhang, D.-W., Wang, Y.-C., Liu, Z.-Y., 2018. Study of the relationship between fractures and highly productive shale gas zones, Longmaxi Formation, Jiaoshiba area in eastern Sichuan. Petroleum Science 15, 498-509.

https://doi.org/10.1007/s12182-018-0249-7

Shale fractures are an important factor controlling shale gas enrichment and high-productivity zones in the Longmaxi Formation, Jiaoshiba area in eastern Sichuan. Drilling results have, however, shown that the shale fracture density does not have a straightforward correlation with shale gas productivity. Based on logging data, drilling and seismic data, the relationship between shale fracture and shale gas accumulation is investigated by integrating the results of experiments and geophysical methods. The following conclusions have been drawn: (1) Tracer diffusion tests indicate that zones of fracture act as favorable channels for shale gas migration and high-angle fractures promote gas accumulation. (2) Based on the result of azimuthal anisotropy prediction, a fracture system with anisotropy strength values between 1 and 1.15 represents a moderate development of high-angle fractures, which is considered to be favorable for shale gas accumulation and high productivity, while fracture systems with anisotropy strength values larger than 1.15 indicate over-development of shale fracture, which may result in the destruction of the shale reservoir preservation conditions.

Li, Y., Nesterenko, P.N., Stanley, R., Paull, B., Macka, M., 2018. High sensitivity deep-UV LED-based z-cell photometric detector for capillary liquid chromatography. Analytica Chimica Acta 1032, 197-202.


A new high sensitivity deep-UV LED photometric detector with a z-type flow cell (45 nL or 180 nL) for miniaturised and portable capillary liquid chromatography (LC) was designed and fabricated to overcome sensitivity limitations due to short pathlength in on-capillary detectors. The new detector has a 10 mm geometric pathlength and uses high intensity light-emitting diodes (LED) as light sources in the deep-UV range (254 nm and 280 nm). No optical reference was necessary due to the low drift in the signal. Stray light was minimized by the use of an adjustable slit with a 0.5 mm pinhole. The direct relationship between absorbance and concentration was obtained using dichromate to evaluate the sensitivity and the linearity range of the detector. Performance of the miniaturised version was compared with that obtained from a commercial benchtop detector for capillary LC under the same conditions using the same optical z-cell. The miniaturised version exhibited a superior performance across all parameters, including 3 times higher effective pathlength, 4 times higher upper limit of detector linearity, and 2–5 times lower stray light levels. An application of the new detector was shown with the detection of l-dopa, l-tyrosine, norfenefrine, phenylephrine and tyramine, separated using capillary LC. The baseline noise level recorded was as low as 3.9 μAU. Further, the detector was applied in a miniaturised capillary LC for the indirect detection of common inorganic anions. In comparison to an on-capillary LED detector applied under similar chromatographic conditions, there was a 50 times higher signal to noise (S/N) ratio.

Li, Y., Zhang, L., Wu, L., Sun, S., Shan, H., Wang, Z., 2018. Purification and enrichment of polycyclic aromatic hydrocarbons in environmental water samples by column clean-up coupled with continuous flow single drop microextraction. Journal of Chromatography A 1567, 81-89.


A novel method for the determination of sixteen polycyclic aromatic hydrocarbons (PAHs) in environmental water samples was developed using column clean-up (CCU) coupled with continuous flow single drop microextraction (CF-SDME) prior to the determination by gas chromatography-mass spectrometry (GC–MS). In this method, purification, extraction and enrichment were carried out in a single step, which reduced the effect of most organic interferents on the determination of target analytes, greatly simplified the operation process and shortened the whole pre-treatment time. The CCU-CF-SDME system was first used, and shortcomings such as long extraction time, instability of suspended microdrop of the traditional SDME system were overcome. The influences of several experimental parameters, including the type and amount of column packing material, the type and volume of extraction solvent, the flow rate of sample solution, extraction temperature, pH and ionic strength of sample solution, on the extraction efficiency were investigated. Under the optimal experimental conditions, the good linearities were obtained in the concentration range of 0.02–10 μg L−1 with correlation coefficients ranging from 0.9912 to 0.9995 for all the analytes. The limits of detection and quantification of the analytes were in the range of 0.0012–0.0101 μg L−1 and 0.0041–0.0336 μg L−1, respectively. The pre-concentration factors in the range of 777–978 for the PAHs were obtained. The proposed method was applied on the analysis of environmental water samples, and the recoveries of target analytes were in the range of 81.8–105.8% with the relative standard deviations ranging from 0.5% to 6.4%. The results showed that the developed method was a simple, quick and feasible method for the determination of PAHs in environmental water samples.

Liao, J., Lu, H., Feng, Q., Zhou, Y., Shi, Q., Peng, P.a., Sheng, G., 2018. Identification of a novel C33 botryococcane and C33 botryococcanone in the Maoming Basin, China. Organic Geochemistry 124, 103-111.


A novel C33 botryococcane in a sedimentary sample from the Maoming Basin in China was found to have a methyl group positioned β to the quaternary carbon C-10 in its structure based on IR, MS and NMR analyses and Lindeman-Adams modelling. This structure is inconsistent with the prediction from the currently accepted botryococcene biosynthetic pathway and different from the skeleton for the C33 botryococcanes suggested in the literature. A C33 botryococcan-24-one with the same carbon skeleton as the C33 botryococcane was also found to co-occur in the sediment sample. The location of the carbonyl group at C-24 is different from that of a previously reported botryococcenone from an Australian collection of race B of Botryococcus braunii where it is positioned at C-15. We propose a biogeochemical pathway to explain the occurrence of this unique skeleton in the Maoming Basin sediment. The biochemical component of the pathway involves electrophilic or nucleophilic attack between two farnesyl diphosphates (FPPs) leading to direct or indirect formation of a C30 botryococcene via a cyclobutane ring intermediate (1′-2-3-2′ cyclisation). A Retro-Prins reaction and subsequent methylation gives rise to C29 and C33 botryococcenes in sequence. The geochemical component involves first in-water-column (photo)-oxidation of the alkene to a C33 botryococcanone and subsequent reduction (hydrogenation) to stabilize the ketone as an alkane.

Liigand, P., Liigand, J., Cuyckens, F., Vreeken, R.J., Kruve, A., 2018. Ionisation efficiencies can be predicted in complicated biological matrices: A proof of concept. Analytica Chimica Acta 1032, 68-74.


The importance of metabolites is assessed based on their abundance. Most of the metabolites are at present identified based on ESI/MS measurements and the relative abundance is assessed from the relative peak areas of these metabolites. Unfortunately, relative intensities can be highly misleading as different compounds ionise with vastly different efficiency in the ESI source and matrix components may cause severe ionisation suppression. In order to reduce this inaccuracy, we propose predicting the ionisation efficiencies of the analytes in seven biological matrices (neat solvent, blood, plasma, urine, cerebrospinal fluid, brain and liver tissue homogenates). We demonstrate, that this approach may lead to an order of magnitude increase in accuracy even in complicated matrices. For the analyses of 10 compounds, mostly drugs, in negative electrospray ionisation mode we reduce the predicted abundance mismatch compared to the actual abundance on average from 660 to 8 times. The ionisation efficiencies were predicted based on i) the charge delocalisation parameter WAPS and ii) the degree of ionisation α, and the prediction model was subsequently validated based on the cross-validation method ‘leave-one-out’.

Lin, D., Wang, J., Yuan, B., Shen, Y., 2017. Review on gas flow and recovery in unconventional porous rocks. Advances in Geo-Energy Research 1, 39-53.


This study summarizes gas flow process in unconventional porous rocks, including the transportation in tight or shale reservoirs and the spontaneous imbibition happened in them. Fluids flow is greatly affected by the pore structure together with the pore size distribution of porous media. The MRI and BET measurement show peaks in pore throat radius ranging from 2 to 20 nm, whereas the diameter for methane and helium are 0.38 and 0.26 nm, respectively. Yet for different types of reservoir, distinct mechanisms should be utilized based on the flow regimes. Besides, experimental measurement techniques for conventional reservoirs are no long accurate enough for most of the unconventional reservoirs. New attempts have been implemented to obtain more valuable data for accurate reservoir prediction. By reviewing large numbers of articles, a clear and comprehensive map on the gas flow and recovery in unconventional reservoirs is made. Factors influencing the gas flow and recovery are investigated in detail for mathematical simulation process. Reservoir conditions and the sweep efficiency play an important role during gas production process. Besides, adsorbed gas contributes a lot to the total gas recovery. The overall investigations suggest that many parameters that influence the gas flow in unconventional porous rocks should be taken into consideration during the evaluation. Among them, permeability, adsorbed gas dynamics, stimulated reservoir volume as well as the unstimulated reservoir volume, and imbibition effect are the most important ones. This study provides valuable data and reasonable exploitations for characterizing gas flow and recovery in unconventional porous rocks.



Significance: Anomalous sulfur isotopic compositions preserved in sedimentary rocks older than ∼2.5 billion years have been widely interpreted as the products of UV photolysis of sulfur dioxide in an anoxic atmosphere and used to track the history of primitive Earth and evolution of early life. In this study, we present strong observational evidence that there is an additional process that produces similar anomalous sulfur isotope signatures. This previously unknown origin not only offers a tool for quantifying the present-day atmospheric sulfur budget and evaluating its influences on climate and public health but also implies that anomalous sulfur isotopic compositions in some of the oldest rocks on Earth might have been produced in a way different from that previously thought.

Abstract: The signature of mass-independent fractionation of quadruple sulfur stable isotopes (S-MIF) in Archean rocks, ice cores, and Martian meteorites provides a unique probe of the oxygen and sulfur cycles in the terrestrial and Martian paleoatmospheres. Its mechanistic origin, however, contains some uncertainties. Even for the modern atmosphere, the primary mechanism responsible for the S-MIF observed in nearly all tropospheric sulfates has not been identified. Here we present high-sensitivity measurements of a fifth sulfur isotope, stratospherically produced radiosulfur, along with all four stable sulfur isotopes in the same sulfate aerosols and a suite of chemical species to define sources and mechanisms on a field observational basis. The five-sulfur-isotope and multiple chemical species analysis approach provides strong evidence that S-MIF signatures in tropospheric sulfates are concomitantly affected by two distinct processes: an altitude-dependent positive 33S anomaly, likely linked to stratospheric SO2 photolysis, and a negative 36S anomaly mainly associated with combustion. Our quadruple stable sulfur isotopic measurements in varying coal samples (formed in the Carboniferous, Permian, and Triassic periods) and in SO2 emitted from combustion display normal 33S and 36S, indicating that the observed negative 36S anomalies originate from a previously unknown S-MIF mechanism during combustion (likely recombination reactions) instead of coal itself. The basic chemical physics of S-MIF in both photolytic and thermal reactions and their interplay, which were not explored together in the past, may be another ingredient for providing deeper understanding of the evolution of Earth’s atmosphere and life’s origin.

Lin, Z., Cai, Z., 2018. Negative ion laser desorption/ionization time-of-flight mass spectrometric analysis of small molecules by using nanostructured substrate as matrices. Mass Spectrometry Reviews 37, 681-696.

https://doi.org/10.1002/mas.21558

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an excellent analytical technique for rapid and sensitive analysis of macromolecules such as polymers and proteins. However, the main drawback of MALDI-TOF MS is its difficulty to detect small molecules with mass below 700 Da because of the intensive interference from MALDI matrix in the low mass region. In recent years there has been considerable interest in developing matrix-free laser desorption/ionization by using nanostructured substrates to substitute the conventional organic matrices, which is often referred as surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). Despite these attractive features, most of the current SALDI-TOF MS for the analysis of small molecules employ positive ion mode, which is subjected to produce multiple alkali metal adducts, and thus increases the complexity of the analysis. Different from the complicated adducts produced in positive ion mode, mass spectra obtained in negative ion mode are featured by deprotonated ion peaks without matrix interference, which simplifies the interpretation of mass spectra and detection of unknown. In this review, we critically survey recent advances in nanostructured substrates for negative ion LDI-TOF MS analysis of small molecules in the last 5 years. Special emphasis is placed on the preparation of the nanostructured substrates and the results achieved in negative ion SALDI-MS. In addition, a variety of promising applications including

environmental, biological, and clinical analysis are introduced. The ionization mechanism of negative ionization is briefly discussed.

Lindgren, A., Hugelius, G., Kuhry, P., 2018. Extensive loss of past permafrost carbon but a net accumulation into present-day soils. Nature 560, 219-222.

https://doi.org/10.1038/s41586-018-0371-0

Atmospheric concentrations of carbon dioxide increased between the Last Glacial Maximum (LGM, around 21,000 years ago) and the preindustrial era. It is thought that the evolution of this atmospheric carbon dioxide (and that of atmospheric methane) during the glacial-to-interglacial transition was influenced by organic carbon that was stored in permafrost during the LGM and then underwent decomposition and release following thaw. It has also been suggested that the rather erratic atmospheric δ13C and ∆14C signals seen during deglaciation could partly be explained by the presence of a large terrestrial inert LGM carbon stock, despite the biosphere being less productive (and therefore storing less carbon). Here we present an empirically derived estimate of the carbon stored in permafrost during the LGM by reconstructing the extent and carbon content of LGM biomes, peatland regions and deep sedimentary deposits. We find that the total estimated soil carbon stock for the LGM northern permafrost region is smaller than the estimated present-day storage (in both permafrost and non-permafrost soils) for the same region. A substantial decrease in the permafrost area from the LGM to the present day has been accompanied by a roughly 400-petagram increase in the total soil carbon stock. This increase in soil carbon suggests that permafrost carbon has made no net contribution to the atmospheric carbon pool since the LGM. However, our results also indicate potential postglacial reductions in the portion of the carbon stock that is trapped in permafrost, of around 1,000 petagrams, supporting earlier studies. We further find that carbon has shifted from being primarily stored in permafrost mineral soils and loess deposits during the LGM, to being roughly equally divided between peatlands, mineral soils and permafrost loess deposits today.

Liu, C.-H., Chu, W., Li, H., Boyd, S.A., Teppen, B.J., Mao, J., Lehmann, J., Zhang, W., 2019. Quantification and characterization of dissolved organic carbon from biochars. Geoderma 335, 161-169.


Dissolved organic carbon (DOC) in biochars is critical to carbon dynamics and contaminant transport in soils. This study aimed to develop a robust and easy method to characterize and quantify the biochar-DOC, using water-, acid-, and base-extractable DOC samples (WEOC, AEOC, and BEOC respectively) from 46 biochars produced from diverse feedstocks and pyrolysis conditions. BEOC concentrations were the highest (2.3–139 mg-C/g-biochar), followed by WEOC (0.5–40 mg-C/g-biochar) and AEOC (0.2–23 mg-C/g-biochar). Fast-pyrolysis biochars generally had higher DOC concentrations than slow-pyrolysis biochars. DOC concentrations in slow-pyrolysis biochars decreased exponentially with increasing pyrolysis temperature from 300 to 600 °C. The solid-state 13C NMR showed that biochar-DOC had abundant small fused-ring aromatics, aliphatic C, and carboxyl C. Biochar-DOC included an acid-precipitated (AP) fraction of higher molecular weight and aromaticity and an acid-soluble (AS) fraction of lower molecular weight and aromaticity. BEOC generally had a greater AP fraction than WEOC and AEOC. Molecular weight, aromaticity and composition of AEOC and BEOC differed from those of more environmentally-relevant WEOC, suggesting that the acid- and base-extraction may not produce the DOC released in real soils. Finally, a quick, easy and robust UV–vis spectrometric method was developed to measure the composition and concentrations of WEOC in diverse biochar samples (R2 = 0.96, n = 46).

Liu, H., Guo, P., Zhan, S., Ma, P., Wei, N., Zhao, J., Qiu, Y., 2018. Experimental investigation into formation/dissociation characteristics of methane hydrate in consolidated sediments with resistance measurement. Fuel 234, 985-995.


Natural gas hydrates (NGHs) are considered as a powerful potential energy resource. In this work, an experimental system containing a digital electrical bridge for resistance measurement was developed to gain an improved understanding of the formation/dissociation characteristics of NGHs in consolidated sediments. Using the apparatus, a dynamic methane hydrate formation method for sandstone cores was developed that can maintain a constant gas flow in the core during the methane hydrate formation process. As opposed to the traditional method that maintains a constant pressure in the core, higher resistance, permeability, and hydrate saturation for the core were obtained following methane hydrate formation equilibrium by using the proposed method. In order to investigate the methane hydrate formation characteristics in sandstone cores, the influences of core permeability, temperature, initial water saturation, and salinity on the resistance and hydrate saturation of two cores were analyzed in detail. The experimental results demonstrate that a relative lower temperature and higher initial water saturation in the core correspond to a higher hydrate saturation and water-to-hydrate conversation ratio. In the process of methane production from continent hydrate, the water output from the core with methane extraction was experimentally measured for the first time. It was found that, owing to the existence of free gas in the core holder, both the core resistance and methane production rate were not changed linearly with time. The methane production amount increased with an increase in initial water saturation, decrease in production pressure, or increase in pore volume in the core. It was demonstrated that water output is not a serious problem in the development of continental natural gas hydrate.

Liu, J., Selby, D., Obermajer, M., Mort, A., 2018. Rhenium–osmium geochronology and oil–source correlation of the Duvernay petroleum system, Western Canada sedimentary basin: Implications for the application of the rhenium–osmium geochronometer to petroleum systems. American Association of Petroleum Geologists Bulletin 102, 1627-1657.

http://archives.datapages.com/data/bulletns/2018/08aug/BLTN17105/bltn17105.html

The Re–Os geochronometer has been applied to many petroleum systems worldwide. However, it is debated if the Re–Os systematics in petroleum actually record the timing of oil generation. Here, we investigate the Re–Os isotope systematics of the Duvernay petroleum system in the Western Canada sedimentary basin, which has been shown to be a relatively simple petroleum system that is associated with oil generated during the Late Cretaceous–early Eocene Laramide orogeny from a single source.

The organic geochemistry of the Duvernay oils (pristane/phytane ratios of ∼1.5, smooth homohopane profile, C29 > C27 > C28 regular sterane distribution, and predominance of diasteranes over regular steranes) strongly suggests the oil source to be that of type I–II marine organic matter of the Upper Devonian Duvernay Formation.

The asphaltene fraction Re–Os isotope data of the Duvernay oil yield an age of 66 ± 31 Ma, which is in excellent agreement with the timing of the main-stage hydrocarbon generation of the Duvernay Formation based on basin models. Further, the similarity between the 187Os/188Os compositions of the Duvernay Formation source rock (0.46–1.48) and the oil (0.55–1.06) at the time of oil generation

supports the hypothesis that the 187Os/188Os composition of an oil is inherited from the source unit at the time of oil generation and therefore shows no, or limited, influence from interaction with basin fluids. This study supports that the Re–Os isotope systematics of an oil can yield the timing of oil generation and be used to trace its source.

Liu, J., Wang, J., Izon, G., Antler, G., Wang, Z., Zhao, J., Egger, M., 2018. Vivianite formation in methane-rich deep-sea sediments from the South China Sea. Biogeosciences Discussions 2018, 1-32.

https://doi.org/10.5194/bg-2018-340

Phosphorus is often invoked as the ultimate limiting nutrient, modulating primary productivity on geological timescales. Consequently, along with nitrogen, phosphorus bioavailability exerts a fundamental control on organic carbon production, linking all the biogeochemical cycles across the Earth system. Unlike nitrogen that can be microbially fixed from an essentially infinite atmospheric reservoir, phosphorus availability is dictated by the interplay between its sources and sinks. While authigenic apatite formation has received considerable attention as the dominant sedimentary phosphorus sink, the quantitative importance of reduced iron-phosphate minerals, such as vivianite, has only recently been acknowledged and their importance remains under-explored. Combining microscopic and spectroscopic analyses of handpicked mineral aggregates with sediment geochemical profiles we characterize the distribution and mineralogy of iron-phosphate minerals present in methane-rich sediments recovered from the northern South China Sea. Here, we demonstrate that vivianite authigenesis is pervasive in the iron oxide-rich sediments below the sulfate-methane transition zone (SMTZ). We hypothesize that the downward migration of the SMTZ concentrated vivianite formation below the current SMTZ. Our observations support recent findings from non-steady state post-glacial coastal sedimentary successions, suggesting that iron reduction below the SMTZ, probably driven by iron-mediated anaerobic oxidation of methane (Fe-AOM), is coupled to phosphorus cycling on a much greater spatial scale than previously assumed. Calculations reveal that vivianite acts as an important burial phase for both iron and phosphorus below the SMTZ, sequestering approximately half of the total reactive iron pool. By extension, sedimentary vivianite formation could serve as a mineralogical marker of Fe-AOM, signalling a low-sulfate availability against methanogenic and ferruginous backdrop. Given that similar conditions were likely present throughout vast swaths of Earth history, it is possible that Fe-AOM may have modulated phosphorus and methane availability on the early Earth.

Liu, M., Gadikota, G., 2018. Probing the influence of thermally induced structural changes on the microstructural evolution in shale using multiscale X-ray scattering measurements. Energy & Fuels 32, 8193-8201.


Various pathways to accelerate the recovery of hydrocarbons from unconventional subsurface environments have been proposed, including the use of high-temperature fluids. However, the influence of temperature on the structural and microstructural changes in complex subsurface materials characterized by compositional and morphological heterogeneity are not very well understood. In this study, in operando ultrasmall angle, small angle, and wide-angle X-ray scattering (USAXS/SAXS/WAXS) measurements were performed to link the structural and morphological changes in shale when heated from 30 to 1150 °C. The structural changes observed from the wide-angle X-ray scattering measurements were complemented by the changes in the porosity, particle size, and surface morphology. Overall, the combined USAXS/SAXS measurements showed enhanced smoothness in the pore–solid interface on heating. The dehydroxylation of illite and calcination of

calcium carbonate were noted prior to the formation of denser and sintered silicate and alumino-silicate phases such as Mg2SiO4 (forsterite), Fe0.3Mg0.7(SiO3) (enstatite), and Al2.35Si0.64O4.82 (mullite).

Liu, Y., Gang, W., Chen, G., Sun, J., Jiang, C., 2018. Geochemical characteristics of aromatic hydrocarbons of Chang7 source rocks from the Yanchi-Dingbian area, Ordos Basin. Acta Sedimentologica Sinica 86, 818-828.


Based on the GC-MS analytical data of 16 samples of Chang7 source rocks from 13 wells in the Yanchi-Dingbian area, Ordos Basin, the geochemical characteristics of aromatic hydrocarbons of source rocks, the origins and sedimentary environments were investigated in detail, and the validity of maturity parameters of aromatic hydrocarbon biomarkers were discussed. It is shown that the source rocks in the study area are characterized by high abundance of bicyclic and tricyclic aromatic hydrocarbons, low abundance of tetracyclic and pentacyclic aromatic hydrocarbons, relatively high abundance of fluorene, relatively high abundance of 1,2,5-TMN and 1,2,5,6-TeMN in some samples, a certain content of terrigenous biomarkers such as retene, perylene, chrysene and pyrene. All these results indicated the source rocks of Chang7 Formation were mainly developed in slightly oxidizing-reducing shore-shallow lacustrine environment. Besides, the terrestrial higher plants input had certain contribution in the formation of source rocks. The maturity parameters of alkyl naphthalene, alkyl phenanthrene and alkyl dibenzothiophene from aromatic hydrocarbons suggested that the thermal evolution stage of source rocks reached the maturity stage. Although the equivalent vitrinite reflectance calculated by different series of aromatic compounds had some differences, it could qualitatively reflect the stage of thermal evolution of source rocks.

Liu, Y., Yao, Y., Liu, D., Zheng, S., Sun, G., Chang, Y., 2018. Shale pore size classification: An NMR fluid typing method. Marine and Petroleum Geology 96, 591-601.


Shale reservoir is characterized by complex pore networks, within which there are various pore fluids including unrecoverable fluid, capillary bound fluid and movable fluid. Although considerable literature has investigated the pore structure of gas shale using different laboratory testing techniques, few papers have provided a quantified model to distinguish different types of fluids (corresponding to different pore types) in shale. In this study, seven shale core plugs from the Sichuan Basin were measured in a series of NMR experiments under full brine-saturated, centrifugal and heat-treated conditions to analyze the pore structure information and pore fluid transport during the processes of centrifuging and heating. For a typical T2 spectrum of 100% brine-saturated shale, the movable fluid T2 cutoff (T2C1) and unrecoverable fluid cutoff (T2C2) were derived from NMR centrifugal and heat-treated experiments to distinguish the unrecoverable fluid (T2 < T2C2), capillary bound fluid (T2C2 <T2< T2C1) and movable fluid (T2 > T2C1). Our results show that for the investigated shales, the T2C2 ranges from 0.09 ms to 0.36 ms, and T2C1 has a wide range from 0.45 ms to 2.98 ms. The surface relaxivities range from 0.00426 μm/ms to 0.02822 μm/ms, and the shales having high silicate mineral contents commonly have low surface relaxivities. A conceptional model based on the dual T2 cutoff method was constructed to illustrate the full-scale pore size distribution: unrecoverable fluid pores, capillary bound fluid pores and movable fluid pores. This study provides a new method of pore fluid typing and full-scale pore size distribution classification for shales.

Liu, Z., Liu, D., Cai, Y., Pan, Z., 2018. The impacts of flow velocity on permeability and porosity of coals by core flooding and nuclear magnetic resonance: Implications for coalbed methane production. Journal of Petroleum Science and Engineering 171, 938-950.


The fluid flow velocity has a significant effect on the coalbed methane (CBM) production by influencing the porosity and permeability of coals during the drainage process. In this work, the fluid velocity sensitivity experiments combined with the nuclear magnetic resonance (NMR) technology were performed to investigate the impacts of various flow velocities on permeability and porosity. The results show that the permeability of different rank coals has various characteristics with the increase of flow velocity. For low rank coals, the permeability always increases first then decreases with the increase of flow velocity. However, the permeability gradually decreases with the increase of flow velocity for medium and high rank coals. For the same rank coals, the higher initial permeability is, the more severe permeability damage is. Additionally, the porosity variation reflected by NMR T2 spectrum indicates that T2 between 10 ms and 200 ms is the main reduction space of seepage paths. The influence of flow velocity on permeability is mainly due to the blockage of fluid seepage space by coal fines. Moreover, the effects of dewatering rate on CBM production were further discussed combined with field production wells. The dropping rate of working fluid level at the single-phase water stage plays an important role on the production of coal fines and gas production, especially at the late production stage. Decreasing dewatering rate at the two-phase (water and gas) stage can improve the CBM production effectively. To improve the effect of flow velocity on petrophysical properties of CBM reservoir, the dewatering rate of CBM wells should be slow and stable. Therefore, this study could be conducive to CBM production or mining safety.

Lopes, A.M., Ferreira Filho, E.X., Moreira, L.R.S., 2018. An update on enzymatic cocktails for lignocellulose breakdown. Journal of Applied Microbiology 125, 632-645.

https://doi.org/10.1111/jam.13923

Alternative energy sources have received increasing attention in recent years. The possibility of adding value to agricultural wastes, by producing biofuels and other products with economic value from lignocellulosic biomass by enzymatic hydrolysis, has been widely explored. Lignocellulosic biomass, as well as being an abundant residue, is a complex recalcitrant structure that requires a consortium of enzymes for its complete degradation. Pools of enzymes with different specificities acting together usually produce an increase in hydrolysis yield. Enzymatic cocktails have been widely studied due to their potential industrial application for the bioconversion of lignocellulosic biomass. This review presents an overview of enzymes required to degrade the plant cell wall, paying particular attention to the latest advances in enzymatic cocktail production and the main results obtained with cocktails used to degrade a variety of types of biomass, as well as some future perspectives within this field.

López, D., Sepúlveda-Mardones, M., Ruiz-Tagle, N., Sossa, K., Uggetti, E., Vidal, G., 2019. Potential methane production and molecular characterization of bacterial and archaeal communities in a horizontal subsurface flow constructed wetland under cold and warm seasons. Science of The Total Environment 648, 1042-1051.


Organic matter removal in a horizontal subsurface flow constructed wetland (HSSF) treating wastewater is associated with the presence of bacteria and archaea. These organisms perform anaerobic microbial processes such as methanogenesis, which can lead to methane emissions. The aim of this study was to evaluate methane production and characterize the bacterial and archaeal communities found in HSSFs treating secondary urban wastewater during cold and warm seasons. The pilot system used in this study corresponds to four HSSFs, two planted with Phragmites australis (HSSF−Phr) and two planted with Schoenoplectus californicus (HSSF−Sch), the monitoring was carried out for 1335 days. Removal efficiencies for organic matter (biological and chemical oxygen demand) and total and volatile suspended solids were evaluated in each HSSF. Moreover, biomass from each HSSF was sampled during warm and cold season, and methane productions determined by Specific Methanogenic Activity assays(maximum) (SMAm). In the same samples, the quantification and identification of bacteria and archaea were performed. The results showed that the degradation of organic matter (53–67% BOD5 and 51–62% COD) and suspended solids (85–93%) was not influenced by seasonal conditions or plant species. Potential methane production from HSSF-Sch was between 20 and 51% higher than from HSSF-Phr. Moreover, potential methane production during warm season was 3.4–42% higher than during cold season. The quantification of microorganisms in HSSFs, determined greater development of bacteria (38%) and archaea (50–57%) during the warm season. In addition, the species Schoenoplectus californicus has a larger number of bacteria (4–48%) and archaea (34–43%) than Phragmites australis. The identification of microorganisms evidenced the sequences associated with bacteria belong mainly to Firmicutes (42%), Proteobacteria (33%) and Bacteroidetes (25%). The archaea were represented primarily by Methanosarcinales, specifically Methanosaeta (75%) and Methanosarcina (16%). The community structure of the methanogenic archaea in HSSFs did not change throughout the seasons or plant species.

Losey, R.J., Nomokonova, T., Gusev, A.V., Bachura, O.P., Fedorova, N.V., Kosintsev, P.A., Sablin, M.V., 2018. Dogs were domesticated in the Arctic: Culling practices and dog sledding at Ust’-Polui. Journal of Anthropological Archaeology 51, 113-126.


Domestication has particular salience in archaeology, and numerous recent theoretical papers describe this process as a set of evolutionary, ongoing, social, and material relationships between humans and select other species. In contrast, analytical papers on the domestication of dogs nearly always involve a search for their origins as marked by changes in genes and morphologies. This article explores this contrast through the examination of dog remains from the Iron Age Ust’-Polui site in the western Siberian Arctic. Many of the numerous dogs represented at this site were killed and probably consumed when young, likely as part of sacrifices. Others at the site were intentionally buried. Ust’-Polui also contains abundant evidence of advanced dog sledding, including probable harness parts and portions of several complex sleds. Sacrificing and otherwise killing dogs is a domestication practice, as these activities are a form of selective breeding. Domestication of dogs at Ust’-Polui and elsewhere is more than selective breeding, as it is enabled and dependent upon specific landscapes, built things, and other species. At Ust’-Polui these at a minimum included a rich local environment, sleds and harness swivels, and freshwater fish, all of which intertwined in making the particular domestic relationships at the site possible.

Louca, S., Shih, P.M., Pennell, M.W., Fischer, W.W., Parfrey, L.W., Doebeli, M., 2018. Bacterial diversification through geological time. Nature Ecology & Evolution 2, 1458-1467.

https://doi.org/10.1038/s41559-018-0625-0

Numerous studies have estimated plant and animal diversification dynamics; however, no comparable rigorous estimates exist for bacteria—the most ancient and widespread form of life on Earth. Here, we analyse phylogenies comprising up to 448,112 bacterial lineages to reconstruct global bacterial diversification dynamics. To handle such large phylogenies, we developed methods based on the statistical properties of infinitely large trees. We further analysed sequencing data from 60 environmental studies to determine the fraction of extant bacterial diversity missing from the phylogenies—a crucial parameter for estimating speciation and extinction rates. We estimate that there are about 1.4–1.9 million extant bacterial lineages when lineages are defined by 99% similarity in the 16S ribosomal RNA gene, and that bacterial diversity has been continuously increasing over the past 1 billion years (Gyr). Recent bacterial extinction rates are estimated at 0.03–0.05 per lineage per million years (lineage–1 Myr–1), and are only slightly below estimated recent bacterial speciation rates. Most bacterial lineages ever to have inhabited this planet are estimated to be extinct. Our findings disprove the notion that bacteria are unlikely to go extinct, and provide a valuable perspective on the evolutionary history of a domain of life with a sparse and cryptic fossil record.

Lozano-Sánchez, J., Borrás-Linares, I., Sass-Kiss, A., Segura-Carretero, A., 2018. Chapter 13 - Chromatographic technique: High-performance liquid chromatography (HPLC), in: Sun, D.-W. (Ed.), Modern Techniques for Food Authentication (Second Edition). Academic Press, pp. 459-526.

http://www.sciencedirect.com/science/article/pii/B978012814264600013X

High-performance liquid chromatography (HPLC) is a separation technique, which can be applied to analyze compounds of different samples. Depending on the nature, chemical structure, and molecular weight of the analytes, it is possible to select the type of HPLC. In this sense, different kinds of HPLC have emerged to allow qualitative and quantitative information regarding individual components of the sample under study. The knowledge of these kinds of components is the basis to detect manipulations and fraudulence for profiteering, evading the law set in the interest of food authenticity. The aim of this chapter is to describe HPLC principles and different methods as a tool for the qualitative and/or quantitative identification of the components present in a specific sample which could be use as fingerprints in the authentication process.

Lu, G., Wang, J., Wei, C., Song, Y., Yan, G., Zhang, J., Chen, G., 2018. Pore fractal model applicability and fractal characteristics of seepage and adsorption pores in middle rank tectonic deformed coals from the Huaibei coal field. Journal of Petroleum Science and Engineering 171, 808-817.


Middle rank tectonic deformed coal samples were screened from the Xutuan and Qinan coal mine in the Huaibei coal field, Anhui Province, North China. Based on mercury injection capillary pressure analysis and nitrogen sorption experiments using the Brunuaer-Emmett-Teller analysis, pore structure characteristics and applicability of the Sierpinski, Menger, Thermodynamics, and Frenkel-Halsey-Hill models for seepage and adsorption pore description were analyzed, as well as the fractal characteristics of the two types of pores. Several conclusions have been achieved. 1) The Sierpinski model can characterize the heterogeneity of seepage pores in tectonic deformed coals, and the thermodynamic model can be used for referencing and comparative analysis. The Frenkel-Halsey-Hill model can be used to describe the heterogeneity of adsorption pores, and the Sierpinski model can be a supplement. However, the Menger model is not suitable for characterizing the pore heterogeneity of coal because its fractal dimension exceeds three, and the standard deviation is larger than the others. 2) The fractal dimension of adsorption pores increases while seepage pores decreases, with the enhancement of tectonic deformation. The heterogeneity of adsorption pores in the cataclastic,

schistose and scaly coals are weaker than that of seepage pores (Ds2<Ds1), the heterogeneity of the adsorption pores in wrinkle coal is similar to that of seepage pores (Ds2≈Ds1), whereas the adsorption pores' heterogeneity in mylonitic coal is stronger than that of seepage pores (Ds2>Ds1).

Lu, H., Zhang, H., Chingin, K., Xiong, J., Fang, X., Chen, H., 2018. Ambient mass spectrometry for food science and industry. TrAC Trends in Analytical Chemistry 107, 99-115.


Ambient mass spectrometry (AMS) allows direct molecular characterization of various raw food samples with minimal or no sample pretreatment. Because of the excellent sensitivity and specificity of analysis, AMS has been increasingly applied in food science and industry. In virtually, any type of food samples including solid, liquid, viscous, and bulk food samples could be directly analyzed using mass spectrometry powered by versatile ambient ionization techniques. Moreover, mass spectrometry imaging (MSI) offers a unique opportunity to explore the spatial-chemical information from numerous food samples. Herein, the principle of AMS, typical instrumental setup, and applications in different type of food samples are systematically reviewed, the advantages and shortages of AMS for food analysis are mentioned, and the impact and challenge of AMS on food science are briefly discussed.

Lucas, S.G., 2018. Permian-Triassic charophytes: Distribution, biostratigraphy and biotic events. Journal of Earth Science 29, 778-793.

https://doi.org/10.1007/s12583-018-0786-4

Permian charophytes are known from the Ukraine, Russia, Kazakhstan, Germany, Saudi Arabia, China, the USA, Brazil, Paraguay and India. Most of these records are of Middle- Late Permian Age and are the basis of local biostratigraphic zonation in southern Russia and China. Development of a robust Permian charophyte biostratigraphy will require a more extensive record. Triassic charophytes are known from Germany, Sweden, Poland, Slovenia, Bulgaria, the Ukraine, Russia, Morocco, Congo, the USA, Argentina, Kazakhstan and China. This encompasses records from all Triassic stages and has been the basis of detailed biostratigraphic zonation in southern Russia-Kazakhstan-eastern Europe. Permian and Triassic charophyte biostratigraphy at the level of genus does not provide detailed correlations beyond local or regional schemes. Nevertheless, it does identify some important evolutionary datums that constrain the timing of important biotic events in the Permian-Triassic evolutionary history of the Charophyta, including: (1) Early Permian extinction of the Palaeocharaceae; (2) Late Permian extinction of the “Trochiliscales” (Moellerinales); (3) Carboniferous origin of the paraphyletic Porocharaceae, soon followed during the Permian by the origin of the multicellular basal plate; and (4) an important generic turnover of charophytes across the Triassic-Jurassic boundary, though there are insufficient data to identify this as a mass extinction.



Bacterial endophytes (BEs) are non-pathogenic residents of healthy plant tissues that can confer benefits to plants. Many Bacterial endophytes have been shown to contribute to plant growth and health, alleviation of plant stress and to in-planta contaminant-degradation. This study examined the

endophytic bacterial communities of plants growing abundantly in a heavily hydrocarbon contaminated site, and compared them to those found in the same species at a non-contaminated. We used culture- dependent and independent methods to characterize the community structure, hydrocarbon degrading capabilities, and plant growth promoting traits of cultivable endophytes isolated from Achillea millefolium, Solidago Canadensis, and Daucus carota plants from these two sites. Culture- dependent and independent analyses revealed class Gammaproteobacteria predominated in all the plants regardless of the presence of petroleum hydrocarbon, with Pantoea spp. as largely dominant. It was interesting to note a >50% taxonomic overlap (genus level) of 16s rRNA high throughput amplicon sequences with cultivable endophytes. PERMANOVA analysis of TRFLP fragments revealed significant structural differences between endophytic bacterial communities from hydrocarbon-contaminated and non-contaminated soils—however, there was no marked difference in their functional capabilities. Pantoea spp. demonstrated plant beneficial characteristics, such as P solubilization, indole-3-acetic acid production and presence of 1-aminocyclopropane-1-carboxylate deaminase. Our findings reveal that functional capabilities of bacterial isolates being examined were not influenced by the presence of contamination; and that the stem endosphere supports ubiquitous BEs that were consistent throughout plant hosts and sites.

Luo, F., Feng, F., Zhao, B., Tian, B., Yang, X., Zhou, H., Li, X., 2018. Research progress of micro-electro-mechanical systems micro gas chromatography columns. Chinese Journal of Chromatography 36, 707-715.

http://www.chrom-china.com/EN/abstract/abstract14525.shtml

The gas chromatography (GC) column is a key component of the gas chromatographic system, which is mainly used for the separation of mixed gas components. Compared with the traditional GC column, the micro GC column based on micro-electro-mechanical systems (MEMS) technology has the advantages of lighter weight, smaller volume, lower power consumption, and faster analysis. Furthermore, it can be integrated into a portable instrument, such as a miniaturized GC. The research progress of micro GC columns based on MEMS technology is summarized in this paper. First, the theoretical basis of the MEMS micro GC column is stated. Then, the layout and inner structure of the MEMS micro GC column, the stationary-phase support, and the preparation of the stationary phase are summarized. Finally, trends in the development of MEMS micro GC columns are discussed.

Luo, Q., Gong, L., Qu, Y., Zhang, K., Zhang, G., Wang, S., 2018. The tight oil potential of the Lucaogou Formation from the southern Junggar Basin, China. Fuel 234, 858-871.


The mudstones of the Lucaogou Formation are the most important and organic-rich sediments and tight oil exploration target in the northwestern China. The organic and stable isotope geochemistry, and organic petrology were used to evaluate their sedimentary environments and hydrocarbon generative potential. The Lucaogou mudstones contain abundant organic matter, S2, hydrogen index (HI) and extractable organic matter (EOM), whereas S1 values are low. The δ13C values of EOM are very light and display a negative correlation with HI. Rock pyrolysis data imply a low maturity (0.6–0.7 %Ro equivalent) of the Lucaogou Formation, consistent with aliphatic and aromatic hydrocarbon ratios. The biological sources are predominately algae and bacteria, with less contribution of higher plants in the Lucaogou Formation as indicated by δ13CEOM, biomarkers and maceral composition. The Lucaogou mudstones contain low ratios of C31R/C30 hopane, C29/C30 hopane and C22/C21 tricyclic terpane, and high C24/C23 tricyclic terpane value, which are consistent with their depositional environments (i.e., lacustrine). The abundant β-carotane, gammacerane and hop-17(21)-enes indicate

a hypersaline and anoxic environment. The studied samples are predominantly oil-prone with a dominant type I and II1 kerogen. High contents of total organic carbon (TOC), S2, HI, EOM, saturated and aromatic hydrocarbons indicate that the Lucaogou Formation hold significant exploration potential of tight oil.

Lv, M., Du, M., 2018. A review: microbiologically influenced corrosion and the effect of cathodic polarization on typical bacteria. Reviews in Environmental Science and Bio/Technology 17, 431-446.

https://doi.org/10.1007/s11157-018-9473-2

Microbiologically influenced corrosion is a serious type of corrosion as approximately 20% of the total economic losses. Sulfate reducing bacteria and Iron oxidizing bacteria are one of the typical representatives of the anaerobic and aerobic bacteria, which are ubiquitous in natural environments and corrode steel structures. Cathodic polarization has been recognized as an effective method for preventing steels from microbial corrosion. Although cathodic polarization method has been widely studied, the specific properties of cathodic current that influences the bacterial removal and inactivation remained largely unclear. This review is to show the main effects of Sulfate reducing bacteria and Iron oxidizing bacteria on metal decay as well as the inhibition mechanism of cathodic polarization in the study of bio-corrosion.


https://doi.org/10.1038/s41598-018-30153-x

Pore characterization in shales is challenging owing to the wide range of pore sizes and types present. Haynesville-Bossier shale (USA) was sampled as a typical clay-bearing siliceous, organic-rich, gas-mature shale and characterized over pore diameters ranging 2 nm to 3000 nm. Three advanced imaging techniques were utilized correlatively, including the application of Xe+ plasma focused ion beam scanning electron microscopy (plasma FIB or PFIB), complemented by the Ga+ FIB method which is now frequently used to characterise porosity and organic/inorganic phases, together with transmission electron microscope tomography of the nano-scale pores (voxel size 0.6 nm; resolution 1–2 nm). The three pore-size scales each contribute differently to the pore network. Those <10 nm (greatest number), 10 nm to 100 nm (best-connected hence controls transport properties), and >100 nm (greatest total volume hence determines fluid storativity). Four distinct pore types were found: intra-organic, organic-mineral interface, inter-mineral and intra-mineral pores were recognized, with characteristic geometries. The whole pore network comprises a globally-connected system between phyllosilicate mineral grains (diameter: 6–50 nm), and locally-clustered connected pores within porous organic matter (diameter: 200–800 nm). Integrated predictions of pore geometry, connectivity, and roles in controlling petrophysical properties were verified through experimental permeability measurements.

Maeda, A., Fujita, K., Horikawa, K., Suzuki, A., Ohno, Y., Kawahata, H., 2018. Calibration between temperature and Mg/Ca and oxygen isotope ratios in high-magnesium calcite tests of asexually reproduced juveniles of large benthic foraminifers. Marine Micropaleontology 143, 63-69.


Mg/Ca ratios and oxygen isotope ratios (δ18O) in biogenic high-magnesium calcite tests precipitated by reef-dwelling large benthic foraminifers can be used as paleotemperature proxies because they

correlated well with the temperature of seawater. However, it is still unclear whether there is an interspecies difference in temperature correlation among several perforate and imperforate species. We used four species of large benthic foraminifers to perform culture experiments at controlled temperatures (21–31 °C). Neorotalia calcar, Baculogypsina sphaerulata, and Calcarina gaudichaudii were selected as the perforate species, whereas Amphisorus kudakajimensis was chosen as the imperforate species. The data obtained by analyses suggest linear relations between Mg/Ca and temperature except at 31 °C, and also in the case of A. kudakajimensis except at 29 °C, which is likely caused by thermal stress resulting in metabolic anomaly in the foraminifers. Furthermore, A. kudakajimensis (imperforate species) had a different Mg/Ca–temperature equation form those of perforate species. The combined Mg/Ca–temperature and δ18O–temperature equations are yielded using the least square method as follows: Mg/Ca = 2.73 T + 74.7 for three perforate species, which is applicable to a temperature range between 21 °C to 30 °C. The temperature relation of δ18O is different even among perforate species. We observed that the δ18O values were closer to the equilibrium of pure calcite than those of high-magnesium calcite. The δ18O–temperature (T) equations are yielded using the least square method as follows: T = 15.1–6.17 (δ18Oc − δ18Osw) for C. gaudichaudii, T = 17.7–5.14 (δ18Oc − δ18Osw) for N. calcar, and T = 16.1–5.10 (δ18Oc – δ18Osw) for B. sphaerulata. A species-specific calibration is necessary for the relation between δ18O and temperature. As long as the optimum temperature range is the same, foraminifers belonging to the Calcarinidae show the same Mg/Ca–temperature relationship.

Mahan, B., Moynier, F., Siebert, J., Gueguen, B., Agranier, A., Pringle, E.A., Bollard, J., Connelly, J.N., Bizzarro, M., 2018. Volatile element evolution of chondrules through time. Proceedings of the National Academy of Sciences 115, 8547-8552.


Significance: We present time-anchored elemental abundance data for some of the Solar System’s first solids by tracking Pb−Pb dated chondrule compositions. Volatile element contents generally rise, while redox conditions (based on chondrule Mn/Na ratios) decline beginning ∼1 My after Solar System formation (∼4,567 Ma). These results reflect a continued rise in volatile element contents and their fugacities during chondrule recycling, and early water influx to the inner Solar System followed by its express removal. These observations support the early formation of Mars under oxidizing condition and Earth’s protracted growth under more reducing conditions in an environment increasing in volatile contents with time, while also calling into question the coupling of water and volatile elements during Solar System evolution.

Abstract: Chondrites and their main components, chondrules, are our guides into the evolution of the Solar System. Investigating the history of chondrules, including their volatile element history and the prevailing conditions of their formation, has implications not only for the understanding of chondrule formation and evolution but for that of larger bodies such as the terrestrial planets. Here we have determined the bulk chemical composition—rare earth, refractory, main group, and volatile element contents—of a suite of chondrules previously dated using the Pb−Pb system. The volatile element contents of chondrules increase with time from ∼1 My after Solar System formation, likely the result of mixing with a volatile-enriched component during chondrule recycling. Variations in the Mn/Na ratios signify changes in redox conditions over time, suggestive of decoupled oxygen and volatile element fugacities, and indicating a decrease in oxygen fugacity and a relative increase in the fugacities of in-fluxing volatiles with time. Within the context of terrestrial planet formation via pebble accretion, these observations corroborate the early formation of Mars under relatively oxidizing conditions and the protracted growth of Earth under more reducing conditions, and further suggest that water and volatile elements in the inner Solar System may not have arrived pairwise.

Makita, H., 2018. Iron-oxidizing bacteria in marine environments: recent progresses and future directions. World Journal of Microbiology and Biotechnology 34, Article 110.

https://doi.org/10.1007/s11274-018-2491-y

Iron-oxidizing bacteria (FeOB) refers to a group of bacteria with the ability to exchange and accumulate divalent iron dissolved in water as trivalent iron inside and outside the bacterial cell. Most FeOB belong the largest bacterial phylum, Proteobacteria. Within this phylum, FeOB with varying physiology with regards to their response to oxygen (obligate aerobes, facultative and obligate anaerobes) and pH optimum for proliferation (neutrophiles, moderate and extreme acidophiles) can be found. Although FeOB have been reported from a wide variety of environments, most of them have not been isolated and their biochemical characteristics remain largely unknown. This is especially true for those living in the marine realm, where the properties of FeOB was not known until the isolation of the Zetaproteobacteria Mariprofundus ferrooxydans, first reported in 2007. Since the proposal of Zetaproteobacteria by Emerson et al., the detection and isolation of those microorganisms from the marine environment has greatly escalated. Furthermore, FeOB have also recently been reported from works on ocean drilling and metal corrosion. This review aims to summarize the current state of phylogenetic and physiological diversity in marine FeOB, the significance of their roles in their environments (on both global and local scales), as well as their growing importance and applications in the industry.

Mandić, J., Tronczyński, J., Kušpilić, G., 2018. Polycyclic aromatic hydrocarbons in surface sediments of the mid-Adriatic and along the Croatian coast: Levels, distributions and sources. Environmental Pollution 242, 519-527.


This study provides contamination levels, distributions and source apportionment of PAHs in surface sediments in the mid-Adriatic and along the Croatian coast. Median summed concentrations of parent and alkyl-PAHs are circa 10 times lower in the off-shore transect stations of the mid-Adriatic (22.3 and 18.2 μg.kg−1 d.w.) than the ranges determined at the coastal stations, including those of Kaštela bay (227–331 and 11.7–197 μg.kg−1 d.w., respectively). The highest levels, circa 20 times higher, were found in Šibenik bay (median 6603 and 3051 μg.kg−1). The overall range of PAH concentrations spans more than 2000 times between the lowest and the highest contamination level. The geographical distributions reflect the presence of strong gradients at local and regional scales. A major factor influencing sedimentary PAH distributions at local scale appears to be the distance from their known continental and coastal upstream emission sites (urban, industrial, harbour …), whereas at regional scale, this distribution depends more on the routes of entry of PAHs into the study area. Two combustion and one petroleum model source profiles of PAHs were determined by alternative least square analysis. Benzo[b+j]fluoranthenes and fluoranthene/pyrene are compounds characterizing two pyrogenic sources respectively, while signatures of alkyl-substituted homologues (phenanthrenes/anthracenes, fluranthenes/pyrenes, chrysenes and dibenzothiophenes) delineate a petrogenic source profile. The quantitative apportionment of source contributions shows significant geographical differences, with a dominant petrogenic source found along the mid-Adriatic transect (approximately 74%) and in Kaštela bay (61%). In the coastal sediments about a fifty-fifty contamination mix is assigned to a petrogenic/pyrogenic source of PAHs (47% and 53% respectively), whereas in Šibenik bay a strong predominance is apportioned to the combustion compounds (81%).



This paper compares pore size distributions in different sedimentary facies shales for similar maturity in typical areas, China. Pore size distributions were analyzed using low-pressure gas adsorption, mercury intrusion capillary pressure, and field-emission scanning electron microscopy techniques. Results showed that pore volume and surface area of shales clearly covary with sedimentary facies, total organic carbon (TOC) contents, clay minerals, maturity, and kerogen type. Influenced by the compaction and clay minerals, the immature terrestrial Jurassic Yanan shales exhibited the highest pore volume and surface area, which are much higher than those of overmature transitional Permian Shanxi and marine Longmaxi shales. The pore volume of shales mainly consists of meso- and macropores, whereas micro- and mesopores comprise most of the surface area. For similar immature shales, pore size distributions are mainly influenced by the degree of compaction. For similar overmature shales, pore size distributions are mainly influenced by kerogen type and TOC content.

Marques, J.M., Etiope, G., Neves, M.O., Carreira, P.M., Rocha, C., Vance, S.D., Christensen, L., Miller, A.Z., Suzuki, S., 2018. Linking serpentinization, hyperalkaline mineral waters and abiotic methane production in continental peridotites: an integrated hydrogeological-bio-geochemical model from the Cabeço de Vide CH4-rich aquifer (Portugal). Applied Geochemistry 96, 287-301.


Continental active serpentinization of ultramafic rocks is today recognized as a key process triggering a sequence of phenomena involving the passage from inorganic, to organic and metabolic reactions. These may have a role in the origin of life, and may explain the occurrence of abiotic hydrocarbons on Earth and other planets. Production of hyperalkaline waters and abiotic methane (CH4) are two critical steps in this sequence. They were described independently by specific hydrogeological and geochemical models. Here, we update and combine these models into a unified scheme using and integrating geological, hydrogeological, hydrogeochemical, gas-geochemical and microbial analyses acquired from 2002 to 2014 in the Cabeço de Vide (CdV) study site, Portugal. The hyperalkaline (pH > 10.5), Na-Cl/Ca-OH mineral water of CdV evolve from groundwater-peridotite interaction (serpentinization) generating hydrogen (H2), which, according to multiple theoretical, laboratory and field evidence, likely reacted with CO2 within metal- (catalyst) rich rocks, abiotically producing CH4 (up to 1.2 mg/L; -24.4‰  < δ13C-CH4 < -14.0‰ and -285‰  < δ2H-CH4 < -218‰ ). The hyperalkaline water hosts hydrogen oxidizing bacteria “Serpentinomonas”, which may explain the paucity of H2 observed in the dissolved gas. The CdV gas-rich mineral waters ascend along a fault at the boundary of the peridotite intrusion. Temporal changes of pH and CH4 concentration result from episodic mixing with shallower Mg-HCO3-type waters. Soil-gas analyses show that methane migrates to the surface along the fault, also independently from the water emergences, consistently with non-aqueous abiotic CH4 production. Our integrated model is generally compatible with observations from other gas-bearing continental serpentinization sites.

Martins, C., Brandão, T., Almeida, A., Rocha, S.M., 2018. Unveiling the lager beer volatile terpenic compounds. Food Research International 114, 199-207.


Beer volatile terpenic compounds arise from a network of variables, namely from plant raw-materials metabolism, yeast metabolism, among others, and may suffer modifications during brewing. In order to increase the molecular understanding of beer volatile terpenic compounds, this work intends to perform a comprehensive characterization of these molecules on lager beer, using an advanced multidimensional chromatographic methodology. This research comprises the most detailed screening of lager beer terpenic compounds through the putative identification of 94 mono and sesquiterpenic compounds, distributed over 6 chemical families: alcohols, aldehydes, esters, ketones, hydrocarbons, and oxides. The terpenic profiles allowed the beer terpen-typing according to samples' category clustering: macro and micro-brewer beers. This study adds further insight to the lager beer terpenic volatile composition, and could be applied in large-scale studies in different contexts, namely for understanding the distinctive beer styles or for beer typing.

März, C., Riedinger, N., Sena, C., Kasten, S., 2018. Phosphorus dynamics around the sulphate-methane transition in continental margin sediments: Authigenic apatite and Fe(II) phosphates. Marine Geology 404, 84-96.


The formation of authigenic phosphate minerals in marine sediments is an important process for the burial and long-term storage of the bio-essential nutrient phosphorus (P). In this context, we report the composition of pore waters, bulk sediments, and the speciation of P in four sediment cores recovered on the continental margins off the Amazon, Rio de la Plata and Zambezi rivers. Here, pronounced sulphate-methane transitions (SMTs) occur between 4.5 and 6.5 m sediment depth where sulphate is consumed by the anaerobic oxidation of methane and free hydrogen sulphide builds up in the pore waters. This leads to the reductive dissolution of primary Fe (oxyhydr)oxides (FeOx) by hydrogen sulphide, and the subsequent liberation of FeOx-adsorbed phosphate into pore waters at the SMT. The released phosphate builds up to significant concentrations, making it available for the precipitation of authigenic minerals within and below the SMT. Using a sequential P extraction, we find consistently high contributions of carbonate fluorapatite (CFA) to the total P pool within the SMT, where it likely precipitates due to high local phosphate concentrations, high alkalinity and abundant dissolved Ca in the pore waters. PHREEQC calculations confirm these results, with highest saturation states with respect to authigenic apatite calculated at all SMTs. CFA authigenesis, however, is insufficient to completely consume pore water phosphate, leading to diffusive loss of phosphate from the SMT. While the upward decrease in phosphate above the SMT is relatively gentle, the significantly steeper phosphate gradient into underlying sediments suggests the formation of another authigenic mineral phase. Sequential P extraction and PHREEQC results clearly show that the dominant authigenic phase below the SMT is not CFA. Instead, geochemical conditions below the sulphidic zone at all four sites are favourable for the precipitation of Fe(II) phosphate minerals (e.g., vivianite). These conditions are summarized as the absence of sulphate and free hydrogen sulphide, but the presence of Fe2+ and phosphate in pore waters, and low calcium carbonate contents in the sediment. While we did not directly detect or quantify Fe(II) phosphate minerals, Fe-bound P clearly increases in the sediments below the sulphidic zones at all studied sites, and this is where highest pore water saturation states with respect to vivianite are calculated with PHREEQC. In addition, geochemical inverse models performed in PHREEQC show that vivianite formation is an important geochemical process controlling the observed patterns of dissolved P and Fe, pH and redox potential of the pore waters analysed below the SMT. We therefore argue that Fe(II) phosphate minerals are formed in these ocean margin sediments on a large scale, and pore water and sediment data indicate that this Fe-bound P largely originates from FeOx-adsorbed phosphate liberated within the sulphidic SMT. This study suggests that under specific but not unusual depositional conditions, SMTs are hotspots for biogeochemical P cycling in marginal marine sediments worldwide, with CFA

precipitating within the SMT, and Fe(II) phosphates forming below it. It also adds to the growing evidence that Fe(II) phosphates may contribute significantly to the long-term burial of reactive P phases in Fe-rich, methanic marine sediments, and thus act as a previously underestimated sedimentary P sink.



Samples of the low-maturity New Albany Shale (Middle and Upper Devonian to Lower Mississippian) and Mowry Shale (Late Cretaceous), both containing kerogen Type II, and samples of Wilcox Coal (Eocene), containing kerogen Type III, were heated to 60, 100, and 200 °C at hydrostatic ambient pressure, 100, or 300 MPa for 6 or 12 months in sealed glass and gold cells to investigate temperature and pressure effects on porosity and thermal maturity. In addition, lithostatic experiments were conducted in a hydraulic press at 100 MPa and 100 °C over a period of 6 months. Porosimetric characteristics of samples before and after experiments were investigated by using low-pressure gas adsorption and scanning electron microscope (SEM).

An increase from ambient temperature to 200 °C caused increases in random vitrinite reflectance (Ro) for all samples, with Mowry Shale showing the largest increase from 0.57% to 0.65% and Wilcox Coal showing the smallest increase from 0.39% to 0.41%. For Mowry Shale and New Albany Shale, specific surface areas did not change in any notable way with an increase in temperature; specific surface area values for Mowry Shale ranged from 2.0 to 3.2 m2/g, and for New Albany Shale from 13.7 to 15.6 m2/g. Differences in Barrett-Joyner-Halenda (BJH) specific mesopore volumes and average mesopore size for the shales were also small to negligible. Considering the values of the original samples, we propose that these small differences are related to internal inhomogeneity of samples rather than to any temperature effect. Temperature-related changes in Wilcox Coal were more distinct. Specifically, there was a marked decrease in BET surface area, from 4.9 m2/g at 60 °C to 1.5 m2/g at 200 °C, and a decrease in both BJH mesopore volume and average mesopore size. The Wilcox Coal sample had large micropore surface areas (110–148 m2/g) compared to both shales, which had micropore surface areas below 10 m2/g. While Wilcox Coal showed a drop in micropore volume between 60 °C and 200 °C, no distinct or regular changes in micropore volume with temperature were documented for the other two samples.

A sustained hydrostatic pressure increase from ambient to 300 MPa for 6 to 12 months resulted in insignificant changes in vitrinite reflectance values. Small differences in Brunauer-Emmett-Teller (BET) specific surface areas, micropore surface area, and volume may be related to internal sample heterogeneity rather than pressure treatment. Similar to the temperature effect, the Wilcox Coal sample experienced more pronounced changes compared to the shales. SEM observations on shales did not reveal porosity-related changes between the original and treated samples. No marked changes were documented for lithostatic pressure conditions at 100 MPa and 100 °C. We conclude that elevated isotropic hydrostatic or lithostatic pressure is unable to significantly affect the pore structure and pore-size distribution of shales, but it can make some modifications in the micropore and mesopore pore characteristics of low-rank coal.

Masterson, A., Alperin, M.J., Berelson, W.M., Johnston, D.T., 2018. Interpreting multiple sulfur isotope signals in modern anoxic sediments using a full diagenetic model (California-Mexico margin: Alfonso Basin). American Journal of Science 318, 459-490.


Recent studies targeting the metabolic, physiological, and biochemical controls of sulfur isotope fractionation in microbial systems have drawn linkages between results from culture experiments and the sulfur isotope signatures observed in natural environments. Several of those studies have used newer techniques to explore the minor isotope (33S and 36S) variability in those systems, and also have attempted to place them in an ecophysiological context. Sparingly few have incorporated this newfound understanding of minor isotope behavior into natural systems (sediment pore waters, water columns) and none of them have refined existing isotope-dependent reaction-transport models to explicitly include 33S. In this study, we construct a three-isotope (32S, 33S, and 34S) reaction-transport model of pore water sulfate for a well-characterized sedimentary system within the California-Mexico Margin (Alfonso Basin). An additional goal is placing recent laboratory culture work into a natural, physical context. The model first reproduces the measured bulk geochemical characteristics of the pore water profiles of [SO4

2−], [CH4], dissolved inorganic carbon ([DIC]), and [Ca2+]—and predicts bulk (non-isotope-specific but depth-dependent) rates of sulfate reduction. Next, the model uses those depth-dependent bulk rates, in combination with empirically calibrated fractionation factors, to explain the minor isotope characteristics (δ34S and Δ33S values) of the 0 to 40 cm pore water SO4

2−. The down core, isotopic evolution of pore water sulfate requires a large fractionation associated with sulfate reduction (34εSR = 70 ± 5‰) that appears to be independent of bulk rate, but in line with low temperature thermodynamic predictions. The minor isotope characteristics (33λSR ∼ 0.5130) are also independent of rate and fall within the range expected from microbial calibrations, but differ from minor isotope predictions of thermodynamic equilibrium. The high value of 34εSR raises key questions in relating the physiological state of marine microorganisms relative to their laboratory counterparts, as well as point toward exceedingly low metabolic rates in natural marine sediments.

Mazur, D.M., Zenkevich, I.G., Artaev, V.B., Polyakova, O.V., Lebedev, A.T., 2018. Regression algorithm for calculating second-dimension retention indices in comprehensive two-dimensional gas chromatography. Journal of Chromatography A 1569, 178-185.


Gas chromatography-mass spectrometry (GC–MS) is one of the most accurate, well developed, and reliable analytical tools for the analysis of volatile and semivolatile compounds. The GC–MS data have been extensively improved by enhancing the separation capacity via comprehensive two-dimensional gas chromatography (GC × GC). The reliability of the identification of the analytes in GC × GC–MS can be notably improved by applying the second-dimension retention index (2I) as additional analytical parameter along with the commonly used first dimension retention index (1I) and mass spectrum. A novel approach for calculating second-dimension retention indices (2I) for semivolatile organic compounds is proposed. It is noteworthy that the standards used in calculations are the same compounds recommended as internal standards by US EPA 8270 Method for analysis of semivolatile organic compounds. The new algorithm takes into account the analyte retention time and its retention temperature at the secondary column, (2tR) and (2TR), respectively. The experimental data collected with different primary oven temperature ramp rates and carrier gas flow rates have shown that the calculated by the proposed approach 2I values remain the same for each evaluated compound, drifting in a very narrow range. The proposed approach was tested using 100 organic compounds from various chemical classes including alkanes, phenols, nitrobenzenes, chlorinated hydrocarbons, anilines, polycyclic aromatic hydrocarbons (PAHs), phthalates, etc. The important advantage of the proposed 2I values for compounds of the same chemical origin (reference standards and analytes) involves applicability of well-known Lee’s indices for non-polar phases. Therefore, the proposed approach can be used in targeted and non-targeted analysis of a wide range of organic compounds.

The reduced version of the second dimension retention indices provides a valuable mapping of the homologues series of organic compounds, making their detection and identification easy and reliable.

Mazzoli, R., Giuffrida, M.G., Pessione, E., 2018. Back to the past—forever young: cutting-edge biochemical and microbiological tools for cultural heritage conservation. Applied Microbiology and Biotechnology 102, 6815-6825.

https://doi.org/10.1007/s00253-018-9121-3

Ancient documents and milestones of human history such as manuscripts and textiles are fragile and during aging undergo chemical, physical, and biological deterioration. Among the different causes of damage, also human intervention plays a role since some restoration strategies proved to be transient and/or they generated further damage. Outdoor monuments undergo deterioration since they are exposed to pollution, weathering, microbial attack (giving rise to undesired pigmentation, discoloration or true dissolution, corrosion, and overall decay), as well as man-made damage (i.e., graffiti). This review article reports the best-fitting strategies used to restore wall paintings, outdoor monuments, textiles, and paper documents to their ancient beauty by employing “soft” biobased approaches such as viable bacteria or suitable enzymes.



The need to understand the biodegradation of oil and chemical dispersants in Arctic marine environments is increasing alongside growth in oil exploration and transport in the region. We chemically quantified biodegradation and abiotic losses of crude oil and Corexit 9500, when present separately, in incubations of Arctic seawater and identified microorganisms potentially involved in biodegradation of these substrates based on shifts in bacterial community structure (16S rRNA genes) and abundance of biodegradation genes (GeoChip 5.0 microarray). Incubations were performed over 28-day time courses using surface seawater collected from near-shore and offshore locations in the Chukchi Sea. Within 28 days, the indigenous microbial community biodegraded 36% (k = 0.010 day-

1) and 41% (k = 0.014 day-1) of oil and biodegraded 77% and 33% (k = 0.015 day-1) of the Corexit 9500 component dioctyl sodium sulfosuccinate (DOSS) in respective near-shore and offshore incubations. Non-ionic surfactants (Span 80, Tween 80, and Tween 85) present in Corexit 9500 were non-detectable by 28 days due to a combination of abiotic losses and biodegradation. Microorganisms utilized oil and Corexit 9500 as growth substrates during the incubation, with the Corexit 9500 stimulating more extensive growth than oil within 28 days. Taxa known to include oil-degrading bacteria (e.g. Oleispira, Polaribacter, and Colwellia) and some oil biodegradation genes (e.g. alkB, nagG, and pchCF) increased in relative abundance in response to both oil and Corexit 9500. These results increase our understanding of oil and dispersant biodegradation in the Arctic and suggest that some bacteria may be capable of biodegrading both oil and Corexit 9500. ¬

McKay, G., Korak, J.A., Rosario-Ortiz, F.L., 2018. Temperature dependence of dissolved organic matter fluorescence. Environmental Science & Technology 52, 9022-9032.


The temperature dependence of organic matter fluorescence apparent quantum yields (Φ f) was measured for a diverse set of organic matter isolates (i.e., marine aquatic, microbial aquatic, terrestrial

aquatic, and soil) in aqueous solution and for whole water samples to determine apparent activation energies (Ea) for radiationless decay processes of the excited singlet state. Ea was calculated from temperature dependent Φf data obtained by steady-state methods using a simplified photophysical model and the Arrhenius equation. All aquatic-derived isolates, all whole water samples, and one soil-derived fulvic acid isolate exhibited temperature dependent Φf values, with Ea ranging from 5.4 to 8.4 kJ mol–1 at an excitation wavelength of 350 nm. Conversely, soil humic acid isolates exhibited little or no temperature dependence in Φf. Ea varied with excitation wavelength in most cases, typically exhibiting a decrease between 350 and 500 nm. The narrow range of Ea values observed for these samples when compared to literature Ea values for model fluorophores (∼5–30 kJ mol–1) points to a similar photophysical mechanism for singlet excited states nonradiative inactivation across organic matter isolates of diverse source and character. In addition, this approach to temperature dependent fluorescence analysis provides a fundamental, physical basis, in contrast to existing empirical relationships, for correcting online fluorescence sensors for temperature effects.



Lipid biomarkers preserved in ancient rocks have the potential to reveal much about ancient ecosystems. However, establishing that the compounds of interest are syngenetic has proven to be an analytically challenging task. Traditional biomarker analyses rely on extraction of large quantities of powdered rock, making the association of molecules with sedimentary fabrics difficult, if not impossible. As an alternative approach, here we show that monoclonal antibodies that bind specifically to geolipids can be used as molecular probes for in situ detection and localization of such compounds. Monoclonal antibodies that bind to squalene and cross-react with the biomarker squalane were evaluated for labeling sediment-associated hydrocarbons. The anti-squalene antibodies were shown by dot immunoblotting with composed standards to cross-react also with other isoprenoids, such as phytol and its diagenetic products, suggesting reactivity towards acyclic isoprenoids. Then, the anti-squalene antibodies were shown to react with naturally occurring crude oils and, via an immunofluorescence-labeling approach, to bind to isolated organic-rich laminae in rocks from the Eocene Green River Formation known to contain squalane among other linear isoprenoids. These results suggest that squalane, or structurally similar organic biomarkers that cross-react with the antibodies, are confined to discrete organo-sedimentary fabrics within those rocks, providing evidence for their syngeneity. Depending on the specificity and sensitivity of the antibody/geolipid pair, an in situ antibody detection approach may be useful for establishing biomarker syngeneity in older rocks.

Medjor, W.O., Akpoveta, V.O., Egharevba, F., 2018. Kinetics and physicochemical studies of surfactant enhanced remediation of hydrocarbons contaminated groundwater. Egyptian Journal of Petroleum 27, 169-176.


Kinetics and physicochemical studies of surfactant enhanced remediation of hydrocarbons contaminated groundwater were investigated for efficiency and effectiveness. 10% pollution was simulated in the laboratory by contaminating groundwater samples with crude oil, automatic gasoline oil (diesel) and domestic purpose kerosene (DPK) in replicates of five. Physicochemical properties of the hydrocarbons contaminated groundwater samples and a control sample were investigated before

and after treatments. Total petroleum (TPH) hydrocarbon as target contaminant was monitored periodically to assess the extent of the remediation process. TPH was determined by molecular spectrophotometry technique. Other physicochemical parameters such as pH, turbidity, alkalinity, dissolved oygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), condutiivity, ammonia, nitrate, phosphate, salinity, total dissolved solids (TDS), total suspended solids (TSS) and total solids (TS) were obtained using standard methods while heavy metals levels were determined by atomic absorption spectrophotometry. Different kinetics models were tested to determine the appropriate kinetics model. The pseudo-first order kinetics is established with rate constant as 1.80×104; 1.78×104; 1.53×104mg−1Lh−1 for crude oil, diesel and kerosene respectively at 30°C. At the end of the remediation after 6h there was 89.11%; 93.21%; 87.76% reduction in TPH as crude oil, diesel and kerosene for the treated samples in that order. The application of surfactant enhanced remediation using sodium dodecyl sulphate is found be very efficient, effective and rapid in reducing total petroleum hydrocarbon as crude oil, kerosene and diesel as target contaminants. There is the need for post-treatments after remediation for most of the physicochemical parameters are impaired and do not meet the Guideline and Standards for Environmental Pollution Control in Nigeria set by Federal Ministry of Environment and World Health Organization for drinking water and agricultural uses in order to make them fit for these purposes.

Mei, M., Bissada, K.K., Malloy, T.B., Darnell, L.M., Liu, Z., 2018. Origin of condensates and natural gases in the Almond Formation reservoirs in southwestern Wyoming, USA. Organic Geochemistry 124, 164-179.


Condensates and natural gases are significant resources that frequently occur together in many petroleum systems. Unraveling their origins is crucial for effective petroleum exploration and exploitation. This is often a challenge because light crudes are volatile, deficient in biomarkers, and commonly altered. The origin of condensates and natural gases in the Upper-Cretaceous Almond Formation in southwestern Wyoming was unraveled through use of improved analytical and interpretative geochemical approaches constrained by regional geologic perspectives and basin modeling. Here, an improved GC–MS/MS method allowed simultaneous determination of saturate and aromatic biomarkers, diamondoids, and organo-sulfur compounds in the whole crudes. Furthermore, basin-specific calibration of diamondoid-based thermal maturity parameters, through correlation of measured indices for diamondoids in rock extracts versus measured reflectance of vitrinite from the same rocks, allowed reliable interpretation of maturity of the most likely source rocks. Modified interpretation schemes for C7-hydrocarbon distributions, and compositions of C1-C30 alkanes, aromatic and organosulfur compounds, and δ13C1-C5 together indicated that the condensate and natural gas from each well are likely co-generated and thermogenic products from non-marine source rocks, although methane is partially biogenic. The bulk thermogenic petroleum are too mature to have originated in the rocks adjacent to the producing reservoirs. The geochemical, geologic, and modeling interpretations collectively indicate that the condensates and associated natural gases were most likely generated, expelled, and migrated from the downdip, highly mature, near-shore/transitional humic source rocks of the Almond Formation/Mesaverde Group in the Washakie Basin and Great Divide Basin at >1.3% Ro and ∼30 Ma.

Mekik, F., 2018. Do proxies agree? δ18O, δ13C and Mg/Ca from tests of Neogloboquadrina dutertrei in the eastern equatorial Pacific. Geochimica et Cosmochimica Acta 236, 260-282.


We present new δ18Oand δ13C data from Neogloboquadrina dutertrei tests picked from 30 core tops in the eastern equatorial Pacific (EEP) combined with a compilation of published stable isotope and Mg/Ca data. We studied the effects of foraminifer test size on stable isotope data using four size fractions of N. dutertrei: <250 µm, 250–350 µm, 400–500 µm, and 500–600 µm. We find that δ18O decreases and δ13C increases with increasing test size in the smaller size fractions. For tests > 500 µm these trends plateau for δ13C and are reversed for δ18O. Statistically, the most robust relationships between δ18O and temperature, and between δ13C and apparent oxygen utilization, occur in size fractions <350 µm. We studied the effects of dissolution on all three proxies using the Globorotalia menardii Fragmentation Index (MFI). We find no effect of dissolution on shell stable isotope geochemistry in core tops from the EEP. Shell dissolution has an observable effect on the Mg/Ca of N. dutertrei shells, but this effect is difficult to quantify. We used stable isotope shell geochemistry to reconstruct N. dutertrei habitat depths in the EEP which reflect oceanographic current patterns. Habitat depths estimated with the Mg/Ca paleo-thermometer do not agree with those calculated from δ18O data. This is mostly due to the gross disparity between estimates made with various Mg/Ca-temperature calibration equations, many of which are not calibrated with habitat depth temperatures. The difference of means ranges between 5 and 7 °C for temperature estimates made with two independent Mg/Ca –temperature calibrations for the Pacific. We do not find a discernible effect of test size in the disparity of temperature estimates with Mg/Ca; however calibrating Mg/Ca-temperature equations with δ18O-based habitat depth temperatures yields more robust temperature estimates.

Menefee, A.H., Giammar, D.E., Ellis, B.R., 2018. Permanent CO2 trapping through localized and chemical gradient-driven basalt carbonation. Environmental Science & Technology 52, 8954-8964.


Recent laboratory and field studies have demonstrated that basalt formations may present one of the most secure repositories for anthropogenic CO2 emissions through carbon mineralization. In this work, a series of high-temperature, high-pressure core flooding experiments was conducted to investigate how transport limitations, reservoir temperature, and brine chemistry impact carbonation reactions following injection of CO2-rich aqueous fluids into fractured basalts. At 100 °C and 6.3 mM [NaHCO3], representative of typical reservoir conditions, carbonate precipitates were highly localized on reactive mineral grains contributing key divalent cations. Geochemical gradients promoted localized reaction fronts of secondary precipitates that were consistent with 2D reactive transport model predictions. Increasing [NaHCO3] to 640 mM dramatically enhanced carbonation in diffusion-limited zones, but an associated increase in clays filling advection-controlled flow paths could ultimately obstruct flow and limit sequestration capacity under such conditions. Carbonate and clay precipitation were further enhanced at 150 °C, reducing the pre-reaction fracture volume by 48% compared to 35% at 100 °C. Higher temperature also produced more carbonate-driven fracture bridging, which generally increased with diffusion distance into dead-end fractures. In combination, the results are consistent with field tests indicating that mineralization will predominate in buffered diffusion-limited zones adjacent to bulk flow paths and that alkaline reservoirs with strong geothermal gradients will enhance the extent of carbon trapping.

Meneghin, E., Volpato, A., Cupellini, L., Bolzonello, L., Jurinovich, S., Mascoli, V., Carbonera, D., Mennucci, B., Collini, E., 2018. Coherence in carotenoid-to-chlorophyll energy transfer. Nature Communications 9, Article 3160.

https://doi.org/10.1038/s41467-018-05596-5

The subtle details of the mechanism of energy flow from carotenoids to chlorophylls in biological light-harvesting complexes are still not fully understood, especially in the ultrafast regime. Here we focus on the antenna complex peridinin–chlorophyll a–protein (PCP), known for its remarkable efficiency of excitation energy transfer from carotenoids—peridinins—to chlorophylls. PCP solutions are studied by means of 2D electronic spectroscopy in different experimental conditions. Together with a global kinetic analysis and multiscale quantum chemical calculations, these data allow us to comprehensively address the contribution of the potential pathways of energy flow in PCP. These data support dominant energy transfer from peridinin S2 to chlorophyll Qy state via an ultrafast coherent mechanism. The coherent superposition of the two states is functional to drive population to the final acceptor state, adding an important piece of information in the quest for connections between coherent phenomena and biological functions.

Meng, Y., Li, Z., 2018. Experimental comparisons of gas adsorption, sorption induced strain, diffusivity and permeability for low and high rank coals. Fuel 234, 914-923.


Because of coal pore structure, the adsorption and diffusion behaviors are quite different for low and high rank coals. Differences of gas adsorption-diffusion and adsorption deformation of low and high rank coal and its permeability evolution were carried out in isothermal adsorption experiment and desorption-seepage testing system. The law of adsorption and adsorption induced strain, diffusion of low and high rank coal and its influence on the coal permeability were revealed. It turns out that, the methane adsorption-diffusion and adsorption induced-strain of low and high rank coal increase with the increase of the adsorption equilibrium pressure. Because of the control of pore structure, the diffusion property of low rank coal sample is higher than that of high rank coal sample. And the strain perpendicular to the bedding plane is higher than that parallel to the bedding plane. Sorption-induced strain of high rank coal is higher than that of low rank coal, which is related to the amount of gas adsorption in coal. The Langmuir volumetric strain is about twice as high as that of the low rank coal. The law of gas adsorption deformation of coal can be described by a Langmuir isotherm adsorption equation. The influence of methane adsorption-induced swelling strain on the permeability of high rank coal is higher than that of low rank coal. At a constant effective stress, the permeability of low rank coal is higher than that of high rank coal, and with the increases of adsorption equilibrium pressure, the permeability decline by a negative exponential function of different rank coals; the rate of permeability reduction of high rank coal is higher than that of low rank coal.

Mi, Z., Wang, F., Yang, Y., Wang, F., Hu, T., Tian, H., 2018. Evaluation of the potentiality and suitability for CO2 geological storage in the Junggar Basin, northwestern China. International Journal of Greenhouse Gas Control 78, 62-72.


CO2 geological storage is one of the most important methods for reducing the emissions of anthropogenic greenhouse gases into the atmosphere. Junggar Basin is an important energy base in China, with high CO2 emissions and geological storage potential. The evaluation of the suitability for CO2 geological storage is the basis for screening CO2 geological storage sites, and a scientific and effective evaluation method is key. Using the Junggar Basin as the study site, an indicator system consisting of 3 indicator layers and 27 indicators was constructed. By combining the analytic hierarchy process and fuzzy comprehensive evaluation method, the geological suitability for CO2 geological storage in 44 secondary tectonic units in the Junggar Basin was evaluated. The evaluation

results provide a scientific basis for site selection and project construction for CO2 geological storage in the Junggar Basin.

Miller, S.R., Mueller, P.A., Meert, J.G., Kamenov, G.D., Pivarunas, A.F., Sinha, A.K., Pandit, M.K., 2018. Detrital zircons reveal evidence of Hadean crust in the Singhbhum Craton, India. The Journal of Geology 126, 541-552.

https://www.journals.uchicago.edu/doi/abs/10.1086/698844

The Singhbhum craton is one of five Archean cratons constituting the Indian subcontinent. It consists of four major lithotectonic units with broadly defined ages from Eoarchean to Neoarchean: the Older Metamorphic Group (3.7–3.2 Ga), Older Metamorphic Tonalite Gneisses (3.8–3.1 Ga), Singhbhum Granite (3.5–3.0 Ga), and Iron Ore Group (3.51–2.55 Ga). In this study, 270 zircons were separated from modern sediment of the Baitarani River, which is wholly contained within the craton. Zircons were analyzed with laser ablation ICP-MS for their U-Pb systematics; >50% were less than 5% discordant. Three primary age groupings account for ∼98% of analyses: 3.62–3.55 Ga (5%), 3.50–3.22 Ga (87%), and 3.10–3.06 Ga (6%). The preponderance of 3.50–3.22 Ga zircons is consistent with the local basement that includes a 3.47 Ga tonalite gneiss enclave within a 3.35–3.30 Ga outcrop of the Singhbhum Granite near Keonjhar. Lu-Hf systematics of zircons yielded 67% with positive initial εHf scattered above and below the mantle growth curve and 33% with negative initial εHf, indicating contributions from both depleted mantle and older crustal sources. Single-stage model ages range from 4.29 to 3.10 Ga. Of note is a single zircon with a 207Pb/206Pb age of 4015±9 Ma (1.3% discordant), which is the first Hadean zircon documented from any of the Indian cratons. This grain yielded an initial εHf of −5.30, which indicates an episode of Hadean felsic crust formation in the Singhbhum craton comparable to that proposed for the Jack Hills of the Yilgarn craton (Australia).

Millet, D.B., Alwe, H.D., Chen, X., Deventer, M.J., Griffis, T.J., Holzinger, R., Bertman, S.B., Rickly, P.S., Stevens, P.S., Léonardis, T., Locoge, N., Dusanter, S., Tyndall, G.S., Alvarez, S.L., Erickson, M.H., Flynn, J.H., 2018. Bidirectional ecosystem–atmosphere fluxes of volatile organic compounds across the mass spectrum: How many matter? ACS Earth and Space Chemistry 2, 764-777.


Terrestrial ecosystems are simultaneously the largest source and a major sink of volatile organic compounds (VOCs) to the global atmosphere, and these two-way fluxes are an important source of uncertainty in current models. Here, we apply high-resolution mass spectrometry (proton transfer reaction-quadrupole interface time-of-flight; PTR-QiTOF) to measure ecosystem–atmosphere VOC fluxes across the entire detected mass range (m/z 0–335) over a mixed temperate forest and use the results to test how well a state-of-science chemical transport model (GEOS-Chem CTM) is able to represent the observed reactive carbon exchange. We show that ambient humidity fluctuations can give rise to spurious VOC fluxes with PTR-based techniques and present a method to screen for such effects. After doing so, 377 of the 636 detected ions exhibited detectable gross fluxes during the study, implying a large number of species with active ecosystem–atmosphere exchange. We introduce the reactivity flux as a measure of how Earth–atmosphere fluxes influence ambient OH reactivity and show that the upward total VOC (∑VOC) carbon and reactivity fluxes are carried by a far smaller number of species than the downward fluxes. The model underpredicts the ∑VOC carbon and reactivity fluxes by 40–60% on average. However, the observed net fluxes are dominated (90% on a carbon basis, 95% on a reactivity basis) by known VOCs explicitly included in the CTM. As a result, the largest CTM uncertainties in simulating VOC carbon and reactivity exchange for this environment are associated with known rather than unrepresented species. This conclusion pertains to

the set of species detectable by PTR-TOF techniques, which likely represents the majority in terms of carbon mass and OH reactivity, but not necessarily in terms of aerosol formation potential. In the case of oxygenated VOCs, the model severely underpredicts the gross fluxes and the net exchange. Here, unrepresented VOCs play a larger role, accounting for ∼30% of the carbon flux and ∼50% of the reactivity flux. The resulting CTM biases, however, are still smaller than those that arise from uncertainties for known and represented compounds.

Mloszewska, A.M., Cole, D.B., Planavsky, N.J., Kappler, A., Whitford, D.S., Owttrim, G.W., Konhauser, K.O., 2018. UV radiation limited the expansion of cyanobacteria in early marine photic environments. Nature Communications 9, Article 3088.

https://doi.org/10.1038/s41467-018-05520-x

Prior to atmospheric oxygenation, ecosystems were exposed to higher UV radiation fluxes relative to modern surface environments. Iron–silica mineral coatings have been evoked as effective UV radiation shields in early terrestrial settings. Here we test whether similar protection applied to planktonic cyanobacteria within the Archean water column. Based on experiments done under Archean seawater conditions, we report that Fe(III)–Si-rich precipitates absorb up to 70% of incoming UV-C radiation, with a reduction of <20% in photosynthetically active radiation flux. However, we demonstrate that even short periods of UV-C irradiation in the presence of Fe(III)–Si precipitates resulted in high mortality rates, and suggest that these effects would have persisted throughout much of the photic zone. Our findings imply that despite the shielding properties of Fe(III)–Si-rich precipitates in the early water column, UV radiation would continue to limit cyanobacterial expansion and likely had a greater effect on Archean ecosystem structure before the formation of an ozone layer.


https://doi.org/10.1038/s41396-018-0153-6

Unraveling the relative importance of ecological processes regulating microbial community structure is a central goal in microbial ecology. Here, we used high-throughput sequencing to examine the relative contribution of selective and neutral processes in the assembly of abundant and rare subcommunities from three subtropical bays of China. We found that abundant and rare bacterial taxa were distinctly different in diversity, despite the similar biogeographic patterns and strong distance-decay relationships, but the dispersal of rare bacterial taxa was more limited than that of abundant taxa. Furthermore, the environmental (selective processes) and spatial (neutral processes) factors seemed to govern the assembly and biogeography of abundant and rare bacterial subcommunities, although both factors explained only a small fraction of variation within the rare subcommunity. More importantly, variation partitioning (based on adjusted R2 in redundancy analysis) showed that spatial factors exhibited a slightly greater influence on both abundant and rare subcommunities compared to environmental selection; however, the abundant subcommunity had a much stronger response to spatial factors (17.3% of pure variance was explained) than that shown by the rare bacteria (3.5%). These results demonstrate that environmental selection and neutral processes explained the similar biogeographic patterns of abundant and rare subcommunities, but a large proportion of unexplained variation in the rare taxa (91.1%) implies that more complex assembly mechanisms may exist to shape the rare bacterial assemblages in the three subtropical bays.

Moe, W.M., Reynolds, S.J., Griffin, M.A., McReynolds, J.B., 2018. Bioremediation strategies aimed at stimulating chlorinated solvent dehalogenation can lead to microbially-mediated toluene biogenesis. Environmental Science & Technology 52, 9311-9319.


In situ bioremediation practices that include subsurface addition of fermentable electron donors to stimulate reductive dechlorination by anaerobic bacteria have become widely employed to combat chlorinated solvent contamination in groundwater. At a contaminated site located near Baton Rouge, Louisiana (USA), toluene was transiently observed in groundwater at concentrations that sometimes far exceeded the US drinking water maximum contaminant level (MCL) of 1 mg/L after a fermentable substrate (agricultural feed grade cane molasses) was injected into the subsurface with the intent of providing electron donors for reductive dechlorination. Here, we present data that demonstrate that indigenous microorganisms can biologically produce toluene by converting phenylacetic acid, phenylalanine, phenyllactate, and phenylpyruvate to toluene. When grown in defined medium with phenylacetic acid at concentrations ≤350 mg/L, the molar ratio between toluene accumulated and phenylacetic acid supplied was highly correlated (R2 ≥ 0.96) with a toluene yield exceeding 0.9:1. Experiments conducted using 13C labeled compounds (phenylacetic acid-2-13C and l-phenylalanine-3-13C) resulted in production of toluene-α-13C, confirming that toluene was synthesized from these precursors by two independently developed enrichment cultures. Results presented here suggest that monitoring of aromatic hydrocarbons is warranted during enhanced bioremediation activities where electron donors are introduced to stimulate anaerobic biotransformation of chlorinated solvents.

Mohamed, N.S., El Nady, M.M., Sharaf, L.M., 2018. Evaluation of possible source rocks and extracts characteristics from Safir-1x well, North Western Desert, Egypt. Petroleum Science and Technology 36, 1235-1241.

https://doi.org/10.1080/10916466.2018.1465974

The pyrolysis and vitrinite reflectance estimations for fifteen shale rock tests and additionally, geochemical burial history, and gas chromatography – mass spectrometry parameters were talked about to explore the hydrocarbon generation and maturation level and time, type of hydrocarbon produced of rock units of Safir-1x well. The results assign that the Bahariya Formation is poor to great source rock to create oil and gas, with a lower thermal maturation degree than the Khatatba and Alam El Bueib formation. Alam El Bueib is viewed as good to excellent source rock for oil and gas age, having marginally high level of thermal maturation at oil window at around 40 million years. Khatatba formation achieved the oil and gas generation window at about 80 and 50 million years separately and considered excellent source rock.

The molecular gas chromatography and mass spectrometry parameters demonstrated that the extracts of source rocks reflected that the Bahariya and Alam El Bueib extracts have a mixed sources formed under transitional conditions at low grad of thermal maturation. Khatatba source rock extracts originated from marine sources formed under reducing conditions at high grade of maturation.

Mohtar, R.H., Shafiezadeh, H., Blake, J., Daher, B., 2019. Economic, social, and environmental evaluation of energy development in the Eagle Ford shale play. Science of The Total Environment 646, 1601-1614.


This research investigates the relation between water, energy, and transportation systems, using the growing hydraulic fracturing activity in the Eagle Ford shale play region of southwest Texas in which the local water systems and road infrastructure were not designed for the frequent transport of water into the production site and of produced gas and oil from the site as are often required for hydraulic fracturing. The research: 1) quantifies the interconnections between water, energy, and transportation systems specific to the Eagle Ford shale region; 2) identifies and quantifies the economic, social, and environmental indicators to evaluate scenarios of oil and gas production; and 3) develops a framework for analysis of the economic, societal, and long term sustainability of the sectors and 4) an assessment tool (WET Tool) that estimates several economic indicators: oil and natural gas production, direct and indirect tax revenues, and average wages for each scenario facilitates the holistic assessment of oil and gas production scenarios and their associated trade-offs between them. Additionally, the Tool evaluates these social and environmental indices, (water demand, emissions, water tanker traffic, accidents, road deterioration, and expected average employment times). Scale of production is derived from the price of oil and gas; government revenues from production fluctuations in relation to rise and fall of the oil and gas market prices. While the economic benefits are straightforward, the social costs of shale development (water consumption, carbon emissions, and transportation/infrastructure factors), are difficult to quantify. The tool quantifies and assesses potential scenario outcomes, providing an aid to decision makers in the public and private sectors that allows increased understanding of the implications of each scenario for each sector by summarizing projected outcomes to allow evaluation of the scenarios and comparison of choices and facilitate the essential dialogue between these sectors.

Moreno-Paz, M., Gómez-Cifuentes, A., Ruiz-Bermejo, M., Hofstetter, O., Maquieira, Á., Manchado, J.M., Morais, S., Sephton, M.A., Niessner, R., Knopp, D., Parro, V., 2018. Detecting nonvolatile life- and nonlife-derived organics in a carbonaceous chondrite analogue with a new multiplex immunoassay and its relevance for planetary exploration. Astrobiology 18, 1041-1056.


Potential martian molecular targets include those supplied by meteoritic carbonaceous chondrites such as amino acids and polycyclic aromatic hydrocarbons and true biomarkers stemming from any hypothetical martian biota (organic architectures that can be directly related to once living organisms). Heat extraction and pyrolysis-based methods currently used in planetary exploration are highly aggressive and very often modify the target molecules making their identification a cumbersome task. We have developed and validated a mild, nondestructive, multiplex inhibitory microarray immunoassay and demonstrated its implementation in the SOLID (Signs of Life Detector) instrument for simultaneous detection of several nonvolatile life- and nonlife-derived organic molecules relevant in planetary exploration and environmental monitoring. By utilizing a set of highly specific antibodies that recognize D- or L- aromatic amino acids (Phe, Tyr, Trp), benzo[a]pyrene (B[a]P), pentachlorophenol, and sulfone-containing aromatic compounds, respectively, the assay was validated in the SOLID instrument for the analysis of carbon-rich samples used as analogues of the organic material in carbonaceous chondrites or even Mars samples. Most of the antibodies enabled sensitivities at the 1–10 ppb level and some even at the ppt level. The multiplex immunoassay allowed the detection of B[a]P as well as aromatic sulfones in a water/methanol extract of an Early Cretaceous lignite sample (c.a., 140 Ma) representing type IV kerogen. No L- or D-aromatic amino acids were detected, reflecting the advanced diagenetic stage and the fossil nature of the sample. The results demonstrate the ability of the liquid extraction by ultrasonication and the versatility of the multiplex inhibitory immunoassays in the SOLID instrument to discriminate between organic matter derived from life and nonlife processes, an essential step toward life detection outside Earth.

Mu, L., von Solms, N., 2018. Experimental study on methane production from hydrate-bearing sandstone by flue gas swapping. Energy & Fuels 32, 8167-8174.


Methane recovery from artificial hydrate-bearing sandstones by simulated flue gas swapping was tested using a core flooding experimental setup. Seven groups of experiments were conducted to investigate the effect of hydrate saturation as well as the initial porosity and permeability of sandstones on methane production and carbon dioxide capture. The results show that the CH4 recovery efficiency and the amount of CO2 captured increase with the increase of hydrate saturation at the same initial porosity and permeability of sandstone. The highest CH4 recovery obtained is 51.6% and 99.4% of CO2 in simulated flue gas is sequestered in the hydrate phase after swapping at 9.2 MPa and 277.15 K. Hydrate saturation was 82.5% and the initial porosity and permeability of sandstone are 25.1% and 49 mD, respectively. With the increase of initial porosity and permeability of sandstone, the CH4 recovery efficiency and the amount of CO2 captured increase when other conditions (the hydrate saturation and reaction time) are similar. For investigating the CH4–flue gas swapping mechanism, a microdifferential scanning calorimetry was used to test the heat changes in the whole reaction. No noticeable endothermic or exothermic phenomenon was detected in the CH4–flue gas swapping, which indicates that CH4 hydrate would form mixed hydrates directly instead of going through a dissociation and reformation process. Based on the observed experimental results, a CH4–flue gas swapping mechanism is proposed and the reaction process is found to be essentially controlled by mass transfer.

Müller, O., Seuthe, L., Bratbak, G., Paulsen, M.L., 2018. Bacterial response to permafrost derived organic matter input in an Arctic fjord. Frontiers in Marine Science 5, :263. doi: 10.3389/fmars.2018.00263.

https://www.frontiersin.org/article/10.3389/fmars.2018.00263

The warming of the Arctic causes increased riverine discharge, coastal erosion, and the thawing of permafrost. Together, this is leading to an increased wash out of terrestrial dissolved organic matter (tDOM) into the coastal Arctic ecosystems. This tDOM may be anticipated to affect both carbon and nutrient flow in the microbial food web and microbial community composition, but there are few studies detailing this in Arctic marine ecosystems. We tested the effects of tDOM on the bacterial community composition and net-growth by extracting DOM from the active layer of permafrost soil and adding the aged tDOM concentrate to a natural microbial fjord community (Kongsfjorden, NW Svalbard). This resulted in an increased carbon load of 128 μM DOC in the tDOM treatment relative to the control of 83 μM DOC. We observed changes in community composition and activity in incubations already within 12 h where tDOM was added. Flow cytometry revealed that predominantly large bacteria increased in the tDOM treated incubations. The increase of this group correlated with the increase in relative abundance of the genus Glaciecola (Gammaproteobacteria). Glaciecola were initially not abundant in the bacterial community (0.6%), but their subsequent increase up to 47% after 4 days upon tDOM addition compared to 8% in control incubations indicates that they are likely capable of degrading permafrost derived DOM. Further, according to our experimental results we hypothesize that the tDOM addition increased bacterivorous grazing by small protists and thus tDOM might indirectly also effect higher trophic levels of the microbial food web.

Müller, R.D., Cannon, J., Qin, X., Watson, R.J., Gurnis, M., Williams, S., Pfaffelmoser, T., Seton, M., Russell, S.H.J., Zahirovic, S., 2018. GPlates: Building a virtual Earth through deep time. Geochemistry, Geophysics, Geosystems 19, 2243-2261.

https://doi.org/10.1029/2018GC007584

Abstract: GPlates is an open‐source, cross‐platform plate tectonic geographic information system, enabling the interactive manipulation of plate‐tectonic reconstructions and the visualization of geodata through geological time. GPlates allows the building of topological plate models representing the mosaic of evolving plate boundary networks through time, useful for computing plate velocity fields as surface boundary conditions for mantle convection models and for investigating physical and chemical exchanges of material between the surface and the deep Earth along tectonic plate boundaries. The ability of GPlates to visualize subsurface 3‐D scalar fields together with traditional geological surface data enables researchers to analyze their relationships through geological time in a common plate tectonic reference frame. To achieve this, a hierarchical cube map framework is used for rendering reconstructed surface raster data to support the rendering of subsurface 3‐D scalar fields using graphics‐hardware‐accelerated ray‐tracing techniques. GPlates enables the construction of plate deformation zones—regions combining extension, compression, and shearing that accommodate the relative motion between rigid blocks. Users can explore how strain rates, stretching/shortening factors, and crustal thickness evolve through space and time and interactively update the kinematics associated with deformation. Where data sets described by geometries (points, lines, or polygons) fall within deformation regions, the deformation can be applied to these geometries. Together, these tools allow users to build virtual Earth models that quantitatively describe continental assembly, fragmentation and dispersal and are interoperable with many other mapping and modeling tools, enabling applications in tectonics, geodynamics, basin evolution, orogenesis, deep Earth resource exploration, paleobiology, paleoceanography, and paleoclimate.

Plain Language Summary: The GPlates virtual globe software provides the capability to reconstruct geodata attached to tectonic plates to develop and modify models that describe how the plates and their boundaries have evolved through time. It allows users to deform plates and to visualize surface tectonics in the context of convecting mantle structure and evolution by importing seismic tomography models or outputs from geodynamic models. GPlates applications include tectonics, geodynamics, basin evolution, orogenesis, deep Earth resource exploration, paleobiology, paleoceanography, and paleoclimate. The software is enabling end‐users in universities, government organizations, industry, and schools to explore the evolution of planet Earth on their desktop.

Murphy, R.C., 2018. Challenges in mass spectrometry-based lipidomics of neutral lipids. TrAC Trends in Analytical Chemistry 107, 91-98.


Mass spectrometry has played a critical role in the identification and quantitation of neutral lipids such as cholesteryl esters and triacylglycerols present in biological extracts. Various strategies have emerged in order to carry out such lipidomics studies since a large number of neutral lipid molecular species exist in tissues. These include both shotgun approaches as well as those engaging liquid chromatographic separation of species prior to mass spectrometric analysis. Nonetheless challenges remain at every level of the lipidomics experiment, including extraction of lipids, identification of specific species, and quantitation of the vast array of lipids present in the sample extract. Unambiguous identification of molecular species present (qualitative analysis) as well as precise quantitation remains as significant challenges. The relative quantitation enables quite accurate

assessment of fold changes of complex lipid species without exact quantitation. The availability of reference standard material as well as relevant internal standards continue to be limited.

Muscalu, A.M., Górecki, T., 2018. Comprehensive two-dimensional gas chromatography in environmental analysis. TrAC Trends in Analytical Chemistry 106, 225-245.


Comprehensive two-dimensional gas chromatography (GC × GC) offers increased peak capacity and selectivity relative to conventional one dimensional separations. The analysis of persistent organic pollutants in environmental matrices is very challenging due to the large number of compounds with varying chemical and physical properties that are typically present in the sample at the same time at concentrations ranging from ultra-trace to percent levels. GC × GC is steadily gaining in popularity in environmental analysis and the number of publications citing the use of this technique has been increasing significantly in the recent years. An overview of the latest applications in the environmental field is presented in this paper, emphasizing the advances for targeted and non-targeted analysis in complex matrices. In addition, instrumentation, data interpretation approaches, as well as the quality assurance and control for routine analyzes are discussed.



Various types of coal waste material (fresh, self-heated, soil-covered) and river sediments polluted by coal dust were studied. Characteristic geochemical features of recent vegetation input in river sediments were identified, e.g. the dominance of n-alkanols and n-alkanoic acids over n-alkanes. In the river sediments, several coal-related compounds were also found, e.g. n-alkylbenzenes, acetophenone and methylated phenols. The occurrence of sterols, stanols, vanillin, and methylbenzoic, benzeneacetic, oxalic, succinic and levulinic acids in coal waste samples (with the exception of fresh coal wastes) may indicate primitive soil-forming processes related to vegetation and moss cover. These compounds were also commonly identified in river sediments. Their distribution, characteristic of extant (as opposed to fossil) organic matter, was confirmed by several applied geochemical ratios, such as the EOP index (even-over-odd predominance) of fatty acids, (Σn-alkanoic acid + Σlong chain n-alkanes)/Σshort chain n-alkanes or (Σn-alkanoic acids + Σn-alkanols)/Σn-alkanes and various CPI (carbon preference indexes of n-alkanes).

Narduzzi, L., Franciosi, E., Carlin, S., Tuohy, K., Beretta, A., Pedrotti, F., Mattivi, F., 2018. Applying novel approaches for GC × GC-TOF-MS data cleaning and trends clustering in VOCs time-series analysis: Following the volatiles fate in grass baths through passive diffusion sampling. Journal of Chromatography B 1096, 56-65.


Phytothermotherapy (“grass baths”) is a traditional phytotherapy for rheumatism consisting of taking baths in hot fermenting grass. Scientific studies have demonstrated its efficiency in treating several rheumatic diseases. However the efficiency and repeatability of the therapy is dependent on the wild fermentations, determining sometimes the appearance of unpleasant conditions leading to the early

abandonment of the therapy. The metabolism undergoing in the grass baths is unknown and there is not an established method to evaluate and predict grass baths quality.

The aim of this study is to establish a simple VOCs profiling method able to evaluate the grass baths, predicting their evolution, through the identification of marker volatiles related to the best conditions and/or the spoilage. After replicating in real scale the traditional grass baths, the volatile profiles were measured using passive diffusion samplers injected in a thermal desorption-comprehensive GC × GC-TOF-MS. The high dimensionality of the data coupled with the limited number of time points, required a rigorous method development for the analysis of the data, achieved through the development of a novel R package for variable selection in GC × GC data matrices. The further application of a fuzzy clustering approach demonstrated to be a useful tool dealing with short time series, allowing to discard un-trending volatiles and giving a clear snapshot of the main trends in the data. A broad coverage of the volatolome was provided, thus suitable to describe the main metabolic changes ongoing in the grass baths. Coupling this data with the temperature and pH, and comparing it to the data from similar processes, like silage and compost, we demonstrated that the established method can be helpful to evaluate short time series, allowing us to obtain a list of volatiles as candidate markers for the quality of the grass baths.

The established method gave a list of markers applicable to real scale grass baths to predict spoilage; furthermore it provides a list of volatiles where to search for candidate markers with reported health-related effects and can be used to generate hypothesis on the mechanisms of action of the treatment.

Nascimento, F.J.A., Lallias, D., Bik, H.M., Creer, S., 2018. Sample size effects on the assessment of eukaryotic diversity and community structure in aquatic sediments using high-throughput sequencing. Scientific Reports 8, Article 11737.

https://doi.org/10.1038/s41598-018-30179-1

Understanding how biodiversity changes in time and space is vital to assess the effects of environmental change on benthic ecosystems. Due to the limitations of morphological methods, there has been a rapid expansion in the application of high-throughput sequencing methods to study benthic eukaryotic communities. However, the effect of sample size and small-scale spatial variation on the assessment of benthic eukaryotic diversity is still not well understood. Here, we investigate the effect of different sample volumes in the genetic assessment of benthic metazoan and non-metazoan eukaryotic community composition. Accordingly, DNA was extracted from five different cumulative sediment volumes comprising 100% of the top 2 cm of five benthic sampling cores, and used as template for Ilumina MiSeq sequencing of 18 S rRNA amplicons. Sample volumes strongly impacted diversity metrics for both metazoans and non-metazoan eukaryotes. Beta-diversity of treatments using smaller sample volumes was significantly different from the beta-diversity of the 100% sampled area. Overall our findings indicate that sample volumes of 0.2 g (1% of the sampled area) are insufficient to account for spatial heterogeneity at small spatial scales, and that relatively large percentages of sediment core samples are needed for obtaining robust diversity measurement of both metazoan and non-metazoan eukaryotes.

Navarro-Reig, M., Jaumot, J., Tauler, R., 2018. An untargeted lipidomic strategy combining comprehensive two-dimensional liquid chromatography and chemometric analysis. Journal of Chromatography A 1568, 80-90.


Untargeted lipidomic samples are extremely complex and often exceed the limits of peak capacity achievable by one-dimensional liquid chromatography (LC). Comprehensive two-dimensional liquid chromatography (LC × LC) appears as a promising alternative to overcome this drawback. Unfortunately, this approach generates highly complex datasets which untargeted analysis is challenging. In this work, a global methodological strategy combining LC × LC–MS/MS with chemometric data analysis is proposed for untargeted lipidomic studies. The feasibility of the proposed methodology is demonstrated by its application to assess the effects of arsenic exposure on the lipidome of growing rice samples. A two-dimensional chromatographic setup coupling reversed phase (RP) and hydrophilic interaction liquid chromatography (HILIC) modes together with a triple quadrupole mass detector (TQD) is proposed to analyze lipid extracts from rice samples at different experimental conditions. Chemometric tools were used for data compression, spectral and elution profiles resolution, feature detection and statistical analysis of the multidimensional LC × LC–MS/MS data. The obtained results revealed that the proposed methodology was useful to gather relevant information from untargeted lipidomic studies and detect potential biomarkers.

Nawaz, A., Purahong, W., Lehmann, R., Herrmann, M., Totsche, K.U., Küsel, K., Wubet, T., Buscot, F., 2018. First insights into the living groundwater mycobiome of the terrestrial biogeosphere. Water Research 145, 50-61.


Although fungi play important roles in biogeochemical cycling in aquatic ecosystems and have received a great deal of attention, much remains unknown about the living fractions of fungal communities in aquifers of the terrestrial subsurface in terms of diversity, community dynamics, functional roles, the impact of environmental factors and presence of fungal pathogens. Here we address this gap in knowledge by using RNA-based high throughput pair-end illumina sequencing analysis of fungal internal transcribed spacer (ITS) gene markers, to target the living fractions of groundwater fungal communities from fractured alternating carbonate-/siliciclastic-rock aquifers of the Hainich Critical Zone Exploratory. The probed levels of the hillslope multi-storey aquifer system differ primarily in their oxygen and nitrogen content due to their different connections to the surface. We discovered highly diverse living fungal communities (384 Operational Taxonomic Units, OTUs) with different taxonomic affiliations and ecological functions. The observed fungal communities primarily belonged to three phyla: Ascomycota, Basidiomycota and Chytridiomycota. Perceived dynamics in the composition of living fungal communities were significantly shaped by the concentration of ammonium in the moderately agriculturally impacted aquifer system. Apart from fungal saprotrophs, we also detected living plant and animal pathogens for the first time in this aquifer system. This work also demonstrates that the RNA-based high throughput pair-end illumina sequencing method can be used in future for water quality monitoring in terms of living fungal load and subsequent risk assessments. In general, this study contributes towards the growing knowledge of aquatic fungi in terrestrial subsurface biogeosphere.

Nelabhotla, A.B.T., Dinamarca, C., 2018. Electrochemically mediated CO2 reduction for bio-methane production: a review. Reviews in Environmental Science and Bio/Technology 17, 531-551.

https://doi.org/10.1007/s11157-018-9470-5

A number of methods for carbon capture, more specifically, CO2 capture have been researched in the past few years. One such method is electrochemical CO2 reduction to biomethane which also serves the purpose of biogas upgradation using microbial electrosynthesis systems. This technology is also known as Power to Gas technology and the review starts with the importance and requirement of PtG

in the modern world by studying energy production and consumption patterns in Europe, with a focus on Norway. The paper summarises the recent works and concepts in the field of bioelectrochemical systems with a focus on electron transfer mechanisms, biocatalysts and reactor designs. Works and gaps in the studies of direct interspecies electron transfer and biocathode developments are discussed in detail. This is followed by a discussion explaining various reactor designs, the advantages of single chambered microbial reactors and the importance of reactors that combine anaerobic digestion with microbial electrolysis cells.

Nemirovskaya, I.A., Redzhepova, Z.Y., 2018. Behavior of hydrocarbons in the mouth parts of Arctic rivers. Geochemistry International 56, 828-841.

https://doi.org/10.1134/S0016702918080074

The paper reviews data (acquired in 2007–2016) on aliphatic and polycyclic aromatic hydrocarbons in comparison with data on concentrations of lipids, Corg, and chlorophyll a in the water and bottom sediments the river–sea geochemical barrier (for the Northern Dvina, Ob, Yenisei, and Lena rivers). It was established that the concentrations of anthropogenic hydrocarbons decrease and these compounds precipitate like other organic compounds and particulate matter, where riverine and marine waters mix. Relatively pure water flows in the pelagic zones of seas. In spite of low temperatures in the Arctic, anthropogenic hydrocarbons transform so rapidly that natural compounds dominate in the water and bottom sediments: autochthonous in the seawater and allochthonous in the bottom sediments. Original Russian Text © I.A. Nemirovskaya, Z.Yu. Redzhepova, 2018, published in Geokhimiya, 2018, No. 8, pp. 791–804.

Netzer, R., Henry, I.A., Ribicic, D., Wibberg, D., Brönner, U., Brakstad, O.G., 2018. Petroleum hydrocarbon and microbial community structure successions in marine oil-related aggregates associated with diatoms relevant for Arctic conditions. Marine Pollution Bulletin 135, 759-768.


Oil-related aggregates (ORAs) may contribute to the fate of oil spilled offshore. However, our understanding about the impact of diatoms and associated bacteria involved in the formation of ORAs and the fate of oil compounds in these aggregates is still limited. We investigated these processes in microcosm experiments with defined oil dispersions in seawater at 5 °C, employing the Arctic diatom Fragilariopsis cylindrus and its associated bacterial assemblage to promote ORA formation. Accumulation of oil compounds, as well as biodegradation of naphthalenes in ORAs and corresponding water phases, was enhanced in the presence of diatoms. Interestingly, the genus Nonlabens was predominating the bacterial communities in diatom-supplemented microcosms, while this genus was not abundant in other samples. This work elucidates the relevance of diatom biomass for the formation of ORAs, microbial community structures and biodegradation processes in chemically dispersed oil at low temperatures relevant for Arctic conditions.

Nguyen, N.T., Kang, K.H., Lee, C.W., Kim, G.T., Park, S., Park, Y.-K., 2019. Structure comparison of asphaltene aggregates from hydrothermal and catalytic hydrothermal cracking of C5-isolated asphaltene. Fuel 235, 677-686.


The main purpose of this study is to elucidate the effect of catalyst on asphaltene molecular structure during hydrocracking of C5-isolated asphaltene. Remained asphaltene and coke were obtained after

hydrothermal and catalytic hydrothermal cracking of C5-isolated asphaltene at 380–430 °C, using 1000 ppm Mo from Mo-octoate precursor. XRD and NMR analyses were used to investigate the change of molecular structure of asphaltene during the reaction. It was revealed that aggregation of asphaltene increased with increasing the reaction severity resulted in coke formation. The presence of catalyst reduced the aggregation of asphaltene molecules in comparison with the hydrothermal cracking. It was also observed that the average number of stacked polyaromatic sheets in the remained asphaltene decreased with increasing the reaction temperature because of the transformation of high stacked asphaltene into coke during the reaction. Moreover, it was confirmed that the main reason for asphaltene aggregation was the reduction of steric hindrance of asphaltene molecules by the change in molecular structure of asphaltenes.

Ni, X., Groffman, P.M., 2018. Declines in methane uptake in forest soils. Proceedings of the National Academy of Sciences 115, 8587-8590.

http://www.pnas.org/content/115/34/8587.abstract

Significance: Atmospheric methane (CH4) concentration has been increasing rapidly over recent decades. Forest soils are a major sink for atmospheric CH4, but evidence from long-term in situ observation is limited, so little is known about how the soil CH4 sink responds to changing environmental conditions. We measured soil to atmosphere net CH4 fluxes at long-term ecological research sites in Baltimore, Maryland (1998–2016) and Hubbard Brook, New Hampshire (2002–2015) and found significant decreases in CH4 uptake at both sites. Moreover, a literature review showed that CH4 uptake in forest soils around the world is also declining, especially forests from 0–60 °N latitude, where precipitation has been increasing. We conclude that the current soil CH4 sink may be overestimated over large regional areas.

Abstract: Forest soils are a sink for atmospheric methane (CH4) and play an important role in modulating the global CH4 budget. However, whether CH4 uptake by forest soils is affected by global environmental change is unknown. We measured soil to atmosphere net CH4 fluxes in temperate forests at two long-term ecological research sites in the northeastern United States from the late 1990s to the mid-2010s. We found that annual soil CH4 uptake decreased by 62% and 53% in urban and rural forests in Baltimore, Maryland and by 74% and 89% in calcium-fertilized and reference forests at Hubbard Brook, New Hampshire over this period. This decrease occurred despite marked declines in nitrogen deposition and increases in atmospheric CH4 concentration and temperature, which should lead to increases in CH4 uptake. This decrease in soil CH4 uptake appears to be driven by increases in precipitation and soil hydrological flux. Furthermore, an analysis of CH4 uptake around the globe showed that CH4 uptake in forest soils has decreased by an average of 77% from 1988 to 2015, particularly in forests located from 0 to 60 °N latitude where precipitation has been increasing. We conclude that the soil CH4 sink may be declining and overestimated in several regions across the globe.

Ni, Y., Chen, Z., Fu, Y., Liu, Y., Zhu, W., Liu, Z., 2018. Selective conversion of CO2 and H2 into aromatics. Nature Communications 9, Article 3457.

https://doi.org/10.1038/s41467-018-05880-4

Transformation of greenhouse gas CO2 and renewable H2 into fuels and commodity chemicals is recognized as a promising route to store fluctuating renewable energy. Although several C1 chemicals, olefins, and gasoline have been successfully synthesized by CO2 hydrogenation, selective conversion of CO2 and H2 into aromatics is still challenging due to the high unsaturation degree and

complex structures of aromatics. Here we report a composite catalyst of ZnAlOx and H-ZSM-5 which yields high aromatics selectivity (73.9%) with extremely low CH4 selectivity (0.4%) among the carbon products without CO. Methanol and dimethyl ether, which are synthesized by hydrogenation of formate species formed on ZnAlOx surface, are transmitted to H-ZSM-5 and subsequently converted into olefins and finally aromatics. Furthermore, 58.1% p-xylene in xylenes is achieved over the composite catalyst containing Si-H-ZSM-5. ZnAlOx&H-ZSM-5 suggests a promising application in manufacturing aromatics from CO2 and H2.

Nielsen, C., Brunet, T., Arendt, D., 2018. Evolution of the bilaterian mouth and anus. Nature Ecology & Evolution 2, 1358-1376.

https://doi.org/10.1038/s41559-018-0641-0

It is widely held that the bilaterian tubular gut with mouth and anus evolved from a simple gut with one major gastric opening. However, there is no consensus on how this happened. Did the single gastric opening evolve into a mouth, with the anus forming elsewhere in the body (protostomy), or did it evolve into an anus, with the mouth forming elsewhere (deuterostomy), or did it evolve into both mouth and anus (amphistomy)? These questions are addressed by the comparison of developmental fates of the blastopore, the opening of the embryonic gut, in diverse animals that live today. Here we review comparative data on the identity and fate of blastoporal tissue, investigate how the formation of the through-gut relates to the major body axes, and discuss to what extent evolutionary scenarios are consistent with these data. Available evidence indicates that stem bilaterians had a slit-like gastric opening that was partially closed in subsequent evolution, leaving open the anus and most likely also the mouth, which would favour amphistomy. We discuss remaining difficulties, and outline directions for future research.

Nikolaev, V.F., Foss, L.E., Ilyasov, R.A., Timirgalieva, A.K., Shageev, A.F., 2019. Method for laboratory testing of solvents for enhanced oil recovery based on dispersiometry and thin layer chromatography. Fuel 235, 433-436.


We suggest a method to be used in laboratory testing of solvents for enhanced oil recovery based on thin layer chromatography. All solvents may be described with the help of the separation factor and solvent time. The former is defined by the position of the geometrical center of track left by the dark oil components, which characterizes the elution ability of the solvent. The latter is defined by the time it takes the solvent front to reach the final mark, which characterizes its wettability. The wetting ability of the solvent can be estimated using the multiplicative factors of the equation, describing the motion of the solvent front on the plate in time. We used the TLC silica plates (Silufol/Sorbfil) as a model of porous sandstone reservoirs. Each solvent was characterized by dispersion of the refractive index as one of the criteria for ranking solvents by their efficiency.

Nissanka, I.D., Yapa, P.D., 2018. Calculation of oil droplet size distribution in ocean oil spills: A review. Marine Pollution Bulletin 135, 723-734.


Calculation of oil droplet size distribution is one of the key components of ocean oil spill models. Oil fate and transport calculations of the model are significantly impacted by the droplet size distribution. Accuracy of the model predictions heavily depend on how well the model can calculate or represent

oil droplet sizes. However, in early oil spill models, the importance of oil droplet size calculation has been overlooked and they used simple empirical formulas. In recent decades, there have been some significant improvements in understanding of oil droplet size calculations. Both experimental studies as well as numerical studies have been contributed to improve oil droplet size calculations. The traditional equilibrium models have been improved while droplet dynamics models provided a different dimension to the oil DSD calculations. Thus, at this stage it is important to review the existing studies and methods of oil droplet size calculation. The objective of this paper is to review the development of oil droplet size calculation in ocean oil spill models highlighting the recent improvements. Furthermore, this paper discusses the capabilities and limitations of different approaches in calculating oil droplet size distribution in both underwater and surface oil spill models and discuss their applicability to different situations. This study will provide a good guideline for future oil spill model developments to improve the oil droplet size calculations.

Nole, M., Daigle, H., Cook, A.E., Malinverno, A., Flemings, P.B., 2018. Burial-driven methane recycling in marine gas hydrate systems. Earth and Planetary Science Letters 499, 197-204.


Natural gas hydrate may be buried with sediments until it is no longer stable at a given pressure and temperature, resulting in conversion of hydrate into free gas. This gas may migrate upward and recycle back into the hydrate stability zone to form hydrate. As of yet, however, no quantitative description of the methane recycling process has been developed using multiphase flow simulations to model burial-driven gas hydrate recycling. In this study, we present a series of 1D multiphase transport simulations to investigate the methane recycling process in detail. By invoking the effects of capillary phenomena on hydrate and gas formation in pores of varying size, we find that a free gas phase can migrate a significant distance above the bulk base of hydrate stability. Since the top of the free gas occurrence is often identified as the base of the hydrate stability zone from seismic data, our results demonstrate that not only could this assumption mischaracterize a hydrate system, but that under recycling conditions the highest hydrate saturations can occur beneath the top of the free gas occurrence. We show that the presence of pore size distributions requires a replacement zone through which hydrate saturations progressively decrease with depth and are replaced with free gas. This replacement zone works to buffer against significant gas buildup that could lead to fracturing of overlying sediments. This work provides a framework for simulating flow and transport of methane within the 3-phase stability zone from a mass conservation perspective.

Nunn, J.A., Xiang, Y., Al, T.A., 2018. Investigation of partial water saturation effects on diffusion in shale. Applied Geochemistry 97, 93-101.


A new method for testing the effect of partially saturated conditions on aqueous diffusion was developed using samples from the Upper Ordovician Queenston Formation shale from the Michigan Basin of southwest Ontario, Canada. Effective diffusion coefficients (De) were determined for iodide tracer on duplicate cm-scale samples from a core segment. Partially saturated conditions were created with a new gas-ingrowth method that takes advantage of the variability of N2 solubility with pressure. The method is designed to create partially saturated pores, quantify the level of partial gas/brine saturation within the tracer-accessible pore space, and measure De under fully porewater-saturated and partially gas-saturated conditions for the same sample. X-ray radiography is used with an iodide tracer for quantifying the degree of partial saturation and measuring De. The saturated De values range from 2.8 × 10−12 to 3.1 × 10−12 m2/s. Following generation of a gas phase in the pores (average gas

saturations of 4–6.7%), De values decrease by 20–22% relative to the porewater-saturated condition, indicating that the tortuosity factor (ratio of constrictivity to tortuosity) is sensitive to saturation. The data suggest that a relatively small fraction of the pore space dominates the solute transport. The gas-ingrowth method was successful for generating partial gas saturation, but the distribution of the gas phase is non-uniform, with relatively high gas saturations near boundaries and lower saturations in the interior of the samples.

O'Dogherty, L., Aguado, R., Baumgartner, P.O., Bill, M., Goričan, Š., Sandoval, J., Sequeiros, L., 2018. Carbon-isotope stratigraphy and pelagic biofacies of the Middle–Upper Jurassic transition in the Tethys–Central Atlantic connection. Palaeogeography, Palaeoclimatology, Palaeoecology 507, 129-144.


A bulk carbon-isotope stratigraphy, based on high-resolution sampling of five stratigraphic ammonite-dated sections from pelagic swells of the Subbetic basin (External Zones of the Betic Cordillera, southern Spain) is presented. The studied sections are characterized by Callovian–Oxfordian stratigraphic successions located in the South Iberian palaeomargin, a key area connecting the Central Atlantic to the Tethys oceans. The rocks are mainly nodular limestones with common extreme condensation (rosso ammonitico facies). Discontinuities with hiatuses of variable duration, submarine “hardgrounds”, Fe-Mn ooids, limonite crusts, and neptunian dykes are observed around the Callovian/Oxfordian boundary. The stratigraphic record, although very time-averaged, allows for a consistent and accurate ammonite chronostratigraphy. The carbon isotopes of marine carbonates show a marked trend towards high δ13C values from Lower Oxfordian to the Middle Oxfordian (~4.3‰, near the Plicatilis/Transversarium boundary). The isotopic values stand between 2.7 and 3.0‰ at the Upper Oxfordian (Bifurcatus and Hypselum Zones) and lowermost Kimmeridgian (Bimammatum Zone); afterward δ13C values decrease and reach a relative minimum (~2.3–2.5‰) in the Lower Kimmeridgian (Bimammatum/Planula boundary). Finally, isotopic values increase again (~2.6–2.7‰) in the lower Kimmeridgian (mid part of the Planula Zone). Comparison of carbon-isotope stratigraphy between Subbetic and other Tethyan areas shows similar trends. The replacement of thin-shelled bivalves by planktonic foraminifers and radiolarians that took place in the Callovian/Oxfordian boundary can be associated to the widening of the trans-Pangaean seaway. This, in turn, triggered the global warming which increased nutrients concentration in upper water column due to intensified nutrient input by river plumes. These phenomena are concomitant with the major Oxfordian δ13C positive excursion and with a transgressive cycle.

O’Connell, J.F., Allen, J., Williams, M.A.J., Williams, A.N., Turney, C.S.M., Spooner, N.A., Kamminga, J., Brown, G., Cooper, A., 2018. When did Homo sapiens first reach Southeast Asia and Sahul? Proceedings of the National Academy of Sciences 115, 8482-8490.


Anatomically modern humans (Homo sapiens, AMH) began spreading across Eurasia from Africa and adjacent Southwest Asia about 50,000–55,000 years ago (ca. 50–55 ka). Some have argued that human genetic, fossil, and archaeological data indicate one or more prior dispersals, possibly as early as 120 ka. A recently reported age estimate of 65 ka for Madjedbebe, an archaeological site in northern Sahul (Pleistocene Australia–New Guinea), if correct, offers what might be the strongest support yet presented for a pre–55-ka African AMH exodus. We review evidence for AMH arrival on an arc spanning South China through Sahul and then evaluate data from Madjedbebe. We find that an age estimate of >50 ka for this site is unlikely to be valid. While AMH may have moved far beyond

Africa well before 50–55 ka, data from the region of interest offered in support of this idea are not compelling.

Ogunyomi, B.A., Dong, S., La, N., Lake, L.W., Kabir, C.S., 2018. An approach to modeling production decline in unconventional reservoirs. Journal of Petroleum Exploration and Production Technology 8, 871-886.

https://doi.org/10.1007/s13202-017-0380-9

Most decline curve methods have two main limitations; the model parameters as a rule are not functions of reservoir parameters and may yield unrealistic (nonphysical) values of expected ultimate recovery (EUR) because boundary-dominated flow may not develop in unconventional reservoirs. Over the past few years, several empirical models have emerged to address the second limitation, but they are challenged by the time to transition from infinite-acting flow period to the boundary-dominated flow. In this study, we performed statistical and model-based analysis of production data from hydraulically fractured horizontal oil wells and present a method to mitigate some of the limitations highlighted above. The production data were carefully analyzed to identify the flow regimes and understand the overall decline behavior. Following this step, we performed model-based analysis using the parallel flow model (sum of exponential terms), and the logistic growth model. After the model-based analysis, the model parameters were analyzed statistically and cross-plotted against available reservoir and well completion parameters. Based on the conclusion from the cross-plots and statistical analysis, we used design of experiments (DoE) and numerical reservoir simulations to develop functions that relate the model parameters and reservoir/well completion properties. Results from this work indicate that the production characteristics from these wells are highly variable. In addition, the parallel flow model indicates that there are at least two to three different time domains in the production behavior and that they are not the result of operational changes, such as well shut-in or operating pressure changes at the surface. All the models used in this study provide very good fits to the data, and all provide realistic estimates of EUR. The cross-plots of model parameters and some reservoir/well completion properties indicate that there is some relationship between them, which we developed using DoE and flow simulations. We have also shown how these models can be applied to obtain realistic estimates of EUR from early-time production data in unconventional oil reservoirs.

Okamoto, S., Honda, T., Miyakoshi, T., Han, B., Sablier, M., 2018. Application of pyrolysis-comprehensive gas chromatography/mass spectrometry for identification of Asian lacquers. Talanta 189, 315-323.


A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of lacquer saps with potential applications to analysis of Asian lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low μg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar

lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian lacquer saps, and is very promising for sensitive detection of lacquers in archaeological artifacts.


https://doi.org/10.1007/s00253-018-9203-2

Methane (CH4) is a powerful greenhouse gas emitted from natural and anthropogenic sources, and its emission rates vary among sources as a function of environment, microbial respiration, and feedbacks. Biological CH4 flux from natural and engineered systems is typically represented simply as generation of CH4 by methanogens minus oxidation by methanotrophs. In many cases, however, CH4 flux is modulated by transport and solubility mechanisms that occur before oxidation or other chemical transformation. The ability of fungi to directly oxidize CH4 remains unclear; however, their hydrophobic growths extending above microbial biofilms can improve surface area and sorption of hydrophobic gases. This can improve overall oxidation rates in a biofilm simply by improving phase transfer dynamics and bioavailability to bacterial or archaeal associates. This indirect facilitation is not necessarily intuitive, but there has been a recent emerging interest in harnessing these fungal abilities in engineering bioreactors and filtration systems designed to capture and oxidize CH4. These dynamics may be playing a similar facilitative role in natural CH4 oxidation, where fungi may indirectly influence carbon mineralization and methanogen/methanotroph communities, and/or directly oxidize and dissolve gaseous CH4. This review highlights these unique roles for fungi in determining net CH4 oxidation rates, and it summarizes the potential to harness fungi to mitigate CH4 emissions.

Omrani, H., Raghimi, M., 2018. Origin of the mud volcanoes in the south east Caspian Basin, Iran. Marine and Petroleum Geology 96, 615-626.


Abstract: The Gorgan Plain (SE Caspian Basin) contains several mud volcanoes. The Gharenyaregh, Neftlijeh, Sofikam and Inche mud volcanoes are active and erupting mud and gas. Mud volcanoes occur in an area characterized by seismic activity. The Sofikam mud volcano consists of five craters that define a NE-directed (60°) linear arrangement, which coincides with a subsurface anticline of the western Kopeh Dagh fold-thrust belt. The main craters of the Inche and Neftlijeh mud volcanoes are submerged. The Gharenyaregh mud volcano is an active mud volcano whose crater is nearly 500 m in diameter. Clasts collected from the Gharenyaregh mud volcano (GMV) mainly consist of glauconite-sandstone, limestone (±ammonite), marl, and fossiliferous limestone (lumachelle) with bioclasts ranging in size from millimeters to centimeters. X-ray diffraction (XRD) analyses revealed quartz, calcite, feldspar, chlorite, illite, glauconite, halite and gypsum minerals in the clasts and soft materials of the GMV. The clasts are comparable with rock fragments originating from the underlying Kopeh Dagh related formations and the uppermost Caspian basin sediments. Regression of the South Caspian Sea shoreline from east to west (across modern-day Golestan province), seismic activity and buried folds indicate that the south east Caspian basin mud volcanoes are located in a tectonically active area and generated from deeper parts of the Gorgan Plain. Some large, conical hills with a record of historical human activity, located between the Kopeh Dagh zone and the South Caspian Sea, seem to be inactive mud volcanoes.

Ossa Ossa, F., Hofmann, A., Wille, M., Spangenberg, J.E., Bekker, A., Poulton, S.W., Eickmann, B., Schoenberg, R., 2018. Aerobic iron and manganese cycling in a redox-stratified Mesoarchean epicontinental sea. Earth and Planetary Science Letters 500, 28-40.


Redox conditions in the marine realm prior to the Great Oxidation Event (GOE; ∼2.46–2.32 Ga ago), during which the atmospheric oxygen level rose dramatically for the first time, are still debated. Here, we present C, O, Fe, and Mo stable isotope systematics of Fe-, Mn-, and carbonate-rich shales, deposited at different water depths in association with iron formations (IFs) of the Mesoarchean Mozaan Group, Pongola Supergroup, South Africa. δ13C values between −22.3 and −13.5‰ VPDB, and δ18O values between −21.1 and −8.6‰ VPDB for Fe–Mn-rich carbonate minerals indicate their precipitation out of equilibrium with seawater. Instead, early diagenetic reduction of Fe–Mn-oxyhydroxide precursor minerals, along with microbially induced oxidation of organic matter (OM), formed these carbonates. δ56FeIRMM-014 values between −1.27 and 0.14‰ and δ98MoNIST3134+0.25 values between −0.46 and 0.56‰ co-vary with Mn concentrations and inferred water depth of deposition. This suggests that, despite the diagenetic origin of the Fe–Mn carbonates, the primary light Fe and Mo isotopic signature of Fe–Mn-oxyhydroxides that originally precipitated from seawater is still preserved. While isotopically light Mo implies that Mn(II) was oxidized to Mn(IV) due to the availability of free, photosynthetically produced O2, Mn enrichment suggests that the water column was redox stratified with a Mn-redoxcline situated at a depth below the storm wave base. A trend to highly negative δ56Fe values with increasing Mn/Fe ratios and decreasing depositional depth suggests progressive oxidation of Fe(II) as deep-waters upwelled across a redoxcline towards shallow, locally oxygenated waters where Mn(IV) oxyhydroxides precipitated. Combined δ56Fe and δ98Mo data indicate pervasive oxygenation of seawater with the O2 content in the photic zone likely reaching levels higher than the maximum value of 10 μM proposed for Archean oxygen oases. Since abiotic Mn(II) oxidation is kinetically very slow in marine environments, it is likely that Mn-oxidizing microorganisms catalyzed Mn-oxidation in the oxygenated Pongola surface waters during deposition of IFs. This implies that aerobic metabolism had evolved before the GOE in shallow, aquatic habitats, where it exerted a first-order control on the deposition of shallow-marine, Mn-rich iron formations.

Otwell, A.E., Callister, S.J., Sherwood, R.W., Zhang, S., Goldman, A.R., Smith, R.D., Richardson, R.E., 2018. Physiological and proteomic analyses of Fe(III)-reducing co-cultures of Desulfotomaculum reducens MI-1 and Geobacter sulfurreducens PCA. Geobiology 16, 522-539.


We established Fe(III)‐reducing co‐cultures of two species of metal‐reducing bacteria, the Gram‐positive Desulfotomaculum reducens MI‐1 and the Gram‐negative Geobacter sulfurreducens PCA. Co‐cultures were given pyruvate, a substrate that D. reducens can ferment and use as electron donor for Fe(III) reduction. G. sulfurreducens relied upon products of pyruvate oxidation by D. reducens (acetate, hydrogen) for use as electron donor in the co‐culture. Co‐cultures reduced Fe(III) to Fe(II) robustly, and Fe(II) was consistently detected earlier in co‐cultures than pure cultures. Notably, faster cell growth, and correspondingly faster pyruvate oxidation, was observed by D. reducens in co‐cultures. Global comparative proteomic analysis was performed to observe differential protein abundance during co‐culture vs. pure culture growth. Proteins previously associated with Fe(III) reduction in G. sulfurreducens, namely c‐type cytochromes and type IV pili proteins, were significantly increased in abundance in co‐cultures relative to pure cultures. D. reducens ribosomal proteins were significantly increased in co‐cultures, likely a reflection of faster growth rates observed for D. reducens cells while in co‐culture. Furthermore, we developed multiple reaction monitoring (MRM) assays to quantitate specific biomarker peptides. The assays were validated in pure and co‐

cultures, and protein abundance ratios from targeted MRM and global proteomic analysis correlate significantly.

Owen, R., Day, C.C., Henderson, G.M., 2018. CaveCalc: A new model for speleothem chemistry & isotopes. Computers & Geosciences 119, 115-122.


CaveCalc is a PHREEQC-based numerical model for cave dripwater and speleothem chemistry, designed to aid in the interpretation of speleothem palaeoclimate records and cave monitoring datasets.

CaveCalc forward-models dripwater and carbonate chemistry and isotopes through a variety of soil, karst and cave processes. Such processes include soil water & gas equilibration, carbonate bedrock dissolution, secondary carbonate precipitation and CO2 degassing. CaveCalc is able to quantitatively model bedrock dissolution under semi-open conditions — a feature necessary to accurately simulate the gas chemistry occurring in real cave environments.

The model allows coupled modelling of multiple proxy systems, including δ18O, δ13C, a14C, δ44/40Ca and trace-elements (Mg/Ca, Sr/Ca, Ba/Ca), within a single framework. Additional proxy systems, chemical processes and calibration data may be added to the model as required.

Owens, J.D., Lyons, T.W., Lowery, C.M., 2018. Quantifying the missing sink for global organic carbon burial during a Cretaceous oceanic anoxic event. Earth and Planetary Science Letters 499, 83-94.


The Cretaceous experienced numerous global and local climatic perturbations to the ocean–atmosphere system, especially during periods of known widespread organic-carbon burial termed oceanic anoxic events (OAEs). The Cenomanian–Turonian boundary event (∼93.9 Ma), or OAE-2, is the best documented and widespread organic carbon (OC) burial event in Earth history—with more than 170 sections published. Despite the substantial number of locations, the majority is found within the proto-Atlantic Ocean, Tethys Ocean and epicontinental seaways. It has been hypothesized that the pervasive burial of OC during OAE-2 caused the observed positive carbon isotope excursion (2 to 7‰, average ∼3‰). The isotope excursion can help constrain the global burial of OC, even for unstudied portions of the global ocean. This approach can solve for ‘missing’ OC sinks by comparing model estimates with the known distribution of OAE-2 sediments and their OC contents. Specifically, mapping the known spatial extent of OC burial in terms of mass accumulation rates (MARs), and comparing those results with the prediction using a forward box model to derive the amount of OC burial to reproduce the globally observed positive carbon isotope excursion. The available OC data from outcrop and drill core, with reasonable extrapolation to analogous settings without data, quantifies ∼13% of the total seafloor, mostly from marginal marine and epicontinental/epeiric settings. However, this extrapolation for OC burial, plus using most appropriate MARs to unknown portions of the seafloor, fail to account for the amount of OC burial predicted for a 3‰ positive carbon isotope excursion. This discrepancy remains even when considering additional sinks of organic carbon burial such as coal, lacustrine environments, authigenic carbonate, and the loss of OC associated with hydrocarbon reservoirs. This outcome points to a large reservoir of OC that is not currently constrained, such as highly productive margins and/or equatorial regions, or a small but significant increase deep ocean OC burial. Another possibility is that the carbon fluxes are less than

those used in the model which would require less OC burial to explain a ∼3‰ carbon isotope excursion.

Pala, C., Molari, M., Nizzoli, D., Bartoli, M., Viaroli, P., Manini, E., 2018. Environmental drivers controlling bacterial and archaeal abundance in the sediments of a Mediterranean lagoon ecosystem. Current Microbiology 75, 1147-1155.

https://doi.org/10.1007/s00284-018-1503-3

The environmental factors controlling the abundance of Bacteria and Archaea in lagoon ecosystems are poorly understood. Here, an integrated physico-chemical, biogeochemical, and microbiological survey was applied in the Sacca di Goro lagoon (Po River Delta, Italy) to investigate the variation of bacterial and archaeal abundance, as assessed by Fluorescence In Situ Hybridization, along winter and summer environmental gradients. We hypothesised that bacterial and archaeal cells respond differentially to physico-chemical parameters of the sediment, which can be manifested in variations of total cells number. Our results suggest that Archaea are an important component of microbial communities (up to 20%) and they are also quite constant along the sediment depth investigated, while Bacteria tend to decrease in the subsurface sediments. The abiotic (i.e. temperature, ammonium, pH) and trophic parameters (i.e. chlorophyll a) explain differentially the variations of bacterial and archaeal distribution, and raise interesting questions about the ecological significance of the microbial composition in this area.

Pang, W., Jin, Z., 2019. Revisiting methane absolute adsorption in organic nanopores from molecular simulation and Ono-Kondo lattice model. Fuel 235, 339-349.


Accurate characterization of methane absolute adsorption in shale plays an important role in estimation of gas-in-place and prediction of well productivity. Previously, methane adsorption in shale nanopores was considered as a single-layer structure. However, it has been shown that due to strong fluid-surface interactions, methane can form transition zone between the first adsorption layer and free gas phase. Such transition zone can negatively affect the accuracy of absolute adsorption estimation from excess adsorption, which is the mostly measured adsorption property in experiments. In this work, we use grand canonical Monte Carlo (GCMC) simulations to characterize the transition zone and propose a modified adsorption model. Based on the modified adsorption model, which can explicitly take into account the effect of transition zone, we use Ono-Kondo (OK) lattice model with multilayer structure to calculate the absolute adsorption in each layer and compare with GCMC simulations. The newly proposed OK model with multilayer structure only needs layer width as an input and calculates the density in each layer and subsequently the absolute adsorption by fitting the excess adsorption. While OK model can significantly reduce calculation time, discrepancy from GCMC simulation can be less than 6%. Our work should provide important insights into the accurate characterization of methane absolute adsorption from experimental measurement.



Seasonal variations in fluxes of isoprenoid glycerol dialkyl glycerol tetraethers (GDGTs) and the estimated temperatures based on TEX86 were examined in sinking particles collected using moored

sediment traps in the eastern Atlantic upwelling regions. In the equatorial Guinea Basin, GDGT fluxes show a correlation with opal fluxes, implying that GDGTs are mainly transported via aggregation with diatoms. The flux-weighted TEX86H temperatures derived from particles collected both at 853 m and 3921 m depth correspond to the water temperature (24.1 °C) of ca. 50 m depth, where nitrate concentration starts to increase. This suggests that nutrient concentrations may affect the depth habitat of Thaumarchaeota, thereby influencing the TEX86-derived water temperatures. In the coastal upwelling off Namibia, TEX86

H temperatures are similar to satellite-derived sea surface temperature (SST) during the warm season, but the record derived from the trap is delayed relative to the SST by approximately 26 days. Warm biases, however, occur during the cold season. Higher TEX86 values have been found within the oxygen minimum zones (OMZs) in the water column of coastal upwelling regions. Thus, contributions from GDGTs produced in OMZs might explain the warmer temperature estimates during the cold season in regions where OMZs are pronounced. This scenario could explain the observed warm bias off Namibia. We, therefore, suggest that in the eastern Atlantic upwelling systems, nutrient depth distribution and GDGTs produced in OMZs can be potential environmental factors influencing TEX86 in sinking particles. In paleoenvironmental records of TEX86, non-thermal signals have to be considered on regional scales.

Patil, A.A., Chiang, C.-K., Wen, C.-H., Peng, W.-P., 2018. Forced dried droplet method for MALDI sample preparation. Analytica Chimica Acta 1031, 128-133.


A forced dried droplet method (FDD) is developed to overcome the drawbacks of the conventional dried-droplet (DD) method for matrix assisted laser desorption/ionization (MALDI) sample preparation. The crystals produced by the DD method are heterogeneous and irregularly distributed, and thus many methods have tried to solve the problems. However, most of them spend more time or need additional instruments to generate homogeneous microcrystals. The FDD sample preparation method can produce uniform microcrystals with homogeneous size distribution in few minutes without additional instruments. Stirring the sample spot solution (an agitation process) with a pipette tip can change the crystal size distribution which is observed by the microscope. Mass spectrometric analysis shows that the smaller the crystal size is, the better the ion signal intensity is. The formation of microcrystals can be explained with the effective rate of secondary nucleation. The relative standard deviation (RSD) of the FDD method is ∼16% which is comparable to the two-layer (TL) method and is better than the DD method.

Patterson, M.O., McKay, R., Naish, T., Bostock, H.C., Dunbar, R., Ohneiser, C., Woodard, S.C., Wilson, G., Caballero-Gill, R., 2018. A southwest Pacific perspective on long-term global trends in Pliocene-Pleistocene stable isotope records. Paleoceanography and Paleoclimatology 33, 825-839.

https://doi.org/10.1029/2017PA003269

Abstract Continuous stable isotope records from marine sediment cores spanning the Pliocene have been used to assess the oceans' response to major perturbations in the climate system as the oceans play an integral role in regulating the global distribution of heat and gases. The Early to mid-Pliocene has previously been characterized as a time of relative warmth followed by Late Pliocene Southern Hemisphere cooling and bipolar glaciation at ~2.7 Ma. Previous studies have predominantly focused on the Atlantic and Equatorial Pacific Oceans. In this study, we extended the deep water benthic foraminifera stable isotope record from Ocean Drilling Program (ODP) Site 1123 in the southwest Pacific, back to the warm Early Pliocene. This is a high-latitude site at the gateway where the abyssal waters enter the Pacific Ocean and provides information about the connection between the Southern

Ocean and the Pacific. We identify a dichotomy between the deep southwest Pacific and South Atlantic δ13C records spanning the mid-Pliocene and suggest that this is most likely the result of variations in the relative contributions of Northern versus Southern Hemisphere deep waters to the different basins. At 3.6 Ma, δ13C values start to decrease; this is interpreted to represent alteration in preformed values as a result of increased remineralization of carbon caused by a reduction in deep ocean ventilation in the Southern Ocean. This is likely the consequence of a greater extent and seasonal duration of sea ice in the Southern Ocean from Antarctic Ice Sheet expansion and cooling.

Payan, F., de Klerk, A., 2018. Hydrogen transfer in asphaltenes and bitumen at 250 °C. Energy & Fuels.


Hydrogen transfer in asphaltenes and bitumen was studied at 250 °C. Use was made of dihydronaphthalene as probe molecule, which has both hydrogen donor and hydrogen acceptor properties. Tetralin and naphthalene, which are the products from hydrogen disproportionation of dihydronaphthalene, were unreactive as hydrogen donor and hydrogen acceptor in control reactions with asphaltenes. The asphaltenes fraction was a net hydrogen acceptor, whereas bitumen was a net hydrogen donor during prolonged conversion with dihydronaphthalene. The free radical content of asphaltenes and bitumen (of the order of 1018 spins/g in the feed) changed during thermal conversion and dihydronaphthalene affected these changes only to a minor extent. In the case of bitumen, there was a decrease in the free radical content of the product irrespective of whether dihydronaphthalene was present or not. Yet, despite the presence of free radicals in asphaltenes and bitumen, the reaction rate of dihydronaphthalene was suppressed compared to the self-reaction of dihydronaphthalene. Dihydronaphthalene reacted by molecule-induced homolysis to produce free radical intermediates; the initial reaction rate was around 1.6 × 10–3 mol·h–1·g–1. It was found that hydrogen donation by the free radical intermediates was faster than hydrogen abstraction, so that naphthalene was the most abundant product from self-reaction and that the heavier products formed by free radical addition were hydrogen enriched. Although formation of tetralin and naphthalene was thermodynamically favored, conversion was not equilibrium controlled and stoichiometric limitations were imposed by hydrogen disproportionation. Product selectivity during the self-reaction of dihydronaphthalene, and the decrease in reaction rate of dihydronaphthalene in the presence of free radical containing feed, both challenged the assumption that hydrogen abstraction by free radicals did not require activation energy. The work demonstrated that molecule-induced homolysis readily takes place at 250 °C and that oilsands derived asphaltenes and bitumen are reactive for hydrogen transfer at these conditions.

Pei, S., Wang, Y., Zhang, L., Huang, L., Cui, G., Zhang, P., Ren, S., 2018. An innovative nitrogen injection assisted in-situ conversion process for oil shale recovery: Mechanism and reservoir simulation study. Journal of Petroleum Science and Engineering 171, 507-515.


In-situ conversion process (ICP) can be an effective technique for the development of oil shale and ultra heavy oils, in which kerogen or heavy components will be cracked into light oils and gases via underground heating and pyrolysis, and the retorted oil can be recovered via conventional extraction techniques. Heating of targeted formation can be conducted using electrical heaters installed in vertical or horizontal wells, while a slow heating rate and lack of driving energy for oil production are the main issues of the conventional in-situ conversion process. In this study, an innovative nitrogen injection assisted in-situ conversion process (NAICP) was proposed to increase formation heating rate and improve oil production from oil shale. Reaction models of kerogen pyrolysis at elevated temperature were established, along with models for the evolution of porosity and permeability of oil

shale formation during the pyrolysis process. The performance of nitrogen injection on the effectiveness of the ICP was then investigated through reservoir numerical simulation. The simulation results show that additional nitrogen injection can improve the heating rate of the oil shale formation, enhance oil production and energy efficiency in comparison with the conventional ICPs, which can be attributed to enhanced heat convection, pressurization effect and gas driving mechanism. Nitrogen injection assisted in-situ conversion process can be a promising technique for the exploitation of oil shale.

Peischl, J., Eilerman, S.J., Neuman, J.A., Aikin, K.C., Gouw, J., Gilman, J.B., Herndon, S.C., Nadkarni, R., Trainer, M., Warneke, C., Ryerson, T.B., 2018. Quantifying methane and ethane emissions to the atmosphere from central and western U.S. oil and natural gas production regions. Journal of Geophysical Research: Atmospheres 123, 7725-7740.

https://doi.org/10.1029/2018JD028622

We present atmospheric measurements of methane (CH4) and ethane (C2H6) taken aboard a National Oceanic and Atmospheric Administration WP-3D research aircraft in 2015 over oil- and natural gas-producing regions of the central and western United States. We calculate emission rates from the horizontal flux of CH4 and C2H6 in the planetary boundary layer downwind of five of these oil- and gas-producing regions: the Bakken in North Dakota, the Barnett in Texas, the Denver Basin in Colorado, the Eagle Ford in Texas, and the Haynesville in Texas and Louisiana. In general, we find that the enhancement of C2H6 relative to CH4 in the atmosphere is similar to their relative abundances in locally produced natural gas. For the Bakken and Barnett regions, both absolute CH4 emissions and the percentage of produced natural gas emitted to the atmosphere are consistent with previous studies. The percentage of produced natural gas emitted to the atmosphere was lower than in previous studies in the Denver Basin and the Haynesville regions, which may be due to a decrease in drilling activity, an increase in emission controls, or some combination thereof. Finally, we provide the first estimates of basin-wide emissions from the Eagle Ford region using in situ airborne data and find C2H6

emissions to be greater than those from the Bakken region. Emissions from the Bakken and Eagle Ford regions combined account for 20% of anthropogenic C2H6 emissions in North America.

Pellerin, A., Antler, G., Røy, H., Findlay, A., Beulig, F., Scholze, C., Turchyn, A.V., Jørgensen, B.B., 2018. The sulfur cycle below the sulfate-methane transition of marine sediments. Geochimica et Cosmochimica Acta 239, 74-89.


The study of sulfate reduction below the sulfate-methane transition (SMT) in marine sediments requires strict precautions to avoid sulfate contamination from seawater sulfate or from sulfide oxidation during handling. We experimented with different methods of sampling porewater sulfate and found that modifications to our sampling procedure reduced the measured sulfate concentrations from hundreds of micromolar to ten micromolar or less. We here recommend some key modifications to porewater sampling to avoid contamination or oxidation artifacts, for example when measuring very low sulfate concentrations below the SMT of marine sediments. At three sites in Aarhus Bay, the sulfate concentrations below the SMT remained around ten micromolar. The calculated free energy change, ΔGr, available for sulfate reduction by such low concentrations is between −17.9 and −11.9 kJ mol−1 sulfate. This is near or below the energy yields that have previously been calculated for microbial sulfate reduction in marine sediments. The three sites are characterized by measurable and very different sulfate reduction rates depending on the depth and sediment age of the SMT. Our data show that sulfate is being consumed below the SMT in spite of the low sulfate concentrations.

As sulfate is not drawn down to even lower concentrations, it must be continually regenerated below the SMT, most likely by Fe(III)-driven sulfide oxidation concurrent with the sulfate reduction. We conclude that the low sub-SMT sulfate concentrations are in steady state between reduction and production and are thermodynamically controlled by the minimum ΔGr requirements by sulfate reducing bacteria while sulfate reduction rates are controlled by the rate of sulfide oxidation. This study deals with the general sampling of uncontaminated pore water and hints to a systemic problem with low levels of contamination in porewater induced by coring and pore water extraction. Below the SMT, this contamination could be detected but above the SMT it goes unnoticed. Low levels of contamination as observed in this study may affect other low concentration or redox-sensitive elements in pore water.

Peng, J., Qi, M., 2018. Poly(3-hexylthiophene) stationary phase for gas chromatographic separations of aliphatic and aromatic isomers. Journal of Chromatography A 1569, 186-192.


This work describes the investigation of utilizing a chain-typed thiophene-based π-conjugated polymer, i.e., poly(3-hexylthiophene) (P3HT), as the stationary phase for gas chromatography (GC). The P3HT column was statically prepared and investigated for its column efficiency, polarity, separation performance, repeatability and thermal stability. As a result, it showed moderate polarity and column efficiencies of 3260, 3310 and 3790 plates/m for 1-octanol, naphthalene and n-dodecane, respectively. As evidenced, it exhibited high-resolution performance for aliphatic and aromatic isomers, including those critical pairs such as phenanthrene/anthracene and p-/m-benzenediol isomers. Moreover, it displayed stronger retention for alkanes, alcohols and phenols in comparison to the polysiloxane stationary phase with close polarity. Also, the P3HT column had good repeatability and reproducibility with the RSD values less than 0.05% for run-to-run, 0.17–0.54% for day-to-day and 2.7–5.2% for column-to-column, and good thermal stability up to 260 °C. This work demonstrates the promising future of the thiophene-based polymer and its derivatives in separation science.

Peral, M., Daëron, M., Blamart, D., Bassinot, F., Dewilde, F., Smialkowski, N., Isguder, G., Bonnin, J., Jorissen, F., Kissel, C., Michel, E., Vázquez Riveiros, N., Waelbroeck, C., 2018. Updated calibration of the clumped isotope thermometer in planktonic and benthic foraminifera. Geochimica et Cosmochimica Acta 239, 1-16.


Accurate reconstruction of past ocean temperatures is of critical importance to paleoclimatology. Carbonate clumped isotope thermometry (“Δ47”) is a relatively recent technique based on the strong relationship between calcification temperature and the statistical excess of 13C–18O bonds in carbonates. Its application to foraminifera holds great scientific potential, particularly because Δ47 paleotemperature reconstructions do not require assumptions regarding the 18O composition of seawater. However there are still relatively few published observations investigating the potential influence of parameters such as salinity or foraminiferal size and species. We present a new calibration data set based on 234 replicate analyses of 9 planktonic and 2 benthic species of foraminifera collected from recent core-top sediments, with calcification temperatures ranging from −2 to 25 °C. We observe a strong relationship between Δ47 values and independent, oxygen-18 estimates of calcification temperatures:

Δ47 = 41.63 × 103/T2 + 0.2056

The formal precision of this regression (± 0.7–1.0 °C at 95 % confidence level) is much smaller than typical analytical errors. Our observations confirm the absence of significant species-specific biases or salinity effects. We also investigate potential foraminifer size effects between 200 and >560 μm in 6 species, and conclude that all size fractions from a given core-top location and species display statistically undistinguishable Δ47 values. These findings provide a robust foundation for future inter-laboratories comparisons and paleoceanographic applications.



This work analyses the distribution of volatile oil and other reservoir fluids in kerogen belonging to the gas condensate/volatile oil window. The kerogen models representing kerogen Type II-C contain pores in the range of micropores (diameter <2 nm) and mesopores (2 nm < diameter < 50 nm). A few of the micropores are isolated pores whereas the mesopores are connected in all spatial directions. Methane is observed to fill the pores while longer n-alkane chains transition from filling the pore to adsorbing onto the pore surface. The heavier components in the reservoir fluids adsorb onto the surface of the pore and can partially or completely clog the pore throats. As a general trend, the longer the alkane chain, the more preferentially the molecule adsorbs onto the pore surface. Additionally, the molecular simulations correctly capture the hydrophobic environment in which water molecules cluster together to form a droplet that resides in or close to a pore throat. Some molecules of carbon dioxide seem to preferentially adsorb onto either the kerogen internal surface or on the molecules of adsorbed heavier components, while the rest of the molecules diffuse into the kerogen body. This observation has not been previously reported to the best of our knowledge. Also the adsorption of the heavier species onto the pore walls significantly decreases the surface area available for adsorption of other species. This work underscores the significance of knowing fluid distributions to model primary recovery as well as secondary or tertiary recovery.



A study of petroleum inclusions based on ultraviolet fluorescence petrography, microspectrophotometry and biomarker analyses was carried out on samples from two wells of the onshore Lorena and the offshore Ubarana oilfields, Potiguar Basin, Brazil. This study aimed to evaluate the contribution and compositional variability of oils associated with different source rocks through the geochemical correlation of petroleum inclusions and crude oils. Three groups of inclusions were identified: (i) a group from the Lorena reservoir (Pendência Formation); (ii) a second from the Ubarana siliciclastic reservoir (Açu Formation); and (iii) a third from the carbonates adjacent to the Ubarana reservoir (Ponta do Mel Formation, PML). Fluorescence microspectrophotometry shows that the three groups of inclusions have different API gravity oils, variable proportion of saturate, aromatic, resins and asphaltenes and are not biodegraded. Moreover, Pendência and PML inclusions suggest multiple pulses of hydrocarbon migration, while Açu inclusions record a homogeneous pulse. Biomarkers indicate that the Pendência and Açu inclusion oils correlate with reservoir oil extracts. The Pendência inclusion oils are similar to the lacustrine oils of the Umbuzeiro graben (Pendência Formation), whereas the Açu inclusion oil displays closer biomarker signature to the Areia Branca trend of mixed oils (Alagamar Formation source rock).

However, the oil from fluid inclusions of the PML has characteristics of the Alagamar Formation lacustrine organic facies. The absence of mixed oils in the PML suggests an earlier lacustrine oil migration through the carbonate fractures prior to the main infill of mixed oils in the Ubarana oilfield.

Peterson, C.D., Lisiecki, L.E., 2018. Deglacial carbon cycle changes observed in a compilation of 127 benthic δ13C time series (20–6 ka). Climate of the Past 14, 1229-1252.

https://doi.org/10.5194/cp-14-1229-2018

We present a compilation of 127 time series δ13C records from Cibicides wuellerstorfi spanning the last deglaciation (20–6ka) which is well-suited for reconstructing large-scale carbon cycle changes, especially for comparison with isotope-enabled carbon cycle models. The age models for the δ13C records are derived from regional planktic radiocarbon compilations (Stern and Lisiecki 2014). The δ13C records were stacked in nine different regions and then combined using volume-weighted averages to create intermediate, deep, and global δ13C stacks. These benthic δ13C stacks are used to reconstruct changes in the size of the terrestrial biosphere and deep ocean carbon storage. The timing of change in global mean δ13C is interpreted to indicate terrestrial biosphere expansion from 19–6ka. The δ13C gradient between the intermediate and deep ocean, which we interpret as a proxy for deep ocean carbon storage, matches the pattern of atmospheric CO2 change observed in ice core records. The presence of signals associated with the terrestrial biosphere and atmospheric CO2 indicates that the compiled δ13C records have sufficient spatial coverage and time resolution to accurately reconstruct large-scale carbon cycle changes during the glacial termination.

Philibert, D.A., Lyons, D., Philibert, C., Tierney, K.B., 2019. Field-collected crude oil, weathered oil and dispersants differentially affect the early life stages of freshwater and saltwater fishes. Science of The Total Environment 647, 1148-1157.


The Deepwater Horizon (DWH) oil spill was the biggest in US history and released 3.19 million barrels of light crude oil into the Gulf of Mexico. In this study, we compared the toxicity of water accommodated fractions (WAFs) of naturally weathered crude oils, source oil, and source oil with dispersant mixtures and their effects on developing sheepshead minnow and zebrafish. Although a freshwater fish, zebrafish has been used as a model for marine oil spills owing to the molecular and genetic tools available and their amenability to lab care. Our study not only aimed to determine the effect of crude oil on early life stages of these two fish species, but also aimed to determine whether dissolved crude oil constituents were similar in fresh and saltwater, and if freshwater fish might be a suitable model to study marine spills. Weathering and dispersant had similar effects on WAF composition in both fresh and saltwater, except that the saltwater source oil + dispersant WAF had markedly higher PAH levels than the freshwater equivalent. WAF exposure differentially affected survival, as the LC50 values in %WAF for the zebrafish and sheepshead minnow exposures were 44.9% WAF (95% confidence interval (C.I.) 42.1–47.9) and 16.8% WAF (95% C.I. 13.7–20.5); respectively. Exposure increased heart rate of zebrafish embryos, whereas in sheepshead, source oil exposure had the opposite effect. WAF exposure altered mRNA expression of biotransformation makers, vitellogenin and neurodevelopment genes in both species. Muscle deformations were only found in oil-exposed zebrafish. This is one of the most comprehensive studies to date on crude oil toxicity, and highlights the species-specific differences in cardiotoxicity, estrogenic effects, biotransformation enzyme induction and potential neurotoxicity of crude oil exposure.

Picciani, N., Kerlin, J.R., Sierra, N., Swafford, A.J.M., Ramirez, M.D., Roberts, N.G., Cannon, J.T., Daly, M., Oakley, T.H., 2018. Prolific origination of eyes in cnidaria with co-option of non-visual opsins. Current Biology 28, 2413-2419.

http://dx.doi.org/10.1016/j.cub.2018.05.055

Animal eyes vary considerably in morphology and complexity and are thus ideal for understanding the evolution of complex biological traits [1]. While eyes evolved many times in bilaterian animals with elaborate nervous systems, image-forming and simpler eyes also exist in cnidarians, which are ancient non-bilaterians with neural nets and regions with condensed neurons to process information. How often eyes of varying complexity, including image-forming eyes, arose in animals with such simple neural circuitry remains obscure. Here, we produced large-scale phylogenies of Cnidaria and their photosensitive proteins and coupled them with an extensive literature search on eyes and light-sensing behavior to show that cnidarian eyes originated at least eight times, with complex, lensed-eyes having a history separate from other eye types. Compiled data show widespread light-sensing behavior in eyeless cnidarians, and comparative analyses support ancestors without eyes that already sensed light with dispersed photoreceptor cells. The history of expression of photoreceptive opsin proteins supports the inference of distinct eye origins via separate co-option of different non-visual opsin paralogs into eyes. Overall, our results show eyes evolved repeatedly from ancestral photoreceptor cells in non-bilaterian animals with simple nervous systems, co-opting existing precursors, similar to what occurred in Bilateria. Our study underscores the potential for multiple, evolutionarily distinct visual systems even in animals with simple nervous systems.

Pinto, J.S.S., Assis, L.M., Andrade, M.A., Lanças, F.M., 2018. Pressurized liquid extraction of Brazilian coal followed by the extracts characterization by gas chromatography coupled to mass spectrometry. Journal of Chromatographic Science 56, 761-769.

http://dx.doi.org/10.1093/chromsci/bmy051

This work reports a study on the use of Pressurized Liquid Extraction (PLE) for the selective extraction of organic compounds (aliphatic hydrocarbons – AHs, polycyclic aromatic hydrocarbons – PAHs and polycyclic aromatic compounds – PACs) from high-ash Brazilian coal. A homemade PLE system was built and solvents of different polarities (hexane, toluene and ethanol) were employed to extract the organic compounds from coal samples at a pressure of 10 MPa, under temperatures of 80°C and 200°C and extraction times up to 120 min. The selectivity of the extraction process was evaluated by a well-established methodology employed for the characterization of coal extracts (Preparative Liquid Chromatography – PLC 8). The fractions obtained in the PLC-8 method were dried and, after, quantified by gravimetry. Results showed that the proposed method of extraction was selective for the extraction of AHs using hexane at the temperature of 80°C and for the extraction of PAHs at 200°C. Additionally, the method showed to be selective for the extraction of PACs using ethanol at both studied temperatures. The AHs and PAHs fractions were also analyzed by GC–MS, showing that the first was composed mainly by low molecular weight compounds (<31 carbons) while the second by pyrenes, fluoranthenes, crysenes, benzopyrenes, perylenes and benzofluoranthenes. The present method showed to be a powerful tool for selective extraction of organic compounds from coal samples with simplicity, low quantity of solvent and filling other the requirements to be considered a greener method of extraction.

Ponomareva, E.V., Burshtein, L.M., Kontorovich, A.E., Kostyreva, E.A., 2018. Organic carbon distribution in the Bazhenov horizon rocks of the western Siberian megabasin. Doklady Earth Sciences 481, 918-921.

https://doi.org/10.1134/S1028334X18070176

The distribution of organic carbon in the Bazhenov horizon rocks of the western Siberian sedimentary basin is investigated. The organic carbon concentration in rocks is estimated by the results of core analyses (4094 core analyses) and by the calculations of the core-log data correlations (48 500 measurements) according to the data of radiation and electrical loggings. The average content of organic carbon in the rocks of the Bazhenov and Tutleim (lower subformation) formation is 7.7%. The map of organic carbon concentrations in the sedimentary rocks of the basin is constructed. In the basin, Corg is distributed asymmetrically. The region of maximum Corg concentrations occupies the southwestern part of the internal area of the sedimentary basin. Silicites and biogene silica-enriched mixtites are enriched with organic matter most of all. Original Russian Text © E.V. Ponomareva, L.M. Burshtein, A.E. Kontorovich, E.A. Kostyreva, 2018, published in Doklady Akademii Nauk, 2018, Vol. 481, No. 2.

Pontefract, A., Hachey, J., Zuber, M.T., Ruvkun, G., Carr, C.E., 2018. Sequencing nothing: Exploring failure modes of nanopore sensing and implications for life detection. Life Sciences in Space Research 18, 80-86.


The detection of extant life is a major focus of many planned future planetary missions, a current challenge of which is the ability to target biomarkers capable of providing unambiguous evidence of life. DNA sequencing is increasingly recognized as a powerful tool for life detection for planetary exploration missions; beyond use of sequence information to determine the origins of the sample (e.g., extant life or forward contamination), recent advances in the field have enabled interrogation of single molecules, with or without amplification. The focus of this work is on failure modes, specifically the issues encountered when there is no-to-low input DNA into a sequencing device, and the potential for the generation of sequencing artifacts that could be interpreted as a false positive. Using Oxford Nanopore Technologies (ONT) MinION, we assess whether single molecule sequencing, involving no amplification, generates noise signals that could be misinterpreted in the context of a planetary exploration mission, and also whether the ability of the instrument to handle these types of situations could make it feasible for clean room monitoring. Utilizing quality score filtering techniques in place at the time of this experiment, runs containing only initial flowcell chemistry and/or library reagents generated 5 passing reads out of a total of 3568 measured reads, and contained estimated sequences with low complexity that did not map to the NCBI database. The noise characteristics in all instances suggest that quality thresholds were appropriately chosen by ONT: new chemistry and basecalling workflows have shown further suppression of noise sources, which completely mitigate the generation of spurious reads.

Purswani, P., Karpyn, Z.T., 2019. Laboratory investigation of chemical mechanisms driving oil recovery from oil-wet carbonate rocks. Fuel 235, 406-415.


The purpose of this work is twofold; to improve current understanding of the oil recovery mechanism behind chemically tuned waterflooding in oil-wet carbonate rocks, and to propose a set of governing chemical reactions consistent with this mechanism. For this, a series of waterflood experiments were conducted at 90 °C with synthetic seawater type brine solutions with varying compositions of potential determining ions (Ca2+, Mg2+, and SO4

2−). Characterization techniques like zeta potential, contact angle, and trace element analysis were implemented to account for the ionic interactions

taking place among the rock, the brine solution, and the crude oil. Additionally, relative permeabilities were estimated using the Brooks and Corey model where the wettability exponents were tuned against the experimental fractional flow data. Zeta potential measurements highlight the affinity of Mg2+, Ca2+, and SO4

2− ions toward the rock surface in chemically tuned brines where an increase in the magnitude of zeta potential was observed corresponding to the increase in the concentration of each of these ions in the suspension. Oil recovery measurements show an increase for all chemically tuned brines when compared to plain seawater injection. Relative permeability estimations and contact angle measurements show corresponding trends of increasing water–wetness, suggesting the alteration of wettability. Maximum recovery of ∼76% original oil in place (OOIP) was observed for the brine with increased Mg2+ ion concentration due to higher activity of Mg2+ ions and their ability to replace Ca2+ ions from the rock surface. A lower recovery of ∼64% OOIP was seen for the brine with increased Ca2+ ion concentration due to lower activity of Ca2+ ions as opposed to Mg2+ ions. Further lower recovery of ∼59% OOIP was seen for the brine with increased SO4

2− ion concentration due to the increased precipitation of these ions on the rock surface. These chemical reactions including salt precipitation, crude oil desorption/solubilization, and mineral dissolution were confirmed through ionic analysis of the effluent brine during each waterflooding experiment. The presented experimental results and the proposed sequence of chemical reactions can be used for the development of an appropriate reaction model for predicting oil recovery via wettability alteration.

Qi, C., Li, C., Gabbott, S.E., Ma, X., Xie, L., Deng, W., Jin, C., Hou, X.-G., 2018. Influence of redox conditions on animal distribution and soft-bodied fossil preservation of the Lower Cambrian Chengjiang biota. Palaeogeography, Palaeoclimatology, Palaeoecology 507, 180-187.


The exceptionally preserved Chengjiang Biota (Yunnan, China) is significant for understanding the rapid development of complex animal-rich ecosystems during the evolutionary radiation of the Cambrian. However, the ecological signal provided by the fossils captured in this deposit may not reflect accurately the in-life community, with transport and decay of carcasses being the principal processes responsible for potential modification. The principal fossil-bearing interval (Maotianshan Shale Member, Yu'anshan Formation) is comprised of claystones of two distinct depositional origins: the “background” beds represent slow hemipelagic deposition into deep waters, while the “event” beds represent distal turbidites or storm-generated beds. Each bed type has a distinct fossil assemblage and preservation mode underscoring the importance of interpreting the palaeoenvironment of each bed type. Here, we interpret palaeo-redox conditions for both the background beds and the event beds by conducting a systematic geochemical study using iron speciation, δ34Spy, δ13Ccarb,δ13CTOC and molybdenum abundance. These data are from the most complete core recovered from the Chengjiang fossiliferous units and allow us to distinguish redox conditions where the animals lived, and where they were buried and exceptionally preserved. Our results demonstrate that background beds were dominated by dysoxic conditions; here, a diverse sponge community tolerant of low-oxygen conditions lived. In contrast, the shallower shelf and offshore-transitional environments, where event beds were sourced, were almost persistently oxic, and it was here where the diverse Chengjiang Biota flourished. Thus, the Chengjiang sediments record two distinct palaeocommunities within the background and the event beds. The contrasting redox conditions in close spatial proximity likely facilitated the soft-bodied fossil preservation. Our findings provide a valuable case study in the necessity to understand ecological composition and exceptional preservation informed by environmental context.

Qi, Y., Hann, W., Subagyono, D.J.N., Fei, Y., Marshall, M., Jackson, W.R., Patti, A.F., Chaffee, A.L., 2018. Characterisation of the products of low temperature pyrolysis of Victorian brown coal in a semi-continuous/flow through system. Fuel 234, 1422-1430.


Two Victorian brown coal samples, a run-of-mine Loy Yang coal (LY) and a Loy Yang light lithotype (LL), were subjected to pyrolysis at 420–460 °C and 330–460 °C, respectively, under a continuous nitrogen flow. The process produced condensed products in two phases, oil and aqueous, as well as solid residue and gaseous products. An increase in the condensed product yields with increasing temperature was observed for both coals, with LL achieving higher yield than LY at a given temperature (e.g. 26.3 wt% vs 19.5 wt% at 460 °C). The condensed products were characterized by 1H and 13C NMR as well as GC–MS. Abundant triterpenoid polycyclics and aliphatic hydrocarbons were found in the oils from both coals produced at lower temperatures, whilst the yield of aromatics significantly increased with increasing pyrolysis temperature. Analyses of the solid residues by FTIR, solid state 13C NMR and flash pyrolysis GC–MS (Py-GC–MS) also revealed an increasing aromaticity of the residues at higher temperatures. Py-GC–MS analysis identified compound groups released by flash pyrolysis at 650 °C and the results were found to correspond to those of GC–MS for the oil.

Qian, K., Yang, Z., Zhang, F., Yang, B., Dasgupta, P.K., 2018. Low-bleed silica-based stationary phase for hydrophilic interaction liquid chromatography. Analytical Chemistry 90, 8750-8755.


Bleeding of hydrophilic interaction liquid chromatographic (HILIC) phases is a major problem. A hydrophobic silica surface exhibits low bleeding but does not behave as a HILIC phase. A hydrophilic coating, such as that of poly(vinyl alcohol) (PVA) on a hydrophobic particle should result in a low-bleed hydrophilic phase. However, a silica particle functionalized in a hydrophobic manner is not wetted by PVA and cannot be coated with it. Coating with PVA becomes possible if one region of the hydrophobic functionality is polar. We describe a low-bleed HILIC stationary phase, PVA-coated benzylthioethyl-silica. The benzyl groups shield the silica from water erosion, while the thiol group provides sufficient local polarity for PVA to wet the material. The new stationary phase demonstrated good chromatographic performance and typical HILIC retention behavior. The measured silica concentration in the effluent was ∼80-fold lower than that from a bare silica column. The new stationary phase exhibited a lower background level, lower background noise, and lower background drift under gradient conditions than benchmark commercial columns.

Qin, S.-B., Fan, Y.-H., Mou, X.-X., Li, X.-S., Qi, S.-H., 2018. Preparation of phenyl-modified magnetic silica as a selective magnetic solid-phase extraction adsorbent for polycyclic aromatic hydrocarbons in soils. Journal of Chromatography A 1568, 29-37.


Accurate analysis of polycyclic aromatic hydrocarbons (PAHs) in soils remains a challenge due to the complexity of sample matrices. In this paper, phenyl-modified magnetic mesoporous silica ( Fe3O4@mSiO2-Ph-PTSA) was synthesized with p-toluenesulfonic acid (PTSA) as the catalyst and used as a selective adsorbent for the clean-up of PAHs extracted from soils. The material prepared without PTSA as the catalyst ( Fe3O4@mSiO2-Ph) was synthesized for comparison. The synthesized materials were first systematically characterized and evaluated. It was found that the grafting amount

of the phenyl group onto Fe3O4@mSiO2-Ph-PTSA was higher than that onto Fe3O4@mSiO2-Ph. The extraction efficiency obtained by extracting PAHs from the extracted soil matrix solution demonstrated that Fe3O4@mSiO2-Ph-PTSA possessed a much higher extraction efficiency than that of Fe3O4@mSiO2-Ph, which can be attributed to the greater amount of phenyl groups grafted on Fe3O4@mSiO2 in the presence of the PTSA catalyst. Moreover, contrast experiments showed that Fe3O4@mSiO2-Ph-PTSA displayed higher selectivity towards PAHs than towards n-alkanes and that the π-π interaction played a key role in the adsorption process. In the presence of the soil extract matrix, the parameters affecting the extraction efficiency of Fe3O4@mSiO2-Ph-PTSA for PAHs were optimized. Under the optimal conditions, coupled with pressurized liquid extraction and gas chromatograph-mass spectrometer, the proposed method for the determination of PAHs in soils was linear in the range of 5–500 ng g−1, and the correlation coefficients (R) ranged between 0.9994 and 0.9999. The limits of detection (LODs) and limits of quantification (LOQs), which were based on signal-to-noise ratios of 3 and 10, respectively, were in the range of 0.07–0.41 ng g−1 and 0.24–1.37 ng g−1. The developed method displayed a better clean-up effect than that for silica gel column method, and the matrix effect markedly decreased compared to that of the uncleaned condition. Finally, the developed method was successfully applied for the detection of PAHs in environmental soils, and the data were consistent with the results obtained by the silica gel column method. The analytical results were also consistent with those for the real environment.

Qin, S., Luo, P., Wang, T., Wang, L., Ma, K., 2018. Discovery and geological significance of high quality hydrocarbon source rocks in interglacial of Neoproterozoic in the eastern part of the southern margin of North China. Journal of Natural Gas Geoscience 3, 73-79.


A conglomerate of glacial deposits from Neoproterozoic Sinian is generally developed in the southern margin of the North China Plate. However, whether the hydrocarbon source rock exists in a conglomerate of glacial deposits is still undeterminable as it has not been studied previously. The developmental characteristics of the conglomerate were systematically observed and measured. The conglomerate was subsequently divided into four sets, and the gray-black shale was discovered in between them. The said shale has the thickness of 36 m, 46 m, and 7 m, respectively from top to bottom. The study presents the highly-abundant organic matter in the shale, which belong to the high-quality hydrocarbon source rock. The organic matters are derived from lower organisms. The discovery of thick and high-quality hydrocarbon source rocks in conglomerates opens up new exploration areas for conventional natural gas, as well as provides a powerful basis for shale gas exploration. The dropstones that appeared in hydrocarbon source rocks and conglomerates are cogent evidence of glaciation. The findings provide an important guiding significance for the genesis of the conglomerate.

Qin, S., Zhang, Y., Zhao, C., Zhou, Z., 2018. Geochemical evidence for in situ accumulation of tight gas in the Xujiahe Formation coal measures in the central Sichuan Basin, China. International Journal of Coal Geology 196, 173-184.


The study of accumulation mechanisms of tight gas has attracted much attention in recent years. One of the focuses is whether natural gas can migrate on a large scale in tight reservoirs. In this work, geochemical parameters (such as C1/C1+, C1/(C2+ C3), C1+, δ13C1, δ13C2, iC4/nC4, iC5/nC5) of the tight gas reservoirs in the central Sichuan Basin, China have been studied to characterize the accumulation mechanisms in these fields. Results show that the tight gas accumulation in the Xujiahe Formation in

the central Sichuan is in situ, and natural gas has not experienced large-scale migration. In gases from the central Sichuan Basin, δ13C1 ranges from −44.1‰ to −37.1‰ with an average of −40.1‰, and C1/C1+ ranges from 0.80 to 0.97 with an average of 0.91. While in the gases from the western Sichuan Basin, δ13C1 is between −35.5‰ and − 30‰ with an average of −32.2‰, and C1/C1+ ranges from 0.95to 0.99with an average of 0.98. Based on geochemical indicators of natural gas, the gases of Xujiahe Formation in the Central Sichuan Basin originated from the local coal measures of the Xujiahe Formation in horizontal direction with little contribution from the western Sichuan. In central Sichuan Basin, there is also no horizontal migration of natural gas in the same formation between adjacent gas fields. Vertically, the Xujiahe Formation is an independent gas generating system and has no relationship with the underlying Mid-Lower Triassic formations and the Jurassic natural gas formation above it. The δ13C2of Xujiahe Formation in central Sichuan ranges from −28.3‰ to −25.9‰, with an average of −27.5‰. However, the δ13C2 of Lower Jurassic above Xujiahe Formation ranges from −36.8‰ to −30.5‰, with an average of −33.0‰. Under the Xujiahe Formation, the δ13C2

in Leikoupo Formation ranges from −35.5‰ to −32.1‰, with an average of −33.1‰, and in Jialingjiang Formation ranges from −34.6‰ to −33.2‰, with an average of −33.8‰. There is also a clear distinction in the geochemical characteristics of natural gas between the upper and lower gas reservoirs in the Xujiahe Formation, indicating that there is no obvious vertical migration of natural gas. Geochemical evidence shows that there is no large-scale gas migration in the Xujiahe Formation. The tight gas is generated in situ and accumulated in the formation in the central Sichuan Basin.

Qu, H., Zhou, Z., Zhang, YunFeng, Chen, W., Zhang, Z., Luo, X., Ma, C., Tan, F., Zhu, Y., 2018. Research progress of porosity in microbial carbonates. Acta Sedimentologica Sinica 86, 651-663.


Microbial carbonates are not only important sedimentary records for paleo environments, paleoclimate and geological events, but also significant hydrocarbon reservoirs. Physiological characteristics of diverse microbial communities in part control the formation and preservation of primary pores, microbial depositional fabrics in various scales affect the diameter and distribution of pores. Combination patterns of microbial carbonates and associated facies have a great impact on usefulness and scale of pores. Different sedimentary processes and depositional environments of microbial carbonates affect sequences and degrees of cementation and dissolution during meteoric diagenesis, resulting in heterogeneity of pores. Microbe-related diageneses such as dolomitization, cementation, and karstification may form primary pores, protect residual pores and form secondary pores during various stages. Pore diameters of microbial carbonates are in range from nanometer-submicron level to centimeter and even meter level, which may correspond to multi-scale sedimentary structures to some extent. Therefore, it's necessary to analyze and characterize samples in various scales. In addition, the combination of geology and geophysics should be enhanced, being an important way to facilitate research of hydrocarbon reservoirs of microbial carbonates also benefit for the exploration and exploitation of oil and gas resources.

Qu, Y., Lepland, A., van Zuilen, M.A., Whitehouse, M., Črne, A.E., Fallick, A.E., 2018. Sample-scale carbon isotopic variability and diverse biomass in the Paleoproterozoic Zaonega Formation, Russia. Precambrian Research 315, 222-231.


The stratigraphic record of organic matter in the c. 1.97 Ga Zaonega Formation (ZF), Onega Basin, northwestern Russia, exhibits a distinct negative δ13C excursion (δ13Corg from −25 to −40‰ VPDB), which was previously interpreted either to reflect a disturbance in the global carbon cycle after the

Great Oxidation Event, or to have been caused by an increase in basinal methanotrophic activity. In order to assess the nature of primary biomass and the effects of post-depositional alteration, we here report the sample-scale carbon isotopic characteristics of organic matter in two drill cores from the ZF, covering 500 m of stratigraphy, by using secondary ion mass spectrometry (SIMS). The results confirm that the organic matter has to a large extent preserved the primary isotopic signatures, whereas secondary effects are limited (<4‰). The sample-scale isotopic heterogeneity, defined as the difference between the maximum and minimum δ13C values obtained by SIMS from every individual sample, increases from typically <5‰ in the lower part of stratigraphy to systematically larger values (up to 11‰) in the upper part, which coincides with the decreasing trend of δ13Corg of bulk samples from −25 to −40‰. Samples with either relatively high (c. −25‰) or low (c. −40‰) δ13Corg values have small sample-scale isotopic heterogeneities, while samples with intermediate δ13Corg values (between −25 and −40‰) have significantly larger heterogeneities. These observations imply the co-existence of photoautotrophic and methanotrophic biomass during deposition of the upper part of the stratigraphy. Our study provides insight into the carbon isotopic characteristics of organic matter and suggests that the negative excursion of δ13Corg in the ZF is induced by a methanotrophic microbial ecosystem sustained by seepage of thermogenic methane during the deposition of the ZF and contemporaneous igneous activities.

Rahman, M.M., Liu, R., Cai, J., 2018. Catalytic fast pyrolysis of biomass over zeolites for high quality bio-oil – A review. Fuel Processing Technology 180, 32-46.


Catalytic fast pyrolysis is a prominent technology for yielding high quality bio-oil and chemicals from lignocellulosic biomass while the application of catalyst has been a hotspot for being capable to deoxygenate bio-oil and enhance its fuel properties. The fundamental reaction pathways in catalytic fast pyrolysis and potential routes of bio-oil and chemicals production from three major individual components are discussed at the early section of the review. The effect and potentiality of solid acid catalyst mainly zeolites, biomass particle size and catalyst loading ratio on the yield and quality of bio-oil are then emphasized. In addition, the lumped kinetic model and distributed activation energy model (DAEM), used to predict the thermal behavior of biomass components and energy calculation in catalytic pyrolysis are described. The recent advances in the understanding of catalytic co-pyrolysis of lignocellulosic biomass with hydrogen rich co-feeder from different sources are also presented. The progress with technical difficulties in catalytic pyrolysis is pointed out having an intention to produce high quality bio-oil. Finally, some challenges and perspectives of improving bio-oil quality through catalytic fast pyrolysis that will be significant approach in the future research work are presented.

Rainsley, E., Menviel, L., Fogwill, C.J., Turney, C.S.M., Hughes, A.L.C., Rood, D.H., 2018. Greenland ice mass loss during the Younger Dryas driven by Atlantic Meridional Overturning Circulation feedbacks. Scientific Reports 8, Article 11307.

https://doi.org/10.1038/s41598-018-29226-8

Understanding feedbacks between the Greenland Ice Sheet (GrIS) and the Atlantic Meridional Overturning Circulation (AMOC) is crucial for reducing uncertainties over future sea level and ocean circulation change. Reconstructing past GrIS dynamics can extend the observational record and elucidate mechanisms that operate on multi-decadal timescales. We report a highly-constrained last glacial vertical profile of cosmogenic isotope exposure ages from Sermilik Fjord, a marine-terminating ice stream in the southeast sector of the GrIS. Our reconstruction reveals substantial ice-

mass loss throughout the Younger Dryas (12.9-11.7 ka), a period of marked atmospheric and sea-surface cooling. Earth-system modelling reveals that southern GrIS marginal melt was likely driven by strengthening of the Irminger Current at depth due to a weakening of the AMOC during the Younger Dryas. This change in North Atlantic circulation appears to have drawn warm subsurface waters to southeast Greenland despite markedly cooler sea surface temperatures, enhancing thermal erosion at the grounding lines of palaeo ice-streams, supporting interpretation of regional marine-sediment cores. Given current rates of GrIS meltwater input into the North Atlantic and the vulnerability of major ice streams to water temperature changes at the grounding line, this mechanism has important implications for future AMOC changes and northern hemisphere heat transport.

Raiswell, R., Hardisty, D.S., Lyons, T.W., Canfield, D.E., Owens, J.D., Planavsky, N.J., Poulton, S.W., Reinhard, C.T., 2018. The iron paleoredox proxies: A guide to the pitfalls, problems and proper practice. American Journal of Science 318, 491-526.


Oceanic anoxia—including euxinic settings defined by the presence of water column hydrogen sulfide (H2S)—is minor in the ocean today. Such conditions, however, were common or even dominant in the past, particularly during the Precambrian and Phanerozoic oceanic anoxic events. The latter are associated with massive petroleum and mineral reserves and many of the major extinction events in the paleontological record. Our ability to recognize ancient oxygen deficiencies relies strongly on paleontological data viewed in combination with geochemical tracers, and geochemistry is typically our only window onto ancient marine redox during the Precambrian when diagnostic skeletal and behaviorial traces of oxygen-dependent animals are mostly missing. So far no approach has gained wider acceptance than the iron proxies, which rely generally on quantification of the extent to which reactive iron (as oxides principally) is converted to pyrite. The promise of these approaches lies in part with the relative ease of measurement, but it is this ease and the corresponding widespread use that has also led to misuses.

Much of the recent confidence in the iron paleoredox proxies lies with sophisticated deconstruction of the reactive Fe pool via mineral-calibrated wet chemical speciation. These validations and calibrations, mostly in the modern ocean, expose the challenges, while at the same time opening other doors of opportunity as the catalog of controlling factors extends beyond water column redox to include sedimentation rate, sedimentary Fe remobilization, signals of oscillatory redox, and hydrothermal versus other primary Fe inputs to the ocean, among other factors. Also key is a deep understanding of the limitations imposed—or at least the due diligence required—as linked to mineral transformations during burial and metamorphism. This review seeks to highlight many of the key issues, including appropriate sample choices, as a roadmap for those keen to apply Fe proxies in their studies of ancient oceans and their relationships to co-evolving life. Among the critical messages to take away is the value of robust Fe-based measures of local redox that, when combined with elemental mass balances and isotopic proxies dependent on those local conditions, can shed light on the global redox state of the oceans through time and related implications for the history of life on Earth.



Sea surface temperature determinations based on marine sedimentary C37 alkenone distributions have provided a wealth of data for paleoclimatic studies, including those performed at high resolution. The success of this approach results from several characteristics of alkenone compounds, e.g. their geochemical properties (such as unequivocal synthesis by certain widespread haptophyte algae, plus chemical stability/preservation of the original alkenone distributions during sedimentation), and their analytical properties (such as fast clean up procedures using alkaline hydrolysis of sediment extracts, followed by robust instrumental methods allowing large scale sample processing). Here we show that, in sediments under the influence of continental inputs, coelution of these compounds with cholest-5-enyl 3β-undecenyl ether and 24-methylcholesta-5,22-dienyl 3β-undecenyl ether deviate the SST measurements despite alkaline hydrolysis. Here, we report a new high performance liquid chromatrography fractionation method which eliminates these interfering compounds and gathers all the alkenones into a single fraction. These fractions can then be analysed by gas chromatography as in the initial approach, providing large amounts of data as required in high resolution studies.

Ramírez-González, P.V., Zavala Arriaga, M.M., Escobar-Barrios, V.A., 2018. A rapid method for interfacial tension calculation between rock plug and crude oil based on contact angles, application for EOR. Petroleum Science and Technology 36, 1242-1249.

https://doi.org/10.1080/10916466.2018.1465975

Interfacial tension and contact angle are two specific important parameters to take decisions for enhanced oil recovery, for instance, proper chemicals to use for surface tension reduction, expected wettability of solids, interaction between crude oil and rock. For this purpose, the article presents a method for easy calculation of the solid-liquid interfacial tension based on contact angle measurements applying Neumann's correlation and Young's equation. The main idea stands on the calculation of the rock parameters, like wettability, with known substances and extend these results to crude oils. It was possible, based on the results obtained, to establish a relationship between solid-liquid interfacial tension and contact angle for the crude oil - rock system, which can definitively be used for the calculation of interfacial tension of any other fluid spread out on the same kind of rock. A linear regression was obtained with an accuracy as good as R2 = 0.9989. Viscosity as a function of contact angle could also be obtained for the studied crude oils in the same kind of rock.

Ranjan, S., Todd, Z.R., Sutherland, J.D., Sasselov, D.D., 2018. Sulfidic anion concentrations on early Earth for surficial origins-of-life chemistry. Astrobiology 18, 1023-1040.


A key challenge in origin-of-life studies is understanding the environmental conditions on early Earth under which abiogenesis occurred. While some constraints do exist (e.g., zircon evidence for surface liquid water), relatively few constraints exist on the abundances of trace chemical species, which are relevant to assessing the plausibility and guiding the development of postulated prebiotic chemical pathways which depend on these species. In this work, we combine literature photochemistry models with simple equilibrium chemistry calculations to place constraints on the plausible range of concentrations of sulfidic anions (HS−, HSO3

−, SO32−) available in surficial aquatic reservoirs on early

Earth due to outgassing of SO2 and H2S and their dissolution into small shallow surface water reservoirs like lakes. We find that this mechanism could have supplied prebiotically relevant levels of SO2-derived anions, but not H2S-derived anions. Radiative transfer modeling suggests UV light would have remained abundant on the planet surface for all but the largest volcanic explosions. We apply our results to the case study of the proposed prebiotic reaction network of Patel et al. (2015) and discuss the implications for improving its prebiotic plausibility. In general, epochs of moderately

high volcanism could have been especially conducive to cyanosulfidic prebiotic chemistry. Our work can be similarly applied to assess and improve the prebiotic plausibility of other postulated surficial prebiotic chemistries that are sensitive to sulfidic anions, and our methods adapted to study other atmospherically derived trace species.

Ratnayake, A.S., Kularathne, C.W., Sampei, Y., 2018. Assessment of hydrocarbon generation potential and thermal maturity of the offshore Mannar Basin, Sri Lanka. Journal of Petroleum Exploration and Production Technology 8, 641-654.

https://doi.org/10.1007/s13202-017-0408-1

The Mannar Basin is an under-explored offshore sedimentary basin in terms of petroleum geology. The Cretaceous to Paleogene cutting samples were collected in three offshore exploration wells (i.e. the Dorado North, Dorado and Barracuda) in the Mannar Basin. In this study, kerogen type, quantity and thermal maturity of sedimentary organic matter were ascertained using Rock–Eval pyrolysis and vitrinite reflectance analyses. In addition, 1-D basin modelling was used to analyse the timing of hydrocarbon generation in the Mannar Basin. Total organic carbon (TOC) contents and total hydrocarbon potential are higher in the Cretaceous calcareous mudstones than in the Paleogene calcareous silty/sandy mudstones. TOC contents show a negative correlation with oxygen index. Hydrogen index and oxygen index values range from 77 to 785 mg HC/g TOC and from 25 to 165 mg HC/g TOC, respectively. Organic matters were identified as mixed Type II–III and Type III kerogen. Maturity expressed in term of Tmax and vitrinite reflectance range from 332 to 456 °C and from 0.26 to 1.49%, respectively. It indicates both immature and mature sediments. In general, maturity values are relatively high in the Late Cretaceous sediments (Tmax, from 332 to 456 °C, average = 423 °C ± 25) compared to the Paleogene sediments (Tmax, from 388 to 431 °C, average 419 °C ± 10). Geochemical proxies show that oil and gas prone (Type II–III) and gas prone (Type III) kerogen-rich Late Cretaceous sediments of the Dorado and Barracuda wells have principally achieved maturity levels for oil window. Therefore, it suggests incomplete thermal conversion for the wet gas generation in the northeast part of the Mannar Basin. In the 1-D basin modelling, the maximum hydrocarbon generation was observed during the Neogene Period in the Late Cretaceous sediments of the deeper Barracuda well.

Ray, A.E., Connon, S.A., Neal, A.L., Fujita, Y., Cummings, D.E., Ingram, J.C., Magnuson, T.S., 2018. Metal transformation by a novel Pelosinus isolate from a subsurface environment. Frontiers in Microbiology 9, 1689. doi: 10.3389/fmicb.2018.01689.


The capability of microorganisms to alter metal speciation offers potential for the development of new strategies for immobilization of toxic metals in the environment. A metal-reducing microbe, “Pelosinus lilae” strain UFO1, was isolated under strictly anaerobic conditions from an Fe(III)-reducing enrichment established with uncontaminated soil from the Department of Energy Oak Ridge Field Research Center, Tennessee. “P. lilae” UFO1 is a rod-shaped, spore-forming, and Gram-variable anaerobe with a fermentative metabolism. It is capable of reducing the humic acid analog anthraquinone-2,6-disulfonate (AQDS) using a variety of fermentable substrates and H2. Reduction of Fe(III)-nitrilotriacetic acid occurred in the presence of lactate as carbon and electron donor. Ferrihydrite was not reduced in the absence of AQDS. Nearly complete reduction of 1, 3, and 5 ppm Cr(VI) occurred within 24 h in suspensions containing 108 cells mL−1 when provided with 10 mM lactate; when 1 mM AQDS was added, 3 and 5 ppm Cr(VI) were reduced to 0.1 ppm within 2 h. Strain UFO1 is a novel species within the bacterial genus Pelosinus, having 98.16% 16S rRNA gene

sequence similarity with the most closely related described species, Pelosinus fermentans R7T. The G+C content of the genomic DNA was 38 mol%, and DNA-DNA hybridization of “P. lilae” UFO1 against P. fermentans R7T indicated an average 16.8% DNA-DNA similarity. The unique phylogenetic, physiologic, and metal-transforming characteristics of “P. lilae” UFO1 reveal it is a novel isolate of the described genus Pelosinus.

Ren, B., 2018. Local capillary trapping in carbon sequestration: Parametric study and implications for leakage assessment. International Journal of Greenhouse Gas Control 78, 135-147.


Local capillary trapping (LCT) is the trapping of CO2 by local capillary barriers. It occurs during buoyancy-driven migration of bulk phase CO2 within a saline aquifer exhibiting spatially varying properties (permeability and capillary entry pressure). The benefit of LCT, in the context of CO2 sequestration, is that local capillary trapped CO2 is not susceptible to leakage through failed seals. However, it is unclear how the petrophsyical/geological properties and flow dynamics influence LCT. Thus, the objective of this work is to evaluate the degree to which potential local capillary traps are filled and quantify the extent of immobilization persisting after loss of seal integrity. This paper presents a systematic and thorough study of the influential parameters of LCT. Fine-scale capillary pressure fields are generated by using geostatistical permeability realizations and applying the Leverett j-function. Multiple factors are examined, including injection rate, anisotropy, formation dip, aquifer types, residual gas saturation, and capillary hysteresis. Leakage representative of wellbore failure is simulated, and LCT after leakage is evaluated and compared to other trapping mechanisms. The results show that local capillary traps in the near-well region can be fully filled during injection. Moreover, they remain filled after post-injection buoyancy-driven flow ends. The filling efficiency of local capillary traps increases with the decrease in gravity number (ratio of buoyant force over viscous force). As a result, maximizing LCT in carbon sequestration in porous reservoirs may be achievable with the implementation of appropriate injection strategies.

Rhino, K., Loisy, C., Cerepi, A., Garcia, B., Rouchon, V., Khamlichi, A.E., Noirez, S., 2018. Characterization and quantification of a CO2 and CH4 leakage experiment from a well into the carbonate vadose zone. International Journal of Greenhouse Gas Control 77, 55-69.


An ultra-diffusive leakage experiment was performed on the pilot site of Saint-Emilion near Bordeaux in France. It consisted in the injection of 85% CO2 and 5% of each He, Kr and CH4 in a vertical well with a very low injection pressure. This study allowed the development of an automated tool that continuously monitored the gas phase within the vadose zone. Measurements showed that the gas plume had a heterogeneous spatial and temporal variation. Mathematical calculations performed on the time series of the gas species showed that diffusive transport mainly occurred in the porous media. However, every stage of the migration could not be driven by diffusive process as shown by the exponential regression. A non-identified transport mechanism may have occurred during the increase of concentration. He was proven to be a suitable temporal tracer for a CO2 leakage as it was a good temporal precursor. Even if the process was weaker than in the former injection experiments, Kr could show help foreseeing the extent of the gas plume within the pilot site. CH4 was also shown to be an excellent temporal precursor of CO2 arrival. The amount of gas migrating through the preferential path identified in the previous experiment was weaker than in the previous study. Moreover, the monitoring showed that a significant amount of injected gas migrated deeper in the vadose zone. The ratios CO2/Kr vs. CO2/He and the evolution of CO2/Kr, CO2/He and CO2/CH4

put in evidence three groups of probes. The first consists in the subsurface probes and is characterized by a potential reactive transport of CO2 through the vadose zone such as gas dissolution in the aqueous phase. The second group gathers the closest probes to the injection point and underlines a very slow return to baseline value through diffusion. The third group is characterized by a competition between the process occurring in the first and second group. Isotopic measurement of Kr could not bring relevant information about the CO2 fates into the vadose zone. However, it shows the possible presence of mechanism transport such as vertical flux and gravitational settlings. Observations from both of all the leakage experiment and future laboratory experiment could improve our understandings of the buffering zone and help to foresee CO2 leakage for future storage site.

Riedel, M., Scherwath, M., Römer, M., Veloso, M., Heesemann, M., Spence, G.D., 2018. Distributed natural gas venting offshore along the Cascadia margin. Nature Communications 9, Article 3264.

https://doi.org/10.1038/s41467-018-05736-x

Widespread gas venting along the Cascadia margin is investigated from acoustic water column data and reveals a nonuniform regional distribution of over 1100 mapped acoustic flares. The highest number of flares occurs on the shelf, and the highest flare density is seen around the nutrition-rich outflow of the Juan de Fuca Strait. We determine ∼430 flow-rates at ∼340 individual flare locations along the margin with instantaneous in situ values ranging from ∼6 mL min−1 to ∼18 L min−1. Applying a tidal-modulation model, a depth-dependent methane density, and extrapolating these results across the margin using two normalization techniques yields a combined average in situ flow-rate of ∼88 × 106 kg y−1. The average methane flux-rate for the Cascadia margin is thus estimated to ∼0.9 g y−1m−2. Combined uncertainties result in a range of these values between 4.5 and 1800% of the estimated mean values.

Rimmer, P.B., Xu, J., Thompson, S.J., Gillen, E., Sutherland, J.D., Queloz, D., 2018. The origin of RNA precursors on exoplanets. Science Advances 4, Article eaar3302.

http://advances.sciencemag.org/content/4/8/eaar3302.abstract

Given that the macromolecular building blocks of life were likely produced photochemically in the presence of ultraviolet (UV) light, we identify some general constraints on which stars produce sufficient UV for this photochemistry. We estimate how much light is needed for the UV photochemistry by experimentally measuring the rate constant for the UV chemistry (“light chemistry”, needed for prebiotic synthesis) versus the rate constants for the bimolecular reactions that happen in the absence of the UV light (“dark chemistry”). We make these measurements for representative photochemical reactions involving SO4

-2 and HS−. By balancing the rates for the light and dark chemistry, we delineate the “abiogenesis zones” around stars of different stellar types based on whether their UV fluxes are sufficient for building up this macromolecular prebiotic inventory. We find that the SO4

-2 light chemistry is rapid enough to build up the prebiotic inventory for stars hotter than K5 (4400 K). We show how the abiogenesis zone overlaps with the liquid water habitable zone. Stars cooler than K5 may also drive the formation of these building blocks if they are very active. The HS− light chemistry is too slow to work even for early Earth.

Rincón-Tomás, B., Duda, J.-P., Somoza, L., González, J., Schneider, D., Medialdea, T., Madureira, P., Hoppert, M., Reitner, J., 2018. Cold-water corals and hydrocarbon-rich seepage in the Pompeia Province (Gulf of Cádiz) – living on the edge. Biogeosciences Discussions 2018, 1-33.

https://doi.org/10.5194/bg-2018-372

Azooxanthellate cold-water corals (CWCs) are globally widespread and have commonly been found in areas of active fluid seepage. The relationship between the CWCs and these fluids, however, is not well understood. This study aims at unravelling the relationship between CWC development and hydrocarbon-rich seepage in the Pompeia Province (Gulf of Cádiz, Atlantic Ocean). This region comprises mud volcanoes, coral ridges and fields of coral mounds, which are all affected by the tectonically driven seepage of hydrocarbon-rich fluids. Rate and type of seepage (i.e. focused, scattered, diffused, eruptive), however, is tightly controlled by a complex system of faults and diapirs. Early diagenetic carbonates from the currently active Al Gacel MV exhibit δ13C-signatures down to −28.77‰ VPDB, indicating biologically derived methane as the main carbon source. The same samples contained 13C-depleted lipid biomarkers diagnostic for archaea such as crocetane (δ13C down to −101.2‰ VPDB) and PMI (δ13C down to −102.9‰ VPDB), evidencing microbially mediated anaerobic oxidation of methane (AOM). This is further supported by next generation DNA sequencing data, demonstrating the presence of AOM related microorganisms (ANME archaea, sulfate-reducing bacteria) in the carbonate. Embedded corals in some of the carbonates and CWC fragments exhibit less negative δ13C values (−8.08 to −1.39‰ VPDB), pointing against the use of methane as carbon source. Likewise, the absence of DNA from methane- and sulfide-oxidizing microbes in a sampled coral does not support a chemosynthetic lifestyle of these organisms. In the light of these findings, it appears that the CWCs benefit rather indirectly from hydrocarbon-rich seepage by using methane-derived authigenic carbonates as substratum for colonization. At the same time, chemosynthetic organisms at active sites prevent coral dissolution and necrosis by feeding on the seeped fluids (i.e. methane, sulfate, hydrogen sulfide), allowing cold-water corals to colonize carbonates currently affected by hydrocarbon-rich seepage.


https://doi.org/10.1029/2017GB005747

Abstract: We have analyzed decade‐long methane flux data set from a boreal fen, Siikaneva, together with data on environmental parameters and carbon dioxide exchange. The methane flux showed seasonal cycle but no systematic diel cycle. The highest fluxes were observed in July–August with average value of 73 nmol m−2 s−1. Wintertime fluxes were small but positive, with January–March average of 6.7 nmol m−2 s−1. Daily average methane emission correlated best with peat temperatures at 20–35 cm depths. The second highest correlation was with gross primary production (GPP). The best correspondence between emission algorithm and measured fluxes was found for a variable‐slope generalized linear model (r2 = 0.89) with peat temperature at 35 cm depth and GPP as explanatory variables, slopes varying between years. The homogeneity of slope approach indicated that seasonal variation explained 79% of the sum of squares variation of daily average methane emission, the interannual variation in explanatory factors 7.0%, functional change 5.3%, and random variation 9.1%. Significant correlation between interannual variability of growing season methane emission and that of GPP indicates that on interannual time scales GPP controls methane emission variability, crucially for development of process‐based methane emission models. Annual methane emission ranged from 6.0 to 14 gC m−2 and was 2.7 ± 0.4% of annual GPP. Over 10‐year period methane emission was 18% of net ecosystem exchange as carbon. The weak relation of methane emission to water table position indicates that space‐to‐time analogy, used to extrapolate spatial chamber data in time, may not be applicable in seasonal time scales.

Plain Language Summary: Methane emission from a boreal wetland was measured over one decade. Methane emission shows strong seasonal cycle, with highest emission in late summer and lowest emission during winter. No diel cycle was observed. The methane emission is an important part of the carbon balance of the wetland as 18% of carbon taken up as carbon dioxide was emitted back into atmosphere as methane. The seasonal cycle of the emission was controlled first by peat temperature and second by ecosystem photosynthesis. The interannual variability of methane emission was more related to photosynthesis. A large part of the interannual variability remained unexplained by the measured environmental parameters.



The lithium isotopic composition of foraminifera is an established tracer of long-term changes in the global silicate weathering cycle, following the assumption that foraminifera faithfully record the lithium isotopic composition (δ7Li) of seawater. In this study, we demonstrate by utilising benthic foraminifera (Amphistegina lessonii) that were cultured under decoupled pH-[CO3

2–] conditions, that foraminifera δ7Li is strongly dependent on pH. This is reinforced with δ7Li data from globally distributed core-top samples of Cibicidoides mundulus and Cibicidoides wuellerstorfi, which show the same negative correlation with pH. The dependency of δ7Li on pH is perhaps a surprising result given that lithium speciation in seawater is independent of both pH and carbonate ion speciation. The dependence of lithium incorporation on growth rate was assessed by measuring the calcium isotopic composition; no growth rate dependent incorporation was observed. Instead, we propose that the strength of the 6Li and 7Li hydration spheres (and hence their respective desolvation energy) is pH-dependent, resulting in a significant isotopic fractionation during the incorporation of lithium into foraminifer calcite. The core-top derived δ7Li-pH calibration is used to demonstrate the applicability of this δ11B-independent pH proxy in reconstructing deglacial variations in pH in the South Pacific. The use of foraminifera δ7Li to compliment δ11B-based pH reconstructions has the potential to provide insight into time-dependent variations in porewater/seawater δ11B, temperature and salinity, which were previously unresolvable.



Lacustrine and marine crude oils from different off-shore Brazilian basins were analyzed using a 7.2 Tesla LTQ FTICR-MS instrument. The samples were analyzed via electrospray ionization in the negative ion mode focusing on the polar compounds, i.e., nitrogen-, sulfur-, and oxygen-containing (NSO) compounds. We also employed a combination of other geochemical methods, such as GC-FID and GC-MS analyses, to characterize and assess the depositional environments of the different oil families. The results indicate that lacustrine oils tend to be enriched in Nx compounds, while marine oils show preference for Ox compounds. The dominant heteroatomic classes in crude oils are N1, followed by O1, O2, and N1O1 with remarkable differences in their distributions between marine and lacustrine, strongly suggesting the control by the kerogen type of the heteroatomic compounds found in these crude oils. Considerable differences in the DBE distribution of the main classes analyzed

between the crude oils allowed an efficient geochemical characterization regarding their origin. The use of negative ESI FTICR-MS as a geochemistry tool can provide additional information beyond that obtained with currently employed geochemical methods, resulting in the full comprehension of crude oil composition.

Ronholm, J., Goordial, J., Sapers, H.M., Izawa, M.R.M., Applin, D.M., Pontefract, A., Omelon, C.R., Lamarche-Gagnon, G., Cloutis, E.A., Whyte, L.G., 2018. Characterization of microbial communities hosted in quartzofeldspathic and serpentinite lithologies in Jeffrey Mine, Canada. Astrobiology 18, 1008-1022.


The microbial ecology and activity of serpentine deposits and associated hydrated minerals are largely unknown. Previous research has largely focused on microbial communities in active serpentinizing systems, whereas relatively little research has demonstrated the ability of serpentine deposits to host microbial communities after the cessation of serpentinization. Given the potential role of serpentinization reactions fueling primitive microbial metabolisms on early Earth and the identification of serpentine deposits on Mars, knowledge of these geobiological relationships and potential for serpentine to host extant microbial communities and preserve biosignatures is increasingly important for planetary exploration seeking signs of life. The selection of habitable sites most likely to yield putative biosignatures is crucial to mission success. In this study, we aimed to characterize, on the basis of both metabolic activity and taxonomic composition, the microbial communities hosted in two naturally co-occurring and mineralogically distinct substrates within the serpentine-rich Jeffrey Mine pit–igneous quartzofeldspathic intrusives and serpentinite. Detection of heterotrophic activity in both lithologies at 24°C, and in serpentinite at −5°C, demonstrated that each substrate had the ability to host a viable microbial community, at Mars-relevant temperatures. Targeted amplicon sequencing subsequently showed the presence of bacterial, fungal, and photosynthetic microbial communities in both substrates. Here, we have demonstrated the presence of a viable lithic microbial community within two rock types in the Jeffrey Mine and provided evidence that lithologies associated with serpentine deposits and proximal hydrated minerals have the ability to support diverse prokaryotic and eukaryotic microbial colonization.

Rontani, J.-F., Amiraux, R., Lalande, C., Babin, M., Kim, H.-R., Belt, S.T., 2018. Use of palmitoleic acid and its oxidation products for monitoring the degradation of ice algae in Arctic waters and bottom sediments. Organic Geochemistry 124, 88-102.


Degradation of palmitoleic acid (C16:1ω7), the main fatty acid component of sea ice-associated (sympagic) diatoms, was monitored in Arctic sea ice at the beginning of ice melting and in the underlying sinking particles and superficial bottom sediments. In sea ice, degradation of sympagic algae involved biotic oxidation induced by 10S-DOX-like lipoxygenase of unknown salinity-stressed attached bacteria, while photo- and autoxidation were limited. In the water column, strong hydratase and Z/E isomerase activity were observed. Hydration of unsaturated fatty acids seems to be a detoxification strategy, which is essential for bacterial survival when associated with free fatty acid-rich environments such as ice algae. In contrast, Z/E isomerisation of palmitoleic acid was attributed to the release of Fe2+ ions during radical-induced damage of the active site of the bacterial 10S-DOX-like lipoxygenase and Z/E isomerases. Due to the poor physiological state of their attached bacteria resulting from salinity stress in brine channels or toxicity of free ice algae fatty acids, sympagic algae appeared to be only very weakly biotically degraded within the water column. In bottom sediments,

free radicals resulting from 10S-DOX-like lipoxygenase activity induced a strong autoxidation of the ice algal material. The presence in bottom sediments of a significant proportion of oxidation products resulting from 10S-DOX-like lipoxygenase activity attested to the strong contribution of sea ice-derived OM released during the early stages of ice melt prior to deposition in the sediments. However, on the basis of the highest fatty acid photooxidation state observed in these sediments, an additional contribution of highly photooxidized material (ice algal material released at the end of ice melting or open water phytoplankton) seems likely. The degradation of hydroperoxides, resulting from biotic and abiotic degradation of palmitoleic acid, appeared to involve: (i) homolytic cleavage of the peroxyl group affording the corresponding hydroxy- and oxoacids, (ii) reduction to the corresponding hydroxyacids by peroxygenases, (iii) heterolytic proton-catalysed cleavage and (iv) conversion to allylic 1,4-diols by diol synthases and hydroperoxide isomerases.

Rosell, M., Palau, J., Mortan, S.H., Caminal, G., Soler, A., Shouakar-Stash, O., Marco-Urrea, E., 2019. Dual carbon - chlorine isotope fractionation during dichloroelimination of 1,1,2-trichloroethane by an enrichment culture containing Dehalogenimonas sp. Science of The Total Environment 648, 422-429.


Chlorinated ethanes are frequent groundwater contaminants but compound specific isotope analysis (CSIA) has been scarcely applied to investigate their degradation pathways. In this study, dual carbon and chlorine isotope fractionation was used to investigate for the first time the anoxic biodegradation of 1,1,2-trichloroethane (1,1,2-TCA) using a Dehalogenimonas-containing culture. The isotopic fractionation values obtained for the biodegradation of 1,1,2-TCA were ɛC = −6.9 ± 0.4‰ and ɛCl = −2.7 ± 0.3‰. The detection of vinyl chloride (VC) as unique byproduct and a closed carbon isotopic mass balance corroborated that dichloroelimination was the degradation pathway used by this strain. Combining the values of δ13C and δ37Cl resulted in a dual element C-Cl isotope slope of Λ = 2.5 ± 0.2‰. Investigation of the apparent kinetic isotope effects (AKIEs) expected for cleavage of a C-Cl bond showed an important masking of the intrinsic isotope fractionation. Theoretical calculation of Λ suggested that dichloroelimination of 1,1,2-TCA was taking place via simultaneous cleavage of two C-Cl bonds (concerted reaction mechanism). The isotope data obtained in this study can be useful to monitor natural attenuation of 1,1,2-TCA via dichloroelimination and provide insights into the source and fate of VC in contaminated groundwaters.

Royle, S.H., Oberlin, E., Watson, J.S., Montgomery, W., Kounaves, S.P., Sephton, M.A., 2018. Perchlorate-driven combustion of organic matter during pyrolysis-gas chromatography-mass spectrometry: Implications for organic matter detection on Earth and Mars. Journal of Geophysical Research: Planets 123, 1901-1909.

https://doi.org/10.1029/2018JE005615

Abstract: The search for life on Mars targets the detection of organic matter from extant or extinct organisms. Current protocols use thermal extraction procedures to transfer organic matter to mass spectrometer detectors. Oxidizing minerals on Mars, such as perchlorate, interfere with organic detection by thermal extraction. Thermal decomposition of perchlorate releases oxygen, which promotes combustion of organic carbon. We have assessed the minimum mass ratio of organic carbon to perchlorate required to detect organic matter by thermal extraction and mass spectrometry. Locations on Mars with organic carbon to perchlorate ratios above 4.7–9.6 should be targeted. Because habitability is enhanced by the presence of liquid water and because perchlorate is a water‐soluble salt, locations on Mars with evidence of past or recent liquid water are high priority targets.

Plain Language Summary: Missions to Mars look for evidence of organic molecules using thermal extraction techniques. Certain minerals on the Martian surface, such as perchlorate salts, break down during heating, releasing oxygen and causing the combustion of any organic matter, which may have been present. In this event organic carbon is lost to analysis as CO and CO2. We used the ratio of CO: CO2 produced as a proxy for the completeness of combustion when various ratios of organic matter and perchlorate where thermally decomposed together. This allowed us to find a minimum organic carbon: perchlorate mass ratio (~5 times) for the survival of organic molecules. Carbon monoxide can only be produced if there is an excess of carbon to oxygen, which could enable the survival of unoxidized organic molecules for their subsequent detection. Applying these findings to Mars suggests that we would not expect to be able to detect organic molecules in average Martian soil. Consequently, future life detection missions to Mars must search for areas that exceed this ratio, either by having more organic matter or less perchlorate, and locations with evidence of recent water activity or in the subsurface are most likely to fulfill both of these criteria.

Ruiz-Matute, A.I., Rodríguez-Sánchez, S., Sanz, M.L., Soria, A.C., 2018. Chapter 12 - Chromatographic technique: Gas chromatography (GC), in: Sun, D.-W. (Ed.), Modern Techniques for Food Authentication (Second Edition). Academic Press, pp. 415-458.

http://www.sciencedirect.com/science/article/pii/B9780128142646000128

Its high resolution and sensitivity make of gas chromatography (GC) one of the most useful techniques for assessment of food authenticity. In this chapter, fundamentals and instrumentation of GC, together with several outstanding applications aimed to determine the authenticity of foodstuffs at more risk (e.g. fats and oils, dairy products, honey, coffee, spices, fruit juices, and wines) are covered. The coupling of GC to mass spectrometry (GC-MS) affords valuable structural information for reliable identification of authenticity markers and/or to get insight into the adulterants employed. Moreover, the potential of comprehensive two-dimensional gas chromatography (GC×GC) for resolving the complex mixtures involved in most common food frauds and for detection of subtle adulterations is also discussed.

Ryan, S.E., Reynard, L.M., Crowley, Q.G., Snoeck, C., Tuross, N., 2018. Early medieval reliance on the land and the local: An integrated multi-isotope study (87Sr/86Sr, δ18O, δ13C, δ15N) of diet and migration in Co. Meath, Ireland. Journal of Archaeological Science 98, 59-71.


Three early medieval Irish communities within a 30-km radius in Co. Meath, Ireland, have been examined using multiple isotopes (87Sr/86Sr, δ18O, δ13C, δ15N) to elucidate human and domesticated animal subsistence and provenance. Existing 87Sr/86Sr data from geochemical mapping of contemporary soils, plants and streamwater were compared to human and animal tooth enamel 87Sr/86Sr to assess potential past human migration, in combination with δ18O from bone collagen. Oxygen isotope (δ18O) values of human bone collagen are notably invariable, 10.0 ± 0.6‰ (n = 36), for the three archaeological sites: Collierstown, Johnstown and Raystown. Fauna (sheep, pigs, cats and a dog) δ18Ocollagen from Raystown are distinctly grouped between and among certain species, the first instance to our knowledge of such a result. The aggregate faunal data demonstrate that δ18Ocollagen values of faunal remains should not be used to infer local δ18O ranges for humans.

Nitrogen isotope (δ15N) values for both domesticated animal (9.8 ± 1.7‰) and adult human (12.0 ± 0.8‰) bone collagen are tightly constrained suggesting a similar source of protein in the diet of humans. A mean carbon isotope (δ13C) value of −21.0 ± 0.4‰ for adult humans indicates

overwhelming terrestrial sources of foodstuffs. Strontium isotope ratios (87Sr/86Sr) from human dental enamel range from 0.7085-0.7110 (n = 25). Two individuals (R841 and R854), both from Raystown, are statistical outliers based on their 87Sr/86Sr and δ13C values and are likely migrants to the locality where they were buried. We note that one of these putative migrants met a particularly violent end.

Satolli, S., Lanci, L., Muttoni, G., Di Cencio, A., 2018. The Lower Toarcian Serrone Marls (Northern Apennines, Italy): A 3.5 Myr record of marl deposition in the aftermath of the T-OAE. Palaeogeography, Palaeoclimatology, Palaeoecology 508, 35-47.


The early Toarcian sedimentary record is frequently characterized by the occurrence of marls, shales, and organic rich facies comprising the Toarcian oceanic anoxic event (T-OAE), which are broadly synchronous to the emplacement of the Karoo-Ferrar large igneous province (LIP) with a main pulse at ~181.7 Ma. Here we describe the chronology and rock magnetic properties of the early Toarcian Marne del Serrone Formation (Serrone Marls) from the Monte Serrone section in the Northern Apennines of Italy, and interpret them as reflecting the local environmental response to the transient CO2 rise and accelerated hydrological cycle most likely induced by the emplacement of the Karoo-Ferrar LIP. The studied 62 m-thick section is characterized by a succession of micritic limestones and marls, interrupted by a few slumps, and contains a record of the T-OAE represented by posidonia beds and a ~40 cm-thick black shale interval. The age of the section has been constrained using magnetostratigraphy and ammonite biostratigraphy to the Spinatum to Variabilis zones. Rock-magnetic properties have been used to characterize fluctuations in the magnetite and hematite input throughout the section. Spectral analysis of continuous IRM2.5T and IRM0.1T/IRM2.5T records indicates a duration of the studied marly interval of ca. 3.5 Myr, regarded as a first-order estimate of the duration of the response of the environmental system (hydrological cycle) to the transient climate perturbation triggered by the emplacement of the Karoo-Ferrar LIP, and a duration of the Bifrons zone of ca. 3.4 Myr.


https://doi.org/10.1007/s00203-018-1516-0

The level of catalase and superoxide dismutase induction, as well as generation of superoxide anion radical in cells and accumulation of hydrogen peroxide in the culture medium were researched in three strains of oil-degrading bacteria Achromobacter xylosoxidans at cultivation in rich nutrient medium and in the media with hydrocarbons as the only source of carbon. The effects of pentane, decane, hexadecane, cyclohexane, benzene, naphthalene and diesel fuel were evaluated. It was determined that in the microbial cell on media with hydrocarbons, the generation of superoxide anion radical increases, accumulation of hydrogen peroxide and induction of superoxide dismutase synthesis occur, and catalase activity is reduced. Oxidative stress in the cells of A. xylosoxidans was caused by biotransformation of all the studied hydrocarbons. The most pronounced effect was observed at incubation of bacteria with cyclohexane, pentane, diesel fuel, benzene and naphthalene.

Schaepe, K., Bhandari, D.R., Werner, J., Henss, A., Pirkl, A., Kleine-Boymann, M., Rohnke, M., Wenisch, S., Neumann, E., Janek, J., Spengler, B., 2018. Imaging of lipids in native human bone

sections using TOF–secondary ion mass spectrometry, atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization Orbitrap mass spectrometry, and Orbitrap–secondary ion mass spectrometry. Analytical Chemistry 90, 8856-8864.


A method is described for high-resolution label-free molecular imaging of human bone tissue. To preserve the lipid content and the heterogeneous structure of osseous tissue, 4 μm thick human bone sections were prepared via cryoembedding and tape-assisted cryosectioning, circumventing the application of organic solvents and a decalcification step. A protocol for comparative mass spectrometry imaging (MSI) on the same section was established for initial analysis with time-of-flight secondary ion mass spectrometry (TOF-SIMS) at a lateral resolution of 10 μm to <500 nm, followed by atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization (AP-SMALDI) Orbitrap MSI at a lateral resolution of 10 μm. This procedure ultimately enabled MSI of lipids, providing the lateral localization of major lipid classes such as glycero-, glycerophospho-, and sphingolipids. Additionally, the applicability of the recently emerged Orbitrap–TOF-SIMS hybrid system was exemplarily examined and compared to the before-mentioned MSI methods.



The Mediterranean Peninsula increasingly suffers from droughts and aridity, the first consequences of global climate change in that region. Precise scenarios for the region's future climate predictions require knowledge about the processes of past climate changes, but information about the Western Mediterranean climate and its history is controversial. For this study, we applied compound-specific δ13C and δ2H analyses on long-chain n-alkanes in the ~8 m El Paraíso loess-paleosoil sequence (LPS), Central Spain, to investigate climate and environmental changes during the Late Quaternary. The δ13C values are most enriched during marine isotope stage (MIS) 3, indicating more arid conditions, while lower values during MIS 4 and 2 are interpreted to document more humid conditions. Low values are also recorded for the Holocene colluvium, which can at least partly be explained with higher concentrations in atmospheric CO2. The δ2H values are mostly enriched during the last glacial compared to the Holocene. We suggest that this is mainly controlled by isotopic effects related to the moisture source, yet other possible effects like evapotranspirative enrichment and changes in atmospheric circulation patterns shouldn't be ruled out. Our results corroborate previous findings based on leaf wax patterns, geomorphological records, and climate models. They all indicate relatively humid conditions during MIS 2 compared to more arid phases during MIS 3.

Schmid, S., Smith, P.M., Woltering, M., 2018. A basin-wide record of the Late Cambrian Steptoean positive carbon isotope excursion (SPICE) in the Amadeus Basin, Australia. Palaeogeography, Palaeoclimatology, Palaeoecology 508, 116-128.


The Cambrian Paibian sedimentary succession of the central Australian Amadeus Basin contains a sequence of supratidal to subtidal shallow marine siliciclastic and oolitic, stromatolitic limestones and dolostones. Basin-wide sequence stratigraphy in combination with biostratigraphy revealed the G. stolidotus Zone within a 3rd-order transgressive systems tract (TST). The westward transgression

caused changes from a fluvial-dominated depositional environment towards a shallow-marine oolitic carbonate shoal environment. The eastern succession is dominated by stromatolitic, oolitic carbonate rocks with 2- to 5-m 5th-order shoaling upward cycles with several 4th-order cycles. The change from TST to HST (highstand systems tract) is marked by a maximum flooding surface within the Goyder Formation, which coincides with the peak of the Steptoean Positive Carbon Isotope Excursion (SPICE). The SPICE shows a facies-independent, synchronous positive δ13C excursion of 5‰ in a 130 m interval in 8 sections across a ~460 km transect. The SPICE peak is lowest in the nearshore successions (+0.4‰ δ13C), and highest in the platform succession (+4.9‰ δ13C) and is interpreted to be related to the chemical gradient of seawater and mixing of the DIC with atmospheric CO2-derived (i.e. terrestrial) bicarbonate. The recovery from SPICE is recorded by 4th-order shoaling upward cycles that compose the 3rd-order HST. This is the first time that sequence stratigraphy and biostratigraphy has been combined with carbon isotope chemostratigraphy across the nearshore to subtidal Cambrian basin succession in Australia.

Schmieder, M., Shaulis, B.J., Lapen, T.J., Kring, D.A., 2018. U–Th–Pb systematics in zircon and apatite from the Chicxulub impact crater, Yucatán, Mexico. Geological Magazine 155, 1330-1350.

https://doi.org/10.1017/S0016756817000255

This work presents a systematic study of zircon and apatite in melt-bearing impactites from the annular trough of the ~180 km and ~66.04 Ma Chicxulub impact crater, Yucatán, Mexico, using in situ laser ablation – inductively coupled plasma mass spectrometry, in which the petrologic context of the analysed minerals was assessed. Geochronologic U–Pb results for variably shocked zircon from the Yaxcopoil-1 core, including monocrystalline grains and neocrystallised granular aggregates, yielded a discordant array of ages representing the Early Palaeozoic age of the crystalline–metamorphic Maya block in the crater basement and the timing of the Chicxulub impact, respectively, and provide evidence for impact-induced resetting of the U–Pb system. Zircon and fluor-chlorapatite from the Yaxcopoil-1 core, and fluorapatite in clasts of impact melt from the Yucatán-6 core have low 206Pb/204Pb, suggesting the presence of detectable common Pb. The Chicxulub impactites were altered in an initially hot hydrothermal system that lasted up to ~2 Myr; locally, Pb-rich sulphides precipitated. Hydrothermal conditions did not reset the U–Th–Pb systematics of relict zircon, however, due to elevated closure temperatures for Pb diffusion at the fast cooling rates associated with the crater locations of the Yucatán-6 and Yaxcopoil-1 boreholes. Thus, the zircon preserves pre-impact and impact-related ages, rather than those of the hydrothermal system. In contrast, no useful geochronologic information was obtained from relict apatite, because common Pb in these grains overwhelmed radiometrically derived isotope ratios.

Schneider-Mor, A., Zilberman, T., Korngreen, D., 2018. Global and regional variations in tropical marine environments of Gondwana as revealed by a multi-stable isotope study, Middle Triassic (Anisian), Israel, Levant Basin. Palaeogeography, Palaeoclimatology, Palaeoecology 507, 115-128.


The world during the early Middle Triassic (Anisian) was characterized by a distinct recovery of the carbonate factory after the Permian–Triassic crisis. This recovery seems to have passed over the Anisian environment on the tropical northern margin of Gondwana (Israel, Levant Basin) and to have resulted in the low diversity of barren horizons of carbonate-secreting organisms. Four Anisian successions (the Ramon 1, Hameishar 1, Nafha 1, and David 1 boreholes) were studied to decode the factors preventing regional recovery. A multi-proxy analysis was performed on these boreholes, including the carbonate/siliciclastic ratio, total organic carbon (TOC), carbon/nitrogen (C/N) ratio and

inorganic carbon (δ13Ccarb), oxygen (δ18Ocarb), and nitrogen (δ15N) isotopic compositions. The aim of assessing the combination of these proxies was to characterize the geochemical conditions in the regional basins. These successions record two C-cycle perturbation events, characterized by negative shifts in δ13Ccarb values and recognized in most successions, indicating the land-marine teleconnection effect on the C-cycle perturbation. The δ18Ocarb excursions revealed similar oscillation trends, with global warming evidenced by increasing circumtropical precipitation and terrestrial influxes, whereas global cooling was reflected by increased carbonate factory production. The low δ15N values in all of the studied successions indicated the presence and flourishing of N-fixers. The absence or scarcity of carbonate-secreting organisms suggests that these N-fixers were the source of the carbonate fraction in the sediments. Episodic events with high δ15N values suggest an accumulation of terrestrial organic matter (OM) or oxygenation events, allowing short-term colonization by benthic fauna at the marine sites.

Schulze-Makuch, D., Crawford, I.A., 2018. Was there an early habitability window for Earth's Moon? Astrobiology 18, 985-988.


Our moon is uninhabitable and lifeless today. It has no significant atmosphere, no liquid water on its surface, no magnetosphere to protect its surface from solar wind and cosmic radiation, no polymeric chemistry, and it is subject to large diurnal temperature variations (e.g., Vaniman et al.,1991; Schulze-Makuch and Irwin, 2008). Thus, associating our Moon with habitability seems outrageous, and certainly it would have been just a decade ago. However, results from recent space missions, as well as sensitive analyses of lunar rock and soil samples, have indicated that the Moon is not as dry as previously thought (e.g., Anand, 2010; Hauri et al.,2017). In addition to the probable occurrence of water ice in permanently shadowed polar craters (e.g., Feldman et al.,1998; Baker et al.,2005; Lawrence, 2017), spectroscopic studies also indicate the presence of hydrated surface materials at high, but not permanently shadowed, latitudes (Clark, 2009; Pieters et al.,2009; Li and Milliken, 2017), with evidence for temporal variations over the course of a lunar day (Sunshine et al.,2009). In addition, recent studies of the products of lunar volcanism indicate that the lunar interior also contains more water than was once appreciated and that the lunar mantle may even be as comparably water-rich as Earth's upper mantle (see Hauri et al.,2017, for a review).

The existence of indigenous sources of water implies that the Moon may not always have been as dead and dry as it is today. Insofar as water is required for habitability (e.g., Kasting et al.,1993; although it is not the sole criterion, see Schulze-Makuch et al.,2011), we can speculatively identify two possible windows for lunar habitability. These may have occurred immediately following the accretion of the Moon and some hundreds of millions of years later following outgassing associated with lunar volcanic activity.

Current understanding is that the Moon originated from a gigantic impact 4.5 billion years ago (e.g., Stevenson and Halliday, 2014). The extent to which volatiles were preserved in the Moon-forming debris disk produced by this impact is model-dependent, but impediments to the diffusion of water molecules in a silicate-dominated vapor are expected to result in some water retention in the disk and therefore in the newly formed Moon (Nakajima and Stevenson, 2014; Hauri et al.,2017). The evidence for water concentrations of several hundred parts per million in the mantle source regions of lunar basalts (Hauri et al.,2017; Lin et al.,2017) indicates either that volatiles were indeed preserved during the formation of the Moon or that they were added shortly afterwards by impacting asteroids (e.g., Barnes et al.,2016).

Following accretion, the Moon is expected to have been largely molten, with its silicate components existing in the form of a lunar magma ocean (LMO). Such magma oceans are expected to outgas volatiles, leading to the formation of significant transient atmospheres (Elkins-Tanton, 2008). Indeed, Lin et al. (2017) have invoked degassing from the LMO to reconcile the relatively low abundance of water in the post-LMO lunar mantle (at most a few hundred parts per million) with their predictions of much higher values (possibly >1000 ppm) prior to LMO crystallization. On the other hand, some authors have argued that the LMO would have been initially dry following accretion, with the current mantle volatile budget having been added by a subsequent “late veneer” of asteroidal volatiles (e.g., Barnes et al.,2016; Hauri et al.,2017). However, in either case, it appears that significant quantities of water were present in the final stages of LMO evolution. Here, we merely note that outgassing 500 ppm water during the LMO phase (which would be required to bring the higher original values predicted by Lin et al. [2017] into agreement with current estimates) could in principle result in a surface water layer of an order of 1 km thickness. Of course, this would be a very optimistic estimate for the depth of any early lunar oceans—water would only be stable at the surface if protected by a sufficiently dense atmosphere, and significant losses would be expected owing to impact erosion (e.g., Melosh and Vickery, 1989)—but it illustrates how much water might potentially have been available.

Needham and Kring (2017) have suggested a second phase of outgassing, and associated peak in lunar atmospheric pressure, as a result of mare basalt eruptions ∼3.5 billion years ago. Gases derived from lava outpourings may have built up an atmosphere of about 10 mbar, which is above the triple-point pressure of water and about 1.5 times the present atmospheric pressure on Mars (and about 3 times as massive as the current martian atmosphere, given the difference in surface gravities). For comparison with the discussion above, Needham and Kring's estimated outgassing of water (∼1014 kg) would equate to a global layer having an average depth of ∼3 mm.

The duration of hypothetical lunar atmospheres was first studied by Vondrak (1974) and reviewed by Stern (1999). For the dense atmospheres considered here (with total masses >108 kg), the mass loss rate from a collisionally dominated atmosphere is expected to be ∼10 kg s−1, independent of atmospheric mass. The loss rate would be higher if impact erosion (Melosh and Vickery, 1989) or solar-wind stripping were important, but note that the early Moon may have been protected by a magnetic field (e.g., Hood, 2011), reducing the impact of the latter process. Based on these loss rates, Needham and Kring (2017) estimated a lifetime of ∼70 million years for the transient atmosphere generated by lunar volcanic activity, and the duration of a hypothetical denser and earlier atmosphere immediately following LMO crystallization could have been even longer. In principle, liquid water could have existed on the lunar surface during these times, and perhaps even more likely in protected subsurface environments such as interstitial pore spaces within the impact-generated mega-regolith.

It is instructive to put this time frame into perspective from a natural history point of view: Lazcano and Miller (1994) speculated that the time it took from the formation of suitable building blocks of life to the first cyanobacteria was no more than 10 million years. If they are correct, the transition from a nonliving to a living system might have taken place in considerably less of a time span, perhaps as little as a few thousand years. On the other hand, Orgel (1998) has argued that we simply do not understand how life, particularly its replication system, originated on primitive Earth; thus it is not possible to come up with a reliable time estimate. If abiogenesis is able to occur on short timescales, then an origin of life on the Moon cannot be excluded. Moreover, there is an alternative scenario for introducing life to the Moon: the early history of the Solar System was dominated by giant impacts and the transfer of meteorites between planets (e.g., Mileikowsky et al.,2000). During this time, and indeed subsequently, it is expected that meteorites blasted off the surface of Earth will have landed on the Moon (Armstrong et al.,2002; Gutiérrez, 2002; Schulze-Makuch, 2013), and some of them are expected to have survived the impact (e.g., Crawford et al.,2008). As life appears to have

been present on Earth by 3.8–3.5 billion years ago (e.g., Schopf, 1993; Schidlowski, 2001; Brasier et al.,2015; Nutman et al.,2016; Hassenkam et al.,2017; Schopf et al.,2018), and possibly by 4.1 or even 4.28 billion years ago (e.g., Bell et al.,2015; Dodd et al.,2017), it is possible that Earth life could have inoculated transiently habitable lunar environments. We note that the chances of survival of microorganisms within terrestrial meteorites impacting the Moon would be increased by the presence of even a tenuous lunar atmosphere because this would reduce the impact velocity.

Of course, habitability requires much more than just the presence of a significant atmosphere and liquid water. Other constraints that need to be satisfied have been elaborated elsewhere (e.g., Schulze-Makuch et al.,2011; Cockell et al.,2016). We do not know whether there were any intrinsic organic compounds on the Moon at that time, but even if not, these would likely have been delivered from Earth, carbonaceous asteroids, and perhaps other sources, via meteorite impacts (e.g., Pierazzo and Chyba, 1999; Crawford et al.,2008; Burchell et al.,2010; Matthewman et al.,2015; Svetsov and Shuvalov, 2015). Thus, sources of organics on the lunar surface may have been available. Moreover, as the early Moon appears to have had a magnetic field (e.g., Hood, 2011), its surface may have been partially protected from solar and cosmic radiation.

If these early habitable environments ever existed, would there be any evidence remaining? Clearly, we do not see the familiar water-modified topography on the Moon that we see on Mars (e.g., fluvial channels or crater rims that are altered by liquid water), and it is questionable whether any topographical evidence of early surface water would be preserved on the Moon after approximately 4 billion years of pounding by solar wind, cosmic radiation, and micrometeorites. On the other hand, there is some (albeit limited) evidence for oxidation and/or hydrothermal activity in lunar rocks (e.g., Shearer et al.,2014; Joy et al.,2015). One especially promising future line of inquiry, especially for evidence of near-surface water during the high point of mare volcanism, would be to search for evidence of hydration in paleoregolith layers trapped between lava flows dating from this time (see Crawford et al.,2010, for a discussion of lunar paleoregolith deposits). It is also interesting to note that Cannon et al. (2017) have proposed an early episode of hydration, resulting from magma ocean degassing, as the source of primordial clay mineral formation on Mars, and if such a process operated on early Mars, then it seems likely to have operated on the early Moon as well. Although it seems certain that if liquid water ever existed on the early Moon it would have been much less prevalent than on early Mars, evidence for it may yet turn up in studies of lunar samples.

Thus, if liquid water and a significant atmosphere were present on the early Moon for millions of years, it can be assumed that the lunar surface was at least transiently habitable and probably also had an inventory of the building blocks required for life. Whether life ever arose on the Moon, or was transported to it from elsewhere, is of course highly speculative and can only be addressed by an aggressive future program of lunar exploration (e.g., Crawford and Joy, 2014). An important aspect of such an exploration program would be obtaining samples from paleoregolith deposits dating from time of peak mare volcanism (i.e., at ∼3.5 Ga) to determine if hydrated conditions (or other evidence for habitable conditions, including possible biomarkers) existed at that time.

In addition, experiments could be conducted in lunar environment simulation chambers in laboratories on Earth to observe whether microorganisms can maintain viability under the environmental conditions predicted to have existed on the early Moon. Indeed, the surface conditions predicted by Needham and Kring (2017) are not very different from those routinely produced in Mars simulation chambers (Galletta et al.,2006; Jensen et al.,2008; de Vera et al.2013). Such facilities are available at many research institutions around the world and could easily be modified to simulate early lunar environmental conditions. Moon-analog experiments are already done on the International Space Station (ISS) as part of the BIOMEX project (Baqué et al.,2017), and methods to analyze these samples for microbial viability are being developed (Liu et al.,2018). Thus, we recommend utilizing

both Moon simulation chambers on our planet and on the ISS to test whether there might have been an early habitability window on the Moon.

Schwechheimer, S.K., Becker, J., Wittmann, C., 2018. Towards better understanding of industrial cell factories: novel approaches for 13C metabolic flux analysis in complex nutrient environments. Current Opinion in Biotechnology 54, 128-137.


The quantification of intracellular fluxes via 13C metabolic flux analysis has become one of the major techniques to support systems-based metabolic engineering of industrial production hosts. Commonly, 13C studies are conducted using minimal media, however, a great variety of industrial processes rely on complex medium compounds. The use of parallel 13C tracer experiments as well as analytical multi-readout of labeling data together with model-based simulation offer a great starting point to tackle such complex systems. Prominent examples will highlight the recent progress made.

Sedaghat, M., Rouhibakhsh, K., 2018. On prediction of asphaltene precipitation in different operational conditions utilization of LSSVM algorithm. Petroleum Science and Technology 36, 1292-1297.

https://doi.org/10.1080/10916466.2018.1471491

Asphaltene which is known as one of the fractions of oil, can cause the important problems during production of crude oil in reservoir, tubing and surface facilities so these problems can influence the production cost and time. In order to predicting and solving asphaltene problems, a powerful Least squares support vector machine (LSSVM) algorithm were developed for asphaltene precipitation estimation as function of dilution ratio, temperature, precipitant carbon number, asphaltene content and API of oil. A total number of 428 measured data were utilized to train and test of LSSVM algorithm. The average absolute relative deviation (AARD), the coefficient of determination (R2) and root mean square error (RMSE) were determined as 7.7569, 0.98552 and 0.26312 respectively. Based on these statistical parameters and graphical analysis it can be concluded that the predicting algorithm has enough reliability and accuracy in prediction of asphaltene precipitation.



In response to the Deepwater Horizon oil spill, critical research has tracked the changes in petroleum hydrocarbons with environmental weathering. There are limitations, however, whereby single analytical techniques cannot always identify the wide breadth of petroleum and petroleum-derived compounds. We explore the analytical capabilities of ramped pyrolysis-gas chromatography–mass spectrometry (Py-GC–MS) to evaluate environmental samples of petroleum hydrocarbons from the Deepwater Horizon oil spill. We show that bulk flow Py-GC–MS can quantify the overall degree of petroleum hydrocarbon weathering. Furthermore, thermal slicing Py-GC–MS can quantify specific compounds in the “thermal desorption zone” (50–370 °C), as well as characterize pyrolyzed fragments from non-GC-amenable petroleum hydrocarbons (including oxygenated hydrocarbons) in the “cracking zone” (370–650 °C). Our data also suggest an increase in thermochemical stability, concentration of oxygenated products and complexity of high molecular weight and/or polar

components with advanced weathering. This analysis not only elucidates weathering trends in Deepwater Horizon oil over several years, but also illustrates the analytical capacity of this method for future petroleum hydrocarbon investigations, filling a void in research connecting Py-GC–MS and environmentally weathered oil samples.

Sharma, A., Jagarapu, A., Micale, C., Walia, D., Jackson, S., Dhurjati, P.S., 2018. Modeling framework for biogenic methane formation from coal. Energy & Fuels 32, 8453-8461.


In situ biodegradation of coal to methane offers an innovative and attractive alternative to the prevailing methods of harnessing the energy potential of coal. This alternative approach employs a community of microorganisms to biologically generate methane from unmined coal and has the promise of causing less pollution, reducing the environmental impact of mining, and being potentially less expensive.(9,10,15−18) The goal of our work is to develop a novel, comprehensive, and quantitative mathematical modeling framework to better understand the process of biogenic methane formation from coal. Intermediate chemical species and metabolic pathways are identified using existing literature information and are incorporated into a lumped kinetic model, referred to as the Coal to Methane (C2M) Kinetic Model. Several intermediate compounds have been lumped into polyaromatics (PACs), long chain fatty acids (LCFAs), and mid chain fatty acids (MCFAs), etc. The simulations of the model and sensitivity analysis along with a metabolic pathway connectivity map are useful for guiding experimental design and establishing important intermediate metabolites and bottlenecks. The dependence of methane production on temperature and concentration of enzymes has been studied through sensitivity analysis of kinetic parameters, showing CO2 reduction and acetate cleavage play a significant role. Additionally, interdependence of MCFA hydrolysis to acetate and conversion of acetate to methane has been identified, implying acetate regulation as a key factor of methane formation. The mathematical model compares favorably to a limited set of experimental data provided by ArcTech Inc. Model parameters can aid in understanding the impact of metabolic bottlenecks on the bioconversion process and can be useful for monitoring or controlling the biogenic methane process.



Significance: We describe a situation in which bacteria typical of the human oral microbiome are organized spatially by gliding cells, species of Capnocytophaga, that move backward and forward over the substratum. The mobile adhesins that pull the cells over the substratum also attach to cells of nonmotile bacterial species, which are carried up and down the motile cells as cargo. The synchronized transport of nonmotile cargo bacteria helps to shape a polymicrobial community.

Abstract: The human microbiome is an assemblage of diverse bacteria that interact with one another to form communities. Bacteria in a given community are arranged in a 3D matrix with many degrees of freedom. Snapshots of the community display well-defined structures, but the steps required for their assembly are not understood. Here, we show that this construction is carried out with the help of gliding bacteria. Gliding is defined as the motion of cells over a solid or semisolid surface without the necessity of growth or the aid of pili or flagella. Genomic analysis suggests that gliding bacteria are present in human microbial communities. We focus on Capnocytophaga gingivalis, which is present

in abundance in the human oral microbiome. Tracking of fluorescently labeled single cells and of gas bubbles carried by fluid flow shows that swarms of C. gingivalis are layered, with cells in the upper layers moving more rapidly than those in the lower layers. Thus, cells also glide on top of one another. Cells of nonmotile bacterial species attach to the surface of C. gingivalis and are propelled as cargo. The cargo cell moves along the length of a C. gingivalis cell, looping from one pole to the other. Multicolor fluorescent spectral imaging of cells of different live but nonmotile bacterial species reveals their long-range transport in a polymicrobial community. A swarm of C. gingivalis transports some nonmotile bacterial species more efficiently than others and helps to shape the spatial organization of a polymicrobial community.

Silva, C.S., Pimentel, M.F., Amigo, J.M., García-Ruiz, C., Ortega-Ojeda, F., 2018. Chemometric approaches for document dating: Handling paper variability. Analytica Chimica Acta 1031, 28-37.


A non-destructive methodology based on Fourier Transformed Infrared Spectroscopy (FTIR) is proposed in this research to estimate the age of documents of different ages. Due the variability in the samples caused by their different chemical compositions, chemometric approaches were proposed to build one unique regression model able to determine the age of the paper regardless of its composition. PLS models were built employing Generalized Least Squares Weighting (GLSW) and Orthogonal Least Squares (OLS) filters to reduce the variability of samples from the same year. Afterwards, sparse PLS, which is an extension of the PLS model including a variable selection step, was applied to compare its performance with the preprocessing filters. All techniques proposed were compared to the initial PLS models, showing the potential of the chemometric approaches applied to FTIR data to estimate the age of unknown documents.

Singh, A.K., Kumar, A., Hakimi, M.H., 2018. Organic geochemical and petrographical characteristics of the Nagaur lignites, Western Rajasthan, India and their relevance to liquid hydrocarbon generation. Arabian Journal of Geosciences 11, Article 406.

https://doi.org/10.1007/s12517-018-3744-7

The article presents the geochemical and petrographical characteristics of Paleocene lignite deposits of the Nagaur Basin to appraise the regional rank variation, organic matter maturity, and liquid hydrocarbon generative potential. The petrographical investigation indicated that the analyzed lignites contain abundant huminite group macerals with a significant amount of the liptinite group macerals while the concentration of inertinite group is less in comparison to huminite and liptinite group. The huminite reflectance (%R0) indicates that lignite samples of Nagaur Basin are thermally immature in nature and lignite to sub-bituminous B in rank. Immaturity of samples has a significant influence on the proximate results of the samples, especially on moisture and volatile matter concentration and low fixed carbon percentage. The analyzed lignites have TOC and S2 values that range from 30.4 to 43.0 and 58.0 to 130.7 mg HC/g rock, respectively, which shows that these lignites have excellent hydrocarbon generation potential and make them industrially important, considering the huge lignite reserve in the study area region. The Rock-Eval pyrolysis and ultimate analysis also reveal that these lignite samples mainly contained mixed type II–III kerogens with significant potential for both liquid hydrocarbon and gas generation. These kerogens are dependable on the maceral composition that was derived from the microscopic study. The presence of the high huminite with significant amount of liptinite (more than 15%) macerals also suggests that these lignites can act as a good source rock for hydrocarbon generation.

Singh, H., Cai, J., 2018. A mechanistic model for multi-scale sorption dynamics in shale. Fuel 234, 996-1014.


Evidence from experimental studies related to sorption on nanoporous materials, coals, and most recently on shales suggests that the sorption of gas in these targets is not instantaneous, i.e. the time it takes for the gas to adsorb to its maximum capacity is not negligible. A recent experimental study showed that the sorption in shale rocks is non-instantaneous, i.e. there is a delayed effect in adsorption due to different mechanisms of sorption in different materials of shale, for e.g. in inorganic and organic matter. The current suite of models used to predict sorption in shale (e.g. Langmuir, BET, etc.) assumes an instantaneous equilibrium, which is not justifiable for sorption in shales.

Sorption of hydrocarbons and carbon dioxide in shale stratum is a complex mechanism that is affected by micro-scale affinity between the adsorbent-adsorbate, pore-scale heterogeneity of the surface with respect to the pore distribution, and structural heterogeneity of the system. These multi-phenomena effects are multi-scale in nature, and their impact on sorption cannot be predicted using simple models that assume instantaneous equilibrium. A model for reliable prediction of sorption in shales must take into account above discussed effects. This study proposes a mechanistic model for multi-scale sorption dynamics (referred as “MSSD”) in shale that accounts for molecular and pore-scale effects, in addition to the continuum-scale effects, by corresponding parameters that are relevant on those scales. Proposed model is validated against three experimental datasets that depict sorption dynamics in shale. The MSSD model is then used to investigate the efficiency of carbon storage in shale by adsorption when it is injected as a binary mixture with methane.

The proposed model makes it convenient to study the effects of molecular-scale to continuum-scale parameters on sorption in shale that are otherwise possible only through expensive means of experiments or molecular dynamic simulations.

Singh, M.B., Rampal, N., Malani, A., 2018. Structural behavior of isolated asphaltene molecules at the oil–water interface. Energy & Fuels 32, 8259-8267.


Asphaltenes are the heaviest component of crude oil, causing the formation of a stable oil–water emulsion. Even though asphaltenes are known to behave as an emulsifying agent for emulsion formation, their arrangement at the oil–water interface is poorly understood. We investigated the effect of asphaltene structure (island type vs archipelago type) and heteroatom type (Oxygen-O, Nitrogen-N, and Sulfur-S) on their structural behavior in the oil–water system. Out of six asphaltenes studied here, only three asphaltenes remain at the oil–water interface while others are soluble in the oil phase. Molecular orientation of asphaltene at the interface, position, and angle of asphaltene with the interface has also been determined. We observed that the N-based island type asphaltene is parallel, while the O-based island type asphaltene and N-based archipelago type are perpendicular to the interface. These asphaltene molecules are anchored at the interface by the heteroatom. The S-based asphaltenes (both island and archipelago type) and O-based archipelago type asphaltenes are soluble in the oil phase due to their inability to form a hydrogen bond with water and steric crowding near the heteroatom. This study will help in understanding the role of asphaltenes in oil–water emulsion formation based on its structure and how to avoid it.



13,16-Dimethyl octacosanedioic acid (iso-diabolic acid) is a major membrane-spanning lipid of subdivisions (SDs) 1, 3 and 4 of the Acidobacteria, a highly diverse phylum within the Bacteria. It has been suggested that these lipids are potential building blocks for the orphan bacterial glycerol dialkyl glycerol tetraethers (GDGT) that occur widely in a variety of environmental settings. Here, we expand the knowledge on the occurrence of iso-diabolic acid in Acidobacteria by examining the lipid composition of six strains belonging to SDs 6, 8, 10, and 23 of the Acidobacteria, not previously analyzed for these lipids. In addition, we examined 12 new strains belonging to SDs 1, 3 and 4. Acid hydrolysis of total cell material released iso-diabolic acid in substantial quantities (25–39% of all fatty acids) from the strains of SDs 1 and 3 (except “Candidatus Solibacter usitatus”), and, for the first time, strains of SD 6 (6–25%), but not from SDs 8, 10, and 23. The monoglycerol ether derivative of iso-diabolic acid was only dominantly present in SD 4 strains (17–34%), indicating that the occurrence of ether-bound iso-diabolic acid is mainly restricted to SD 4 species. Methylated iso-diabolic acid derivatives were encountered in SDs 1, 3, 4, and 6, but only SD 4 species produced 5-methyl iso-diabolic acid derivatives, whereas the other SDs formed 6-methyl iso-diabolic acids. This suggests that the position of methylation of iso-diabolic acid may be controlled by the phylogenetic affiliation within the Acidobacteria and thus may not be a direct but an indirect response environmental to environmental conditions as inferred from the bacterial GDGT distributions in soil, peat and rivers.

Sinninghe Damsté, J.S., Rijpstra, W.I.C., Hopmans, E.C., den Uijl, M.J., Weijers, J.W.H., Schouten, S., 2018. The enigmatic structure of the crenarchaeol isomer. Organic Geochemistry 124, 22-28.


Isolation of crenarchaeol and its isomer from marine surface sediments, followed by ether cleavage and GC–MS characterization using supersonic molecular beam (SMB) ionization of the biphytanes formed, revealed that the crenarchaeol isomer comprises a tricyclic biphytane that is stereochemically different from the tricyclic biphytane of crenarchaeol. This isomeric tricyclic biphytane was also released from the crenarchaeol isomer in extant Thaumarchaeotal biomass. Reinterpretation of previously obtained 13C NMR data of the crenarchaeol isomer suggested that the cyclopentane moiety adjacent to the cyclohexyl moiety of the tricyclic biphytane of the crenarcheaol isomers possesses the unusual cis stereochemistry in comparison to the trans stereochemistry of all cyclopentane moieties in crenarchaeol. This stereochemical difference likely affects the packing of lipid membranes of Thaumarchaeota and therefore provides a biophysical explanation for the role of the crenarchaeol isomer in the TEX86 palaeothermometer based on fossilized Thaumarcheotal lipids.



In this study, the van der Waals and Platteeuw model was coupled with the Cubic Plus Association (CPA) equation of state (EoS) for equilibrium calculations in systems with gas hydrates. It has been

applied to simple and complex multicomponent systems involving methane, ethane, propane, isobutane, carbon dioxide, nitrogen and hydrogen sulfide. Methanol, ethanol, monoethylene glycol, calcium chloride, sodium chloride and potassium chloride were contemplated as thermodynamic hydrate inhibitors. The calculations were performed in the presence of single and mixed inhibitors. The mole fraction of components in all phases were determined using flash algorithm procedures to improve the calculations accuracy. To evaluate the ability of the methodology, the prediction of hydrate phase behavior in the presence and absence of inhibitors was compared with the experimental data. Additionally, the binary interaction coefficients were considered as a linear function of temperature. Furthermore, the Langmuir constants were optimized for each gas hydrate former. The results obtained with the proposed approach agreed well with the experimental data, predominantly for hydrate systems comprising mixture of different inhibitors as salts and alcohols.

Smirnov, M.B., Fadeeva, N.P., Borisov, R.S., Poludetkina, E.N., 2018. The characteristics of the organic matter of the Upper Devonian Domanik-type deposits in the northern and central regions of the Volga-Ural Basin according to saturated biomarkers composition. Geochemistry International 56, 812-827.

https://doi.org/10.1134/S0016702918080104

The composition of saturated biomarkers (alkanes, steranes, and triterpanes) in the Upper Devonian sediments (the Sargaev, Semiluk, and Mendym horizons, the Famennian stage) that belong to the Domanik formation, which is widespread on the territory of the Volga-Ural basin, was studied. The section elongated from N to S that covers the northern and central regions of the Volga-Ural basin was observed. A set of 21 parameters was used to characterize saturated hydrocarbons, including those rarely used in geochemical studies. For each parameter a set of mean values for the considered region as a whole and its individual parts was calculated and distribution-density plots were built. It was established that the most representative parameter for characterizing the Domanik-type deposits as a whole is a highly specific parameter, that is, the ratio of 29,30-bisnorhopane C28 to hopane C29. Most of the characteristics of the genetic composition demonstrate the difference between the organic matter (OM) of the vault part of the region and the Mukhanov- Erokhovsky trough. There are large differences in the parameters that characterize the maturity of OM. The characteristic values of the parameters for both the vault and the depression zone are given; two to three genetic groups of OM were determined for the majority of the parameters in both regions. A method for constructing the distribution-density graphs of the parameters is proposed that makes it possible to take their features fully into account. Original Russian Text © M.B. Smirnov, N.P. Fadeeva, R.S. Borisov, E.N. Poludetkina, 2018, published in Geokhimiya, 2018, No. 8, pp. 774–790.

Smith, G.P., Fraccia, T.P., Todisco, M., Zanchetta, G., Zhu, C., Hayden, E., Bellini, T., Clark, N.A., 2018. Backbone-free duplex-stacked monomer nucleic acids exhibiting Watson–Crick selectivity. Proceedings of the National Academy of Sciences 115, E7658-E7664.


Significance: The columnar liquid crystal phases reported here are physical associations of the smallest molecular species to self-assemble into the duplex base-paired stacked columnar double-helical structures of nucleic acids. These assemblies of monomers can provide starting states capable of partitioning appropriate molecules from solution with a high degree of selectivity, acting as pathways for the prebiotic appearance of molecular selection, self-assembly, and, ultimately, of the sequence-directed assembly of polymers.

Abstract:

We demonstrate that nucleic acid (NA) mononucleotide triphosphates (dNTPs and rNTPs), at sufficiently high concentration and low temperature in aqueous solution, can exhibit a phase transition in which chromonic columnar liquid crystal ordering spontaneously appears. Remarkably, this polymer-free state exhibits, in a self-assembly of NA monomers, the key structural elements of biological nucleic acids, including: long-ranged duplex stacking of base pairs, complementarity-dependent partitioning of molecules, and Watson–Crick selectivity, such that, among all solutions of adenosine, cytosine, guanine, and thymine NTPs and their binary mixtures, duplex columnar ordering is most stable in the A-T and C-G combinations.

Song, K., Li, S., Wen, Z., Lyu, L., Shang, Y., 2018. Characterization of chromophoric dissolved organic matter in lakes on the Tibet Plateau, China, using spectroscopic analysis. Biogeosciences Discussions 2018, 1-50.

https://doi.org/10.5194/bg-2018-259

Spatiotemporal variations in the characteristics of fluorescent dissolved organic matter (FDOM) components from 63 lakes across the Tibet Plateau, China, are examined using excitation-emission matrix spectra (EEM) and fluorescence regional integration (FRI) from 2014 to 2017. Freshwater (N=135) and brackish water (N=109) samples from 63 lakes were grouped according to salinity or electrical conductivity. In order to compare results between the lakes, cumulative volumes beneath the EEM values (φi, i=I, II, III, IV, V) were normalized to a DOC concentration of 1 mg/L. EEM-FRI identified tyrosine-like (φI), tryptophan-like (φII), fulvic-like (φIII), microbial protein-like (φIV), and humic-like (φV) fluorescence regions, as well as their proportions (Pi). Chromophoric dissolved organic matter (CDOM) absorption parameters, fluorescence indices, average fluorescence intensities of the five fluorescent components and total fluorescence intensities (φT) differed under spatial variation among brackish and freshwater lakes (ANOVA, p<0.05). Principal component analysis (PCA) was used to assess and group five normalized FDOM components for all of the water samples. These results show that microbial protein-like (φIV), fulvic-like (φIII) and humic-like (φV) have positive correlations (R2>0.79, t-test, p<0.01), indicating that these FDOM components may originate from similar sources. A correlation also exists between normalized φ i (i=I, II, III, IV, V) and DOC concentrations with a salinity >19‰ (averaged EC, 23764μscm−1) (t-test, p<0.01), of which R2 f regression analysis showed a decreasing tendency with EC. Similar correlations between a(254) and DOC concentrations (t-test, p<0.01) are also evident for sunshine hours>2900h. Redundancy analysis (RDA) indicates that a(254) and a(350) have a correlation with CDOM in brackish lakes. a(254), HIX and a(350) were also correlated with water quality. Strong evapoconcentration, intense ultraviolet irradiance and landscape features of the Tibet Plateau may be responsible for the FDOM characteristics identified in this study.

Song, R., Cui, M., 2018. Molecular simulation on competitive adsorption mechanism of CH4/CO2 on shale kerogen. Arabian Journal of Geosciences 11, Article 403.

https://doi.org/10.1007/s12517-018-3750-9

Due to the fact that most shale gas is stored in the adsorption state on organic compounds of the formation, better understanding of adsorption mechanism of CH4/CO2 in shale kerogen not only contributes to figure out the reserves of shale gas but also is beneficial to shale gas exploitation and carbon sequestration. Using the basic experimental data of shale core from Yanchang Formation, Ordos Basin, China, four types of kerogen structure are constructed and used as inputs to molecular

simulation. The isothermal adsorption capacity of single-component and bi-component of CH4 and CO2 on kerogen is simulated and analyzed. The results indicate that the isothermal adsorption capacity of CH4/CO2 increases with the rising of maturity but decreases with temperature. The effect of kerogen type on adsorption capacity is as follows: type III > type II > type I. And the adsorption capacity of CO2 is larger than that of CH4, indicating the good potential of enhancing shale gas production and carbon sequestration.


https://doi.org/10.1007/s00216-018-1173-9

Chromatographic retention time peak shifts between consecutive analyses is a well-known fact yet not fully understood. Algorithms have been developed to align peaks between runs, but with no specific studies considering the causes of peak shifts. Here, designed experiments reveal chromatographic shift patterns for a complex peptide mixture that are attributable to the temperature and pH of the mobile phase. These results demonstrate that peak shifts are highly structured and are to a high degree explained by underlying differences in physico-chemical parameters of the chromatographic system and also provide experimental support for the alignment algorithm called the generalized fuzzy Hough transform which exploits this fact. It can be expected that the development of alignment algorithms enters a new phase resulting in increasingly accurate alignment by considering the latent structure of the peak shifts.


https://doi.org/10.5194/bg-15-4777-2018

In this comment, we outline two major concerns regarding some of the key data presented in this paper. Both of these concerns are associated with the natural abundance radiocarbon-methane (14C-CH4) data. First, no systematic methodology is presented, nor previous peer-reviewed publication referenced, for how these samples were collected, prepared, and ultimately analyzed for 14C-CH4. Not only are these procedural details missing, but the critical evaluation of them using gaseous and aqueous blanks and standards was omitted although these details are essential for any reader to evaluate the quality of data and subsequent interpretations. Second, due to the lack of methodological details, the source of the sporadic anthropogenic contamination cannot be determined and thus it is premature for the authors to suggest it was in the natural environment prior to sample collection. As the natural 14C-CH4 data are necessary for the authors' stated scientific objectives of understanding the origin of methane in the East Siberian Arctic Shelf, our comment serves to highlight that the study's objectives have not been met.

Srinivasan, P., Dunlap, D.R., Agee, C.B., Wadhwa, M., Coleff, D., Ziegler, K., Zeigler, R., McCubbin, F.M., 2018. Silica-rich volcanism in the early solar system dated at 4.565 Ga. Nature Communications 9, Article 3036.

https://doi.org/10.1038/s41467-018-05501-0

The ranges in chemical composition of ancient achondrite meteorites are key to understanding the diversity and geochemical evolution of planetary building blocks. These achondrites record the first episodes of volcanism and crust formation, the majority of which are basaltic. Here we report data on

recently discovered volcanic meteorite Northwest Africa (NWA) 11119, which represents the first, and oldest, silica-rich (andesitic to dacitic) porphyritic extrusive crustal rock with an Al–Mg age of 4564.8 ± 0.3 Ma. This unique rock contains mm-sized vesicles/cavities and phenocrysts that are surrounded by quench melt. Additionally, it possesses the highest modal abundance (30 vol%) of free silica (i.e., tridymite) compared to all known meteorites. NWA 11119 substantially widens the range of volcanic rock compositions produced within the first 2.5–3.5 million years of Solar System history, and provides direct evidence that chemically evolved crustal rocks were forming on planetesimals prior to the assembly of the terrestrial planets.

Standnes, D.C., 2018. Implications of molecular thermal fluctuations on fluid flow in porous media and its relevance to absolute permeability. Energy & Fuels 32, 8024-8039.


This paper addresses the challenge related to the understanding of varying absolute permeability when forcing fluid (mostly water is considered) through a porous medium at varying system temperatures. It is assumed that the total energy dissipation splits into two contributions, a viscous part and a thermal part. These two energy dissipation channels will exactly balance the supplied external energy. The thermal part has not been considered previously regarding forced water flow through porous media, and it is substantiated theoretically by comparison with the well-known Ludwig–Soret effect. It is based on a hypothesis that the flowing water is dissipating molecular kinetic energy to heat (thermal dissipation) due to an asymmetric spatial velocity distribution up- and downstream the solid matrix. Based on previous theoretical calculations, an expression can be derived showing that thermal dissipation will increase proportional with the total inner surface area of the porous medium and the square root of absolute temperature. The calculation assumes that the solid matrix in the porous media can be considered as a large collection of large macroscopic “Brownian particles” being stagnant relative to the flowing water phase. The measured total energy dissipated in the porous medium, equal to the supplied pressure, can be used to estimate two fit parameters, a weight factor with respect to viscous/thermal dissipation and a thermal dissipation efficiency factor, using a generalized version of Darcy’s law also accounting for changes in temperature reading. Absolute permeability can then be calculated as a function of temperature using a reference permeability. This expression was applied for two sets of experimental data reported in the literature. The calculated results showed excellent fit to the measured absolute permeability values, corroborating the hypothesis proposed. The fractional magnitude of the total viscous and total thermal dissipation terms varied typically from 0.8 to 0.3 and from 0.2 to 0.7, respectively, in the temperature range 20–160 °C. Hence, total thermal dissipation constitutes a significant part of the energy required to force fluids through porous media, even at ambient temperature, which may have important consequences for processes where temperature is varying significantly in space and time. The reported data for absolute permeability vs temperature in the literature show large scatter, and many hypotheses have been proposed to explain the data. Hence, further systematic empirical work investigating this challenge is very much encouraged using, e.g., fluids with different molecular weights and polarity and porous media with different mineralogy in addition to performing molecular dynamics simulations. The current paper offers a theoretical explanation for the phenomenon observed related to reduction in absolute permeability for increasing system temperature which hopefully can contribute to improved test design and interpretation of experimental data.

Stanley, G.D., Shepherd, H.M.E., Robinson, A.J., 2018. Paleoecological response of corals to the end-Triassic mass extinction: An integrational analysis. Journal of Earth Science 29, 879-885.

https://doi.org/10.1007/s12583-018-0793-5

The end-Triassic (also Triassic-Jurassic) mass extinction severely affected life on planet Earth 200 million years ago. Paleoclimate change triggered by the volcanic eruptions of the Central Atlantic Magmatic Province (CAMP) caused a great loss of marine biodiversity, among which 96% coral genera were get lost. However, there is precious little detail on the paleoecology and growth forms lost between the latest Triassic extinction and the Early Jurassic recovery. Here a new pilot study was conducted by analyzing corallite integration levels among corals from the latest Triassic and Early Jurassic times. Integration levels in corals from the Late Triassic and Early Jurassic were determined through both the Paleobiology Database as well as from a comprehensive museum collection of fossil corals. Results suggest that in addition to a major loss of diversity following the end-Triassic mass extinction, there also was a significant loss of highly integrated corals as clearly evidenced by the coral data from the Early Jurassic. This confirms our hypothesis of paleoecological selectivity for corals following the end-Triassic mass extinction. This study highlights the importance of assigning simple to advanced paleoecological characters with integration levels, which opens a useful approach to understanding of mass extinction and the dynamics of the recovery.

Star, B., Barrett, J.H., Gondek, A.T., Boessenkool, S., 2018. Ancient DNA reveals the chronology of walrus ivory trade from Norse Greenland. Proceedings of the Royal Society B: Biological Sciences 285, Article 20180978.

http://rspb.royalsocietypublishing.org/content/285/1884/20180978.abstract

The importance of the Atlantic walrus ivory trade for the colonization, peak, and collapse of the medieval Norse colonies on Greenland has been extensively debated. Nevertheless, no studies have directly traced medieval European ivory back to distinct Arctic populations of walrus. Analysing the entire mitogenomes of 37 archaeological specimens from Europe, Svalbard, and Greenland, we here discover that Atlantic walrus comprises two monophyletic mitochondrial (MT) clades, which diverged between 23 400 and 251 120 years ago. Our improved genomic resolution allows us to reinterpret the geographical distribution of partial MT data from 306 modern and nineteenth-century specimens, finding that one of these clades was exclusively accessible to Greenlanders. With this discovery, we ascertain the biological origin of 23 archaeological specimens from Europe (most dated between 900 and 1400 CE). These results reveal a significant shift in trade from an early, predominantly eastern source towards a near exclusive representation of Greenland ivory. Our study provides empirical evidence for how this remote Arctic resource was progressively integrated into a medieval pan-European trade network, contributing to both the resilience and vulnerability of Norse Greenland society.

Stawiarski, B., Otto, S., Thiel, V., Gräwe, U., Loick-Wilde, N., Wittenborn, A.K., Schloemer, S., Wäge, J., Rehder, G., Labrenz, M., Wasmund, N., Schmale, O., 2018. Controls on zooplankton methane production in the central Baltic Sea. Biogeosciences Discussions 2018, 1-31.

https://doi.org/10.5194/bg-2018-345

Several methanogenic pathways in oxic surface waters were recently discovered, but their relevance in the natural environment is still unknown. Our study examines distinct methane enrichments that repeatedly occur below the thermocline during the summer months in the central Baltic Sea. In agreement with previous studies in this region, we discovered differences in the methane distributions between the Western and Eastern Gotland Basin, pointing to in situ methane production below the thermocline in the latter (conc. CH4 14.1±6.1nM, δ13C CH4 −62.9‰). Through the use of a high resolution hydrographic model of the Baltic Sea, we showed that methane below the thermocline can be transported by upwelling events towards the sea surface thus contributing to the methane flux at

the sea/air interface. To quantify zooplankton-associated methane production rates, we developed a sea-going methane stripping-oxidation line to determine methane release rates from copepods grazing on 14C-labelled phytoplankton. We found that: (1) methane production increased with the number of copepods, (2) higher methane production rates were measured in incubations with Temora longicornis (125±49 fmol methane copepod−1d−1) than incubations with Acartia spp. (84±19 fmol CH4

copepod−1d−1) dominated zooplankton communities, and (3) methane was only produced on a Rhodomonas sp. diet, but not on a cyanobacteria diet. Furthermore, copepod-specific methane production rates increased with incubation time. The latter finding suggests that methanogenic substrates for water-dwelling microbes are released by cell disruption during feeding, defecation, or diffusion from fecal pellets. In the field, particularly high methane concentrations coincided with stations showing a high abundance of DMSP-rich Dinophyceae. Lipid biomarkers extracted from phytoplankton- and copepod-rich samples revealed that Dinophyceae are a major food source of the T. longicornis dominated zooplankton community, supporting the proposed link between copepod grazing, DMSP release, and the buildup of subthermocline methane enrichments in the central Baltic Sea.

Stephant, A., Garvie, L.A.J., Mane, P., Hervig, R., Wadhwa, M., 2018. Terrestrial exposure of a fresh Martian meteorite causes rapid changes in hydrogen isotopes and water concentrations. Scientific Reports 8, Article 12385.

https://doi.org/10.1038/s41598-018-30807-w

Determining the hydrogen isotopic compositions and H2O contents of meteorites and their components is important for addressing key cosmochemical questions about the abundance and source(s) of water in planetary bodies. However, deconvolving the effects of terrestrial contamination from the indigenous hydrogen isotopic compositions of these extraterrestrial materials is not trivial, because chondrites and some achondrites show only small deviations from terrestrial values such that even minor contamination can mask the indigenous values. Here we assess the effects of terrestrial weathering and contamination on the hydrogen isotope ratios and H2O contents of meteoritic minerals through monitored terrestrial weathering of Tissint, a recent Martian fall. Our findings reveal the rapidity with which this weathering affects nominally anhydrous phases in extraterrestrial materials, which illustrates the necessity of sampling the interiors of even relatively fresh meteorite falls and underlines the importance of sample return missions.



Although the extremely thermophilic archaea (Topt ≥ 70°C) may be the most primitive extant forms of life, they have been studied to a limited extent relative to mesophilic microorganisms. Many of these organisms have unique biochemical and physiological characteristics with important biotechnological implications. These include methanogens that generate methane, fermentative anaerobes that produce hydrogen gas with high efficiency, and acidophiles that can mobilize base, precious and strategic metals from mineral ores. Extremely thermophilic archaea have also been a valuable source of thermoactive, thermostable biocatalysts, but their use as cellular systems has been limited because of the general lack of facile genetics tools. This situation has changed recently, however, thereby providing an important avenue for understanding their metabolic and physiological details and also opening up opportunities for metabolic engineering efforts. Along these lines,

extremely thermophilic archaea have recently been engineered to produce a variety of alcohols and industrial chemicals, in some cases incorporating CO2 into the final product. There are barriers and challenges to these organisms reaching their full potential as industrial microorganisms but, if these can be overcome, a new dimension for biotechnology will be forthcoming that strategically exploits biology at high temperatures.

Sugitani, K., Kohama, T., Mimura, K., Takeuchi, M., Senda, R., Morimoto, H., 2018. Speciation of Paleoarchean life demonstrated by analysis of the morphological variation of lenticular microfossils from the Pilbara Craton, Australia. Astrobiology 18, 1057-1070.


The ca 3.4 Ga Strelley Pool Formation (SPF) of the Pilbara Craton, Australia, represents a Paleoarchean sedimentary succession preserving well-described and morphologically diverse biosignatures such as stromatolites and cellularly preserved microfossils. The SPF microfossil assemblage identified from three greenstone belts includes relatively large (20–80 μm in width), acid-resistant, organic-walled lenticular microfossils, which can be extracted using a palynological technique. In this study, we present results of measurements of over 800 palynomorphic specimens of SPF lenticular microfossils from 2 remote (∼80 km apart) localities that represent different depositional environments and thus different habitats, as evidenced by their distinct lithostratigraphic association and trace element geochemistry. We demonstrate statistically that the two populations are distinct in oblateness from a polar view and furthermore that each population comprises subpopulations defined by different areas and oblateness. This study may provide the earliest morphological evidence for speciation of unicellular organisms, which could have been allopatric (geographic) and adaptive. It can also be suggested that SPF lenticular microbes had highly organized cytoskeleton indispensable for strict control of the cell morphology of large and robust microbes, which in turn were likely advantageous to their prosperity and diversification.

Sun, G., Hu, J., Wang, Z., Li, X., Wang, W., 2018. Dynamic investigation of microbial activity in microbial enhanced oil recovery (MEOR). Petroleum Science and Technology 36, 1265-1271.

https://doi.org/10.1080/10916466.2018.1468776

The activity of reservoir microorganism is essential to Microbial enhanced oil recovery (MEOR). This present paper investigates the relationship between the microbial activity and production performance by means of long-scale & long-term experiments. The six rounds of nutritional injection was carried out in 135 days. During the microbial flooding experiment was performed recovering additional oil (10.44% Original Oil in Place, OOIP) after first water flooding. There is a positive correlation between water content and shannon index. And the fourth round of nutritional injection causes a considerable reduction in water content, while the concentration of Methyl-coenzyme reductase subunit alpha (mcrA) reaches peak value. In microbial flooding and reference water flooding, the concentration of mcrA maintained higher level with the low concentration of acetic acid. There are intimate correlation between water content and mcrA concentration & bacterial diversity (shannon index), which can be consider the symbol to guide the MEOR filed test.

Sun, T., Levin, B.D.A., Schmidt, M.P., Guzman, J.J.L., Enders, A., Martínez, C.E., Muller, D.A., Angenent, L.T., Lehmann, J., 2018. Simultaneous quantification of electron transfer by carbon matrices and functional groups in pyrogenic carbon. Environmental Science & Technology 52, 8538-8547.


Pyrogenic carbon contains redox-active functional groups and polyaromatic carbon matrices that are both capable of transferring electrons. Several techniques have been explored to characterize the individual electron transfer process of either functional groups or carbon matrices individually. However, simultaneous analysis of both processes remains challenging. Using an approach that employs a four-electrode configuration and dual-interface electron transfer detection, we distinguished the electron transfer by functional groups from the electron transfer by carbon matrices and simultaneously quantified their relative contribution to the total electron transfer to and from pyrogenic carbon. Results show that at low to intermediate pyrolysis temperatures (400–500 °C), redox cycling of functional groups is the major mechanism with a contribution of 100–78% to the total electron transfer; whereas at high temperatures (650–800 °C), direct electron transfer of carbon matrices dominates electron transfer with a contribution of 87–100%. Spectroscopic and diffraction analyses of pyrogenic carbon support the electrochemical measurements by showing a molecular-level structural transition from an enrichment in functional groups to an enrichment in nanosized graphene domains with increasing pyrolysis temperatures. The method described in this study provides a new analytical approach to separately quantify the relative importance of different electron transfer pathways in natural pyrogenic carbon and has potential applications for engineered carbon materials such as graphene oxides.

Sun, X., Jian, C., He, Y., Zeng, H., Tang, T., 2018. Probing the effect of salt on asphaltene aggregation in aqueous solutions using molecular dynamics simulations. Energy & Fuels 32, 8090-8097.


The presence of salts in different processes of oil production has attracted wide attention because of its effects on asphaltene aggregation, stability, interactions of emulsions, etc. In this work, molecular dynamics simulations were employed to study the effect of salts on aggregation of model asphaltenes. Four types of polyaromatic compounds possessing key structural features of continental-type asphaltenes were dispersed into NaCl solutions of different concentrations. These models have the same polyaromatic core but different lengths for the side chains. In the two models with relatively long side chains, the hydrophobic association among side chains is the main driving force for aggregation. The effect of salt on aggregation is therefore closely tied to its influence on the hydrophobic interaction: the salt ions promote the hydrophobic interaction at a low salt concentration while suppressing it at a high salt concentration. For the model with an intermediate side chain length, the hydrophobic interaction between side chains becomes less dominant and the salt has mutual influences on the core–core, chain–chain, and core–chain interactions. For the model with the shortest side chains, although the core–core and core–chain interactions are more important, the side chains still play a role in aggregation when the salt is present. Our results provide new insights into the fundamental understanding of the influence of salts on the aggregation and interaction behaviors of polyaromatic compounds in an aqueous environment.

Surjono, S.S., Hidayat, R., Wagimin, N., 2018. Triassic petroleum system as an alternative exploration concept in offshore western Timor Indonesia. Journal of Petroleum Exploration and Production Technology 8, 703-711.

https://doi.org/10.1007/s13202-017-0421-4

Located in the north-western part of Bonaparte Basin, offshore western Timor presents the opportunity for a distinct exploration concept due to the discovery of the Abadi gas field. A classic

Jurassic petroleum play did not develop as a proven reservoir and source rock in the study area due to severe erosion during the Valanginian event. Therefore, the Triassic interval requires assessment to reveal an alternative petroleum system in the study area. A petroleum system analysis utilising 2D seismic lines and three exploration wells was performed to construct a new exploration concept. The study showed that the Scythian Mount Goodwin interval could be considered a primary gas-prone source rock, with type II/III kerogen, a total organic content up to 2.09% and a hydrogen index that could reach 569 mg/g. Based on a study of a pseudo-well conducted here, the Mount Goodwin interval is found to have reached gas generation in the Early Cretaceous and expulsion in the Early Eocene. The potential reservoir rocks are the Carnian–Ladinian Challis and Anisian Pollard intervals. The Challis interval, the primary reservoir, has typical shoreline sandstones and is interbedded with claystones and limestone intercalations. Petrophysical and petrographic studies in this interval indicate good reservoir properties. However, the Pollard interval mainly consists of carbonates with minor claystones and has a low quality of reservoir properties. The intraformational shale of the Challis is considered as the potential regional seal, especially within areas that are not truncated by the Valanginian event. From the perspective of exploration, the Jurassic north-east–south-west-tilted fault blocks are still favourable for new discoveries in the offshore western Timor area.

Surowiec, I., Johansson, E., Stenlund, H., Rantapää-Dahlqvist, S., Bergström, S., Normark, J., Trygg, J., 2018. Quantification of run order effect on chromatography - mass spectrometry profiling data. Journal of Chromatography A 1568, 229-234.


Chromatographic systems coupled with mass spectrometry detection are widely used in biological studies investigating how levels of biomolecules respond to different internal and external stimuli. Such changes are normally expected to be of low magnitude and therefore all experimental factors that can influence the analysis need to be understood and minimized. Run order effect is commonly observed and constitutes a major challenge in chromatography-mass spectrometry based profiling studies that needs to be addressed before the biological evaluation of measured data is made. So far there is no established consensus, metric or method that quickly estimates the size of this effect. In this paper we demonstrate how orthogonal projections to latent structures (OPLS®) can be used for objective quantification of the run order effect in profiling studies. The quantification metric is expressed as the amount of variation in the experimental data that is correlated to the run order. One of the primary advantages with this approach is that it provides a fast way of quantifying run-order effect for all detected features, not only internal standards. Results obtained from quantification of run order effect as provided by the OPLS can be used in the evaluation of data normalization, support the optimization of analytical protocols and identification of compounds highly influenced by instrumental drift. The application of OPLS for quantification of run order is demonstrated on experimental data from plasma profiling performed on three analytical platforms: GCMS metabolomics, LCMS metabolomics and LCMS lipidomics.

Szafranek-Nakonieczna, A., Zheng, Y., Słowakiewicz, M., Pytlak, A., Polakowski, C., Kubaczyński, A., Bieganowski, A., Banach, A., Wolińska, A., Stępniewska, Z., 2018. Methanogenic potential of lignites in Poland. International Journal of Coal Geology 196, 201-210.


Microbial coal gasification is of great interest due to the necessity to develop more environmentally friendly methods of energy production. The two main lignite deposits in Poland (Bełchatów and Turów) have been studied for their natural methanogenic potential. The biological origin of gases

occurring in the investigated strata was confirmed by carbon stable isotope fractionation. Methanogenesis was examined via long-term anaerobic microcosm incubations which were performed using coal extracted from upper- and lowermost parts of the deposits at 10 to 40 °C. Present-day methane formation was distinguished from physical desorption by application of 2-bromoethane sulphonate (BES), an inhibitor of terminal methane formation steps. Furthermore, glycerol dialkyl glycerol tetraethers (GDGTs), were used to reconstruct the palaeoenvironmental conditions and explain how the lignite environment affects the methanogenic consortia.

The data obtained reveal that microbial degradation of lignite occurs in the uppermost layers of the coal seam at the Bełchatów lignite mine. Methane release was up to 0.064 ng CH4 g−1 day−1 at 30 °C. Biomarker analysis shows high abundance of GDGT-0 confirming the presence of methanogenic Archaea and implies that pH was an important factor regulating the development and activity of organic matter-degrading microbiota under neutral conditions as the most favourable for the methanogens.

Inactivation of methanogenic pathways by BES led to stimulation of bacterial respiration, which suggests the presence of an active bacterial community, putatively involved in the decomposition of lignin . The biomarker analysis, depicting metabolic capabilities of the microbiota (especially GDGT-0 and GDGT-0/crenarchaeol ratio) and recognition of palaeoenvironmental conditions, is a useful tool to determine the methanogenic potential of coals.

Tafuri, M.A., Goude, G., Manzi, G., 2018. Isotopic evidence of diet variation at the transition between classical and post-classical times in Central Italy. Journal of Archaeological Science: Reports 21, 496-503.


This work examines the carbon and nitrogen composition of human and animal collagen from the Roman necropolis of Lucus Feroniae (Rome, 1st–3rd century AD) and the Longobard cemetery of La Selvicciola in northern Latium (Viterbo, 7th century AD), with a special focus on possible dietary variations at the transition between classical and post-classical times. A substantial isotopic difference between the two series reveals distinct dietary practices at the two sites, especially the consumption of cereals and contribution of other foodstuffs to a mainly grain-based diet. We argue that such differences are explained through the social and cultural background of the two populations examined, where the isotopic variance of the Roman data is in line with that of a group of heterogeneous origin and varied dietary practices, while the tight clustering of isotopic signatures for the Longobard people reflects the foodways of a homogeneous group. Intra-site variation shows no significant difference according to the sex of the deceased. Outlying individuals might be explained through cultural practices that call for further insight. Isotopic data have shown to successfully reflect social and cultural phenomena of human groups in a changing world, in a way that other archaeological proxies have sometimes failed to achieve.

Taheri-Shakib, J., Rajabi-Kochi, M., Kazemzadeh, E., Naderi, H., Salimidelshad, Y., Esfahani, M.R., 2018. A comprehensive study of asphaltene fractionation based on adsorption onto calcite, dolomite and sandstone. Journal of Petroleum Science and Engineering 171, 863-878.


In this study, based on a new procedure, asphaltene fractions of Sarvak oil samples were determined based on their adhesion to calcite, dolomite, and sandstone surfaces and their properties were

evaluated. In irreversibly adsorbed asphaltenes, the highest concentrations of elements were 4.23 wt.% nitrogen (N) on the calcite surface, 7.12 wt.% sulfur (S) on dolomite surface, and 6.18 wt.% S and oxygen (O) on the sandstone surface. The dispersion of asphaltene fraction constituents on the surface, is approximately the same across the calcite sample, but in the dolomite sample, the highest adsorption of S correlates to the presence of magnesium (Mg). However, in sandstone samples, the highest S adsorption is achieved by potassium (K). The most dispersion of O occurs at the surface of the sandstone samples; according to matching through EDS mapping, due to the presence of silicon (Si), O has considerable dispersion. Asphaltene fractions also make lighter carbon compounds. It is important to note that in all samples, C17 is the highest peak seen in irreversibly adsorbed asphaltenes. In addition, the zeta potential is negatively affected by increasing the adsorption properties of asphaltene fractions; this depends on the concentration of asphaltene elements adhering to the surface. The O–H polar peak in the irreversibly absorbed asphaltene/sandstone sample is higher due to the presence of O, compared to the other samples. In all three mineral samples, bulk asphaltene and adsorbed fractions have roughly the same values for alkyl groups. The concentration of carbonyl, carboxylic acid, or derivative groups in adsorbed fractions in calcite and sandstone samples show a higher intensity.

Takahashi, M., Izumi, Y., Iwahashi, F., Nakayama, Y., Iwakoshi, M., Nakao, M., Yamato, S., Fukusaki, E., Bamba, T., 2018. Highly accurate detection and identification methodology of xenobiotic metabolites using stable isotope labeling, data mining techniques, and time-dependent profiling based on LC/HRMS/MS. Analytical Chemistry 90, 9068-9076.


A generally applicable method to discover xenobiotic metabolites is important to safely and effectively develop xenobiotics. We propose an advanced method to detect and identify comprehensive xenobiotic metabolites using stable isotope labeling, liquid chromatography coupled with benchtop quadrupole Orbitrap high-resolution tandem mass spectrometry (LC/HRMS/MS), data mining techniques (alignment, peak picking, and paired-peaks filtering), in silico metabolism prediction, and time-dependent profiling. The LC/HRMS analysis was carried out using Arabidopsis T87 cultured cells treated with unlabeled or with 13C- or 2H-labeled 2,4-dichlorophenoxyacetic acid (2,4-D). Paired-peak filtering enabled the accurate detection of 83 candidates for 2,4-D metabolites without any false positive peaks derived from solvents or the biological matrix. We confirmed 10 previously reported 2,4-D metabolites and identified 16 novel 2,4-D metabolites. Our method provides accurate detection and identification of comprehensive xenobiotic metabolites and represents a potentially useful tool for elucidating xenobiotic metabolism.

Tandon, S., Heidari, Z., 2018. Effect of internal magnetic-field gradients on nuclear-magnetic-resonance measurements and nuclear-magnetic-resonance-based pore-network characterization. SPE Reservoir Evaluation & Engineering 21, 609-625.

https://doi.org/10.2118/181532-PA

Summary Nuclear-magnetic-resonance (NMR) measurements have been extensively used for determining porosity, pore-size distribution, and fluid saturation in porous media. However, internal gradients of the magnetic field generated by the presence of paramagnetic or diamagnetic centers such as shale or clay particles can significantly affect NMR response. Consequently, the resulting interpretation for pore-size distribution and porosity is also affected. In this paper, we quantify the effect of internal magnetic-field gradients and spatial distribution of matrix components such as clay minerals on NMR response using pore-scale NMR numerical simulations. We also quantify the

influence of the aforementioned parameters on the NMR-based evaluation of porous media. We used the finite-volume method to numerically solve the Bloch (1946) equations and simulated magnetization decay in porous media. We cross validated the reliability of numerical simulations using analytical solutions given for spherical pores in different diffusion regimes. The model was then used for simulation of NMR response in the pore-scale images of sandstone and carbonate rocks. We used Larmor frequency of 2 MHz, external magnetic-field gradient of 0.10 T/m, and half-echo spacing time of 0.5 ms for simulating NMR response in pore-scale images of sandstones and carbonates. We then developed synthetic cases using actual rock images covering a wide range of spatial distribution of clay minerals (i.e., paramagnetic centers) to quantify the sensitivity of NMR decay to internal magnetic-field gradients. We quantified the sensitivity of NMR response for distribution of clays as thin laminae in the rock and as thin layers on the surface of the grains. The results showed that at low concentration (0.3 to 0.7%) of dispersed clay, there is a negligible effect of internal magnetic-field gradients on magnetization decay. At higher concentration of dispersed clay (5.1 to 7.3%), we observed a significant effect of internal magnetic-field gradients on magnetization decay. The presence of shale minerals can cause 53% variation in the location of the transverse-relaxation-time constant (T2) and up to 67% relative error in the assessment of dominant pore sizes. Shale laminations containing clay were found to produce an effect of up to 31.8% on T2 relaxation-time constant, which could cause a relative error of 50.0% in estimates of dominant pore size in the rock. The outcomes of this paper demonstrated the effect of heterogeneous rock mineralogy on NMR response. The effect of internal magnetic-field gradients generated by shale and clay on NMR becomes relevant when shale and clay particles are close to the pore fluid and their magnetic field starts to affect the distribution of magnetic field in the pore space. The results reveal the importance of characterizing the distribution of shale and clay minerals before interpreting NMR response and can potentially improve conventional techniques of pore-network characterization (pore-size distribution and pore volume) in the presence of clay minerals where internal magnetic-field gradients are not negligible.



The use of omics technologies to profile an organism's systemic response to environmental changes can improve the effectiveness of biomonitoring. In cell physiology, the dynamic characteristics of membranes can be used to identify lipid profiles that detect environmental threats and assess the health problems associated with them. The efficacy of this approach was demonstrated by profiling glycerophosphocholines (GPCs, a major membrane lipid class) in the coral Seriatopora caliendrum after exposure to Irgarol 1051. A quantitative biomonitoring model for this photosystem II herbicide was developed by correlating variations in coral lipid profile with herbicide exposure levels and degree of photoinhibition. After 4 days of exposure, the predominant changes correlated with photoinhibition were an increase in lyso-GPCs and saturated GPCs and a decrease in phosphatidylcholines with unsaturated C18 chains or a polyunsaturated C22 chain. A time-course experiment showed that most of these lipid changes occurred opposite to the initial response and that the persistent changes can be attributed to photosynthetic shortages and the membrane accommodation of photoinhibition-induced oxidative conditions. These changes can help predict risk factors leading to coral bleaching. In this study, the application of a lipidomic methodology to characterize the adaptation of coral to ambient contamination serves as a basis for advancing environmental monitoring and assessment.

Tang, C., 2018. Did Earth drive itself to a snowball? Science Bulletin 63, 1032-1033.


The icehouse model, in terms of low CO2 effect, elegantly accounted for the global cooling events on Earth’s surface, which has occurred at least several times in the history of Earth evolution. However, it does not appear to explain the great cooling events such as the Late Ordovician glaciation with an unusually high CO2 level of 4,000 ppmv [1], more than ten times higher than the CO2 level of today. Previous published records shows a CO2 increase during some glaciations [2], conflicting with the mainstream theory. Although Pagani et al. [3] later suggested that the evidences available support a drop in CO2 as a critical condition for global cooling, whether CO2 played a dominant role alone to cause the greenhouse-icehouse transition or whether a threshold level of CO2 ultimately induced global cooling cannot be determined from their results.

Donnadieu et al. [4] believed that the extensive cooling event during the Sturtian episode may have been resulted in due to a high obliquity (750 Ma). However, it is impossible to produce large glaciations in the case of mid to high latitude paleogeographies such as the Varangian-Vendian episodes (620–580 Ma). In addition, if we accept the idea that high obliquity is a possible trigger for glacial events such as the Sturtian glaciation, we have to found a mechanism to recover from the high obliquity. Seeking primarily to explain the paleomagnetic data, Williams (1975) proposed that Earth’s axial tilt (the obliquity of the ecliptic) exceeded 54° until the end of the Proterozoic [5], [6]. This implies that Earth’s climatic zonation would accordingly have been reversed in the Proterozoic, meaning lower insolation at low latitudes than at the poles. However, the seasonal cycle would have been greatly amplified, resulting in hot biannual summers, which do not favor glaciation. The Williams’s hypothesis of high-obliquity is not consistent with the observed glacial deposits with carbonates including inorganic sea-floor aragonite precipitates [5].

Despite the early skepticisms about the extent of CO2 effect or the high-obliquity effect on global cooling, these hypothesis were subsequently used to account for almost all anomalous cooling events. However, the causal relationship between the decrease of CO2 and global cooling from the original predictions of the hypothesis have not been confirmed.

Donnadieu et al. [7] try to explain the mechanism of Proterozoic snowball Earth by connecting it with the increase in runoff as a consequence of Rodinia breakup 800–700 Ma ago. They assume that the precipitation increase and runoff over the continents causes large quality of carbon dioxide to consume. However, Brune et al. [8] show that supercontinen breakup could also produce massive, long-term CO2 emissions. A clear geological link between continental rifting or breakup and CO2 degassing has been found on Earth, and more and more evidence of CO2 flux measurements have been documented in many types of rift systems, such as the Basin and Range Rift, the Rio Grande Rift, the Eger Rift, the East African Rift System, and its western branch. All of these data indicate that the continental rifting system provides important pathway to connect the vast carbon reservoir in Earth’s mantle to Earth’s surface [8].

Hence, precise quantitative evaluation of the effect of atmospheric CO2 fall in terms of runoff on the global cooling or the effect of atmospheric CO2 rise in terms of rift emission on the global warming requires a sophisticated approach in considering their heat balance.

The history of Earth’s evolution exhibits geologically active and quiescent periods, including magmatism, metamorphism, mineralization and tectonism. In the meantime, alternative cooling and warming have also occurred many times in the geological history of Earth. However, there is no consensus about the fundamental relationship between the thermal cycles and the episodic processes. Scientists generally ascribe the cause of cooling and warming either to bias in the effect of CO2 cycles

or astronomical effect. In a recent paper in Nature Geoscience[9], Spencer et al.’s discovery of a prominent magmatic gap seems challenge this geological belief. After a comprehensive evaluation of the geologic record from 2.4 to 2.0 Ga, they found a tectono-magmatic lull around 2.3–2.2 Ga. During this long geological quiescent period, global-scale continental magmatism and orogenic activity decreased greatly. The data also shows a lack of sedimentation activity on passive margin and rate of plate motions were relatively subdued. In fact, a period between 2.4 and 2.0 Ga called tectonic shutdown has previously been defined to interpret this tectono-magmatic lull [9].

The global cooling between 0.8 and 0.6 Ga, the second snowball Earth, also coincide with a prominent magmatic gap (the prominence of the zircon age lull) [1].

Spencer et al. [9] also posit that the geological quiescence ended about 2.2 billion years ago by a flare-up of juvenile magmatism, released significant thermal energy that had accumulated during the geological quiescence of the snowball Earth. This flux of mantle-derived energy could have provided a mechanism for Earth warming and cooling as a consequence of heat accumulation and loss underneath the crust. These events must be linked to the thermal cycle of the Earth’s interior rather than the surface external causes. The correspondence of a prominent magmatic lull with the extensive 0.1 Ga duration of snowball Earth suggests that it is not convincing to correlate the snowball Earth climate with an enhanced consumption of atmosphere CO2 through changes in runoff due to the dispersal of the supercontinent. This mechanism clearly ignores the fact that widespread continental rifting will result in huge heat loss, both through rifting induced de-compressive melting and lava eruption.

Although no unifying model explains all of the observed thermal fluctuations of Earth [1], we now know that there are many ways for Earth to trigger global cooling events by losing its interior heat. Moore and Webb [10] proposed a heat-pipe Earth model to provide an explanation of early Earth cooling though volcanism [10]. Sporadic processes such as enhanced plume activity and mountain building have been invoked as drivers of specific warming or cooling intervals. Lourenço et al. [11] even find that heat loss due to intrusive magmatism can be particularly efficient compared to volcanic eruptions. Recently, Stern and Miller [12] recognized that the Neoproterozoic Snowball Earth climate crisis may reflect the transition of Earth’s tectonic style from stagnant lid (single lithosphere) to the modern episode of plate tectonics, and only extraterrestrial triggers cannot be reconciled with the hypothesis that the Neoproterozoic climate crisis was caused by a prolonged (200–250 Ma) transition to plate tectonics. This implies that it must be caused by some reasons from interior of the Earth, which exactly support my idea: Earth drive itself to a snowball.

The idea of Earth’s thermal cycles is akin to heat and pressure fluctuation within a heating pressure cooker, with lithosphere playing the role of lid and rifting or breakup playing the role of valve [13], [14] (Fig. 1). Continuous interior heating warms up the Earth until catastrophic global-scale magmatism abruptly releases substantial heat, terminating the warming cycle and initiating a new cooling cycle, causing ice ages [14]. Given that the period of magmatic null does exactly match the period of the snowball Earth, it is perhaps no surprise to infer that the surface climate change should then be the result rather than the cause of Earth’s interior thermal cycles, with CO2 effect, in terms of icehouse or greenhouse, acting as the catalyst for the irreversible transition from climate warming to cooling, or vice versa.

References[1] N.R. McKenzie, B.K. Horton, S.E. Loomis, et al. Continental arc volcanism as the principal

driver of icehouse-greenhouse variability. Science, 352 (6284) (2016), pp. 444-447[2] M. Pagani, J.C. Zachos, K.H. Freeman, et al. Marked decline in atmospheric carbon dioxide

concentrations during the Paleogene. Science, 309 (2005), p. 600

[3] M. Pagani, M. Huber, Z. Liu, et al. The role of carbon dioxide during the onset of Antarctic glaciation. Science, 334 (2011), p. 1261

[4] Y. Donnadieu, G. Ramstein, F. Fluteau, et al. Is high obliquity a plausible cause for Neoproterozoic glaciations? Geophys Res Lett, 29 (23) (2002), p. 2127

[5] P.F. Hoffman, A.J. Kaufman, G.P. Halverson. Comings and goings of global glaciations on a neoproterozoic tropical platform in Namibia. GSA Today, 8 (5) (1998), pp. 1-9

[6] G.E. Williams, History of the Earth's obliquity. Earth-Sci Rev, 34 (1993), pp. 1-45[7] Y. Donnadieu, Y. Godderis, G. Ramstein, et al. A ‘snowball Earth’ climate triggered by

continental break-up through changes in runoff. Nature, 428 (2004), pp. 303-306[8] Brune S, Williams SE, Müller RD. Potential links between continental rifting, CO2 degassing and

climate change through time Sascha. Nat Geosci. https://doi.org/10.1038/s41561-017-0003-6.[9] C.J. Spencer, B.M. Murphy, C.L. Kirkland, et al. A Palaeoproterozoic tectono-magmatic lull as a

potential trigger for the supercontinent cycle. nat Geosci, 11 (2018), pp. 97-101[10] W.B. Moore, A.A.G. Webb. Heat-pipe Earth. Nature, 501 (2013), pp. 502-505[11] D.L. Lourenço, A.B. Rozel, T. Gerya, et al. Efficient cooling of rocky planets by intrusive

magmatism. Nat Geosci, 11 (2018), pp. 322-327[12] R.J. Stern, N.R. Miller. Did the transition to plate tectonics cause Neoproterozoic Snowball

Earth? Terra Nova, 30 (2018), pp. 87-94[13] C.A. Tang, Rifts of the Earth. Front Sci, 9 (26) (2015), pp. 4-23[14] C.A. Tang, S.Z. Li, Earth evolution as a thermal system, Geol J, 51 (S1) (2016), pp. 652-668

Tang, Y., Lemaitre, N., Castrillejo, M., Roca-Martí, M., Masqué, P., Stewart, G., 2018. The export flux of particulate organic carbon derived from 210Po / 210Pb disequilibria along the North Atlantic GEOTRACES GA01 (GEOVIDE) transect. Biogeosciences Discussions 2018, 1-40.

https://doi.org/10.5194/bg-2018-309

The disequilibrium between 210Po activity and 210Pb activity in seawater samples was determined along the GEOTRACES GA01 transect in the North Atlantic during the GEOVIDE cruise (May–June 2014). A steady-state model was used to quantify vertical export of particulate 210Po. The deficits of 210Po in the Iberian Basin and at the Greenland Shelf were strongly affected by vertical advection. Using the export flux of 210Po and the particulate organic carbon (POC) to 210Po ratio on total (>1µm) particles, we determined the POC export fluxes along the transect. Both the magnitude and efficiency of the estimated POC export flux from the surface ocean varied spatially within our study region. Export fluxes of POC ranged from negligible to 10mmolCm−2d−1, with enhanced POC export in the Labrador Sea. The cruise track was characterized by overall low POC export relative to net primary production (export efficiency<1–15%); but relatively high export efficiencies were seen in the basins where diatoms dominated the phytoplankton community. The particularly low export efficiencies in the Iberian Basin, on the other hand, were explained by the dominance of smaller phytoplankton, in particular, coccolithophores. POC fluxes estimated from the 210Po/210Pb and 234Th/238U disequilibria agreed within a factor of 3 along the transect, with higher POC estimates generally derived from 234Th. The differences were attributed to integration timescales and the history of bloom events.

Tartèse, R., Chaussidon, M., Gurenko, A., Delarue, F., Robert, F., 2018. Insights into the origin of carbonaceous chondrite organics from their triple oxygen isotope composition. Proceedings of the National Academy of Sciences 115, 8535-8540.


Significance: Refractory organic matter found in volatile-rich asteroidal materials essentially comprise the elements C, H, O, N, and S, which are thought to be important building blocks for life. Characterizing the origin(s) of these organics thus constitutes a key step to constrain the origin of life on Earth and appraise the habitability potential of other worlds. However, how and where these organics formed are still highly debated. In this study, we have determined the oxygen isotope composition of refractory organics from two families of carbonaceous chondrites. These data suggest that these organics formed in the nascent Solar System, possibly through chemical reactions occurring in the disk surrounding the young Sun.

Abstract: Dust grains of organic matter were the main reservoir of C and N in the forming Solar System and are thus considered to be an essential ingredient for the emergence of life. However, the physical environment and the chemical mechanisms at the origin of these organic grains are still highly debated. In this study, we report high-precision triple oxygen isotope composition for insoluble organic matter isolated from three emblematic carbonaceous chondrites, Orgueil, Murchison, and Cold Bokkeveld. These results suggest that the O isotope composition of carbonaceous chondrite insoluble organic matter falls on a slope 1 correlation line in the triple oxygen isotope diagram. The lack of detectable mass-dependent O isotopic fractionation, indicated by the slope 1 line, suggests that the bulk of carbonaceous chondrite organics did not form on asteroidal parent bodies during low-temperature hydrothermal events. On the other hand, these O isotope data, together with the H and N isotope characteristics of insoluble organic matter, may indicate that parent bodies of different carbonaceous chondrite types largely accreted organics formed locally in the protosolar nebula, possibly by photochemical dissociation of C-rich precursors.

ter Heijne, A., de Rink, R., Liu, D., Klok, J.B.M., Buisman, C.J.N., 2018. Bacteria as an electron shuttle for sulfide oxidation. Environmental Science & Technology Letters 5, 495-499.

https://doi.org/10.1021/acs.estlett.8b00319

Biological desulfurization under haloalkaliphilic conditions is a widely applied process, in which haloalkalophilic sulfide-oxidizing bacteria (SOB) oxidize dissolved sulfide with oxygen as the final electron acceptor. We show that these SOB can shuttle electrons from sulfide to an electrode, producing electricity. Reactor solutions from two different biodesulfurization installations were used, containing different SOB communities; 0.2 mM sulfide was added to the reactor solutions with SOB in absence of oxygen, and sulfide was removed from the solution. Subsequently, the reactor solutions with SOB, and the centrifuged reactor solutions without SOB, were transferred to an electrochemical cell, where they were contacted with an anode. Charge recovery was studied at different anode potentials. At an anode potential of +0.1 V versus Ag/AgCl, average current densities of 0.48 and 0.24 A/m2 were measured for the two reactor solutions with SOB. Current was negligible for reactor solutions without SOB. We postulate that these differences in current are related to differences in microbial community composition. Potential mechanisms for charge storage in SOB are proposed. The ability of SOB to shuttle electrons from sulfide to an electrode offers new opportunities for developing a more sustainable desulfurization process.

Tian, J., Ma, X., Zhou, J., Jiang, X., Lyle, M., Shackford, J., Wilkens, R., 2018. Paleoceanography of the east equatorial Pacific over the past 16 Myr and Pacific–Atlantic comparison: High resolution benthic foraminiferal δ18O and δ13C records at IODP Site U1337. Earth and Planetary Science Letters 499, 185-196.

http://www.sciencedirect.com/science/article/pii/S0012821X1830431X

We present astronomically tuned high resolution (∼3–4 Kyr) 15.8-Myr long benthic foraminiferal δ18O and δ13C records from IODP Site U1337 in the east equatorial Pacific, which provide a reference standard for stratigraphic correlation of deep sea sediments. A long-term glaciation history over the past 15.8 Myr has been recorded in the δ18O. Two of the most significant glaciation events include the East Antarctic Ice Sheet expansion (EAIE) at 13.8 Ma and the final onset of the Northern Hemisphere Glaciation (NHG) in 3.3–2.5 Ma. A series of Miocene and Pliocene glaciation events exist between the EAIE and NHG, which are important glaciation attempts before the Earth finally entered the full “icehouse” world in the late Pleistocene. A long-term ocean carbon isotope decrease over the past 15.8 Myr has been recorded in the δ13C. Ocean circulation change was the major cause of the ocean carbon isotope decrease in 9.4–8.1 Ma and 4–0 Ma, whereas strengthened continental chemical weathering controlled the long-term ocean carbon isotope decrease in most of the time of the past 15.8 Myr. The divergence in benthic foraminiferal δ13C and εNd provides strong evidence of significant ocean circulation change between 12.1 and 9.2 Ma which was probably related to the formation of the Isthmus of Panama. The internal feedbacks such as continental weathering and sea surface temperature change have great potential for modulating the weak 100 and 400 Kyr signals in astronomical forcing into strong 100 and 400 Kyr signals in global ice volume and carbon cycle.

Tong, X., Hu, J., Xi, D., Zhu, M., Song, J., Peng, P.a., 2018. Depositional environment of the Late Santonian lacustrine source rocks in the Songliao Basin (NE China): Implications from organic geochemical analyses. Organic Geochemistry 124, 215-227.


The Songliao Basin (SLB) located in northeastern China is one of the largest Cretaceous continental sedimentary basins in the world. The SLB is filled with sediments deposited in the Upper Jurassic, the Lower Cretaceous and the Upper Cretaceous epochs. The Nenjiang Formation (K2n) is subdivided into five members, where Member 2 (K2n2) was deposited in the late Santonian in the lower part of the Nenjiang Formation. This member is characterized by a thick succession of organic-rich source rocks. However, the complexity of the depositional environment raises questions about the specific factors that drove this accumulation of organic material. Here, we present data on the total organic carbon (TOC) contents and their stable carbon isotope values (δ13Corg), as well as biomarker data from 50 outcrop samples collected from the Yuewangcheng (YWC) section, in the southeastern SLB. According to the variations of the bulk organic parameters (TOC and δ13Corg) and biomarker indices, the profile could be divided into three stages (stages I–III). The distribution of biomarkers (n-alkanes, steranes and hopanes) and δ13Corg values indicate that the organic matter (OM) in the Lower K2n2 is derived largely from algae and macrophytes, with a minor input from bacteria and land plants. The water column was stratified, as indicated by the presence of gammacerane. Variations in the pristane/phytane (Pr/Ph) and aryl isoprenoids relative to phenanthrene ratio (A-i/P) suggest that bottom waters were anoxic during Stage I (31.5–26.0 m) and Stage II (26.0–16.3 m), with the anoxic layer impinging on the euphotic zone and a relative oxic environment at Stage III (16.3–0 m). This brackish environment persisted in the water over the interval represented by the section, as reflected by methytrimethyltridecyl chromans (MTTCs) Index (MTTCI) and α-MTTC/γ-MTTC ratios. Marine transgressions, with subsequent seawater incursions, can be detected with the presence of 24-n-propyl-cholestanes and 24-isopropyl-cholestanes in the Lower K2n2 sediments, especially during Stage I. These seawater incursions are closely correlated with anoxic conditions and the deposition of organic-rich source rocks.

Toshchakov, S.V., Lebedinsky, A.V., Sokolova, T.G., Zavarzina, D.G., Korzhenkov, A.A., Teplyuk, A.V., Chistyakova, N.I., Rusakov, V.S., Bonch-Osmolovskaya, E.A., Kublanov, I.V., Gavrilov, S.N., 2018. Genomic insights into energy metabolism of Carboxydocella thermautotrophica coupling

hydrogenogenic CO oxidation with the reduction of Fe(III) minerals. Frontiers in Microbiology 9, 1759. doi: 10.3389/fmicb.2018.01759.


The genus Carboxydocella forms a deeply branching family in the class Clostridia and is currently represented by three physiologically diverse species of thermophilic prokaryotes. The type strain of the type species, Carboxydocella thermautotrophica 41T, is an obligate chemolithoautotroph growing exclusively by hydrogenogenic CO oxidation. Another strain, isolated from a hot spring at Uzon caldera, Kamchatka in the course of this work, is capable of coupling carboxydotrophy and dissimilatory reduction of Fe(III) from oxic and phyllosilicate minerals. The processes of carboxydotrophy and Fe(III) reduction appeared to be interdependent in this strain. The genomes of both isolates were sequenced, assembled into single chromosome sequences (for strain 41T a plasmid sequence was also assembled) and analyzed. Genome analysis revealed that each of the two strains possessed six genes encoding diverse [Ni,Fe]-CO-dehydrogenases (maximum reported in complete prokaryotic genomes), indicating crucial role of carbon monoxide in C. thermautotrophica metabolism. Both strains possessed a set of 30 multiheme c-type cytochromes, but only the newly isolated Fe-reducing strain 019 had one extra gene of a 17-heme cytochrome, which is proposed to represent a novel determinant of dissimilatory iron reduction in prokaryotes. Mössbauer studies revealed that strain 019 induced reductive transformation of the abundant ferric/ferrous-mica mineral glauconite to siderite during carboxydotrophic growth. Reconstruction of the C. thermautotrophica strains energy metabolism is the first comprehensive genome analysis of a representative of the deep phylogenetic branch Clostridia Incertae Sedis, family V. Our data provide insights into energy metabolism of C. thermautotrophica with an emphasis on its ecological implications.

Tsuno, K., Grewal, D.S., Dasgupta, R., 2018. Core-mantle fractionation of carbon in Earth and Mars: The effects of sulfur. Geochimica et Cosmochimica Acta 238, 477-495.


Constraining carbon (C) fractionation between silicate magma ocean (MO) and core-forming alloy liquid during early differentiation is essential to understand the origin and early distribution of C between reservoirs such as the crust-atmosphere, mantle, and core of Earth and other terrestrial planets. Yet experimental data at high pressure (P)-temperature (T) on the effect of other light elements such as sulfur (S) in alloy liquid on alloy-silicate partitioning of C and C solubility in Fe-alloy compositions relevant for core formation is lacking. Here we have performed multi-anvil experiments at 6–13 GPa and 1800–2000 °C to examine the effects of S and Ni on the solubility limit of C in Fe-rich alloy liquid as well as partitioning behavior of C between alloy liquid and silicate melt (DC

alloy/silicate). The results show that C solubility in the alloy liquid as well as DCalloy/silicate decreases with

increasing in S content in the alloy liquid. Empirical regression on C solubility in alloy liquid using our new experimental data and previous experiments demonstrates that C solubility significantly increases with increasing temperature, whereas unlike in S-poor or S-free alloy compositions, there is no discernible effect of Ni on C solubility in S-rich alloy liquid.

Our modelling results confirm previous findings that in order to satisfy the C budget of BSE, the bulk Earth C undergoing alloy-silicate fractionation needs to be as high as those of CI-type carbonaceous chondrite, i.e., not leaving any room for volatility-induced loss of carbon during accretion. For Mars, on the other hand, an average single-stage core formation at relatively oxidized conditions (1.0 log unit below IW buffer) with 10–16 wt% S in the core could yield a Martian mantle with a C budget similar to that of Earth’s BSE for a bulk C content of ∼0.25–0.9 wt%. For the scenario where C was delivered to the proto-Earth by a S-rich differentiated impactor at a later stage, our model calculations

predict that bulk C content in the impactor can be as low as ∼0.5 wt% for an impactor mass that lies between 9 and 20% of present day Earth’s mass. This value is much higher than 0.05–0.1 wt% bulk C in the impactor predicted by Li et al. (Li Y., Dasgupta R., Tsuno K., Monteleone B., and Shimizu N. (2016) Carbon and sulfur budget of the silicate Earth explained by accretion of differentiated planetary embryos. Nat. Geosci.9, 781–785) because C-solubility limit of 0.3 wt% in a S-rich alloy predicted by their models is significantly lower than the experimentally derived C-solubility of ∼1.6 wt% for the relevant S-content in the core of the impactor.

Tucker, L.H., Conde-González, A., Cobice, D., Hamm, G.R., Goodwin, R.J.A., Campbell, C.J., Clarke, D.J., Mackay, C.L., 2018. MALDI matrix application utilizing a modified 3D printer for accessible high resolution mass spectrometry imaging. Analytical Chemistry 90, 8742-8749.


Successful matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) relies on the selection of the most appropriate matrix and optimization of the matrix application parameters. In order to achieve reproducible high spatial-resolution imaging data, several commercially available automated matrix application platforms have become available. However, the high cost of these commercial matrix sprayers is restricting access into this emerging research field. Here, we report an automated platform for matrix deposition, employing a converted commercially available 3D printer ($300) and other parts commonly found in an analytical chemistry lab alow-cost alternative to commercial sprayers. Using printed fluorescent rhodamine B microarrays and employing experimental design, the matrix deposition parameters were optimized to minimize surface analyte diffusion. Finally, the optimized matrix application method was applied to image three-dimensional MCF-7 cell culture spheroid sections (ca. 500 μm diameter tissue samples) and sections of mouse brain. Using this system, we demonstrate robust and reproducible observations of endogenous metabolite and steroid distributions with a high spatial resolution.

Tucker, Y.T., Mroz, T., 2018. Microbes in Marcellus Shale: Extremophiles living more than two kilometers inside the Earth? Fuel 234, 1205-1211.


Marcellus Shale drilling is a relatively new activity that has expanded natural gas resources in the United States. Although many assumed Marcellus Shale was sterile due to extreme conditions endured since deposition, conditions present in the shale today are within range where microorganisms can occur. Here, we consider whether some microbes seen in produced fluids from Marcellus Shale drilling may be native by comparing organisms found in core samples and produced fluids to those found in injected fluids from active wells in Pennsylvania. Illumina sequencing was used to identify organisms based on 16s rRNA barcoding regions of DNA extracts from Marcellus Shale samples. Identified microbial communities were then compared using principal components analysis and SourceTracker tools. Frequency of homology between sequences showed that produced fluids contained more microorganisms in common with shale cores than with injected fluids. Principal components analysis and SourceTracker corroborated these results. Possible native organisms found in these samples included radiotolerant extremophiles such as Deinococcus radiodurans. This work suggests that deep subsurface Marcellus Shale, previously believed sterile, may contain native microorganisms, which may have been deposited during the original deposition or migrated into the deep subsurface Marcellus during a more recent water influx. Additional investigation is recommended.

Uusitalo, J., Arppe, L., Hackman, T., Helama, S., Kovaltsov, G., Mielikäinen, K., Mäkinen, H., Nöjd, P., Palonen, V., Usoskin, I., Oinonen, M., 2018. Solar superstorm of AD 774 recorded subannually by Arctic tree rings. Nature Communications 9, Article 3495.

https://doi.org/10.1038/s41467-018-05883-1

Recently, a rapid increase in radiocarbon (14C) was observed in Japanese tree rings at AD 774/775. Various explanations for the anomaly have been offered, such as a supernova, a γ-ray burst, a cometary impact, or an exceptionally large Solar Particle Event (SPE). However, evidence of the origin and exact timing of the event remains incomplete. In particular, a key issue of latitudinal dependence of the 14C intensity has not been addressed yet. Here, we show that the event was most likely caused by the Sun and occurred during the spring of AD 774. Particularly, the event intensities from various locations show a strong correlation with the latitude, demonstrating a particle-induced 14C poleward increase, in accord with the solar origin of the event. Furthermore, both annual 14C data and carbon cycle modelling, and separate earlywood and latewood 14C measurements, confine the photosynthetic carbon fixation to around the midsummer.

Vagge, G., Cutroneo, L., Castellano, M., Canepa, G., Bertolotto, R.M., Capello, M., 2018. The effects of dredging and environmental conditions on concentrations of polycyclic aromatic hydrocarbons in the water column. Marine Pollution Bulletin 135, 704-713.

http://www.sciencedirect.com/science/article/pii/S0025326X1830571X

Sediment dredging can cause damage to the marine environment due to mobilization of sediments and contaminants. The effects of dredging and boundary environmental conditions on the concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in water were evaluated during dredging of the Oil Port of Genoa-Multedo (Italy). Results showed that turbidity and PAH concentrations increased in the water during dredging. However, the scenario was complex due to the high number of interacting physical-chemical factors influencing PAH concentrations and transport. Due to these, PAH distribution is different in water, where low-molecular-weight PAHs were predominant (maximum concentration 0.105 μg L−1), and in bottom sediments, where high-molecular-weight PAHs had the highest concentrations (from 299.3 to 1256.5 ng g−1). Moreover, mainly during dredging the PAH concentrations in water were significantly higher inside than outside the port as a consequence of the lower dynamics within the port basin. Turbidity was the main parameter related to PAH concentrations.

Valdespino-Castillo, P.M., Cerqueda-García, D., Espinosa, A.C., Batista, S., Merino-Ibarra, M., Taş, N., Alcántara-Hernández, R.J., Falcón, L.I., 2018. Microbial distribution and turnover in Antarctic microbial mats highlight the relevance of heterotrophic bacteria in low-nutrient environments. FEMS Microbiology Ecology 94, Article fiy129.


Maritime Antarctica has shown the highest increase in temperature in the Southern Hemisphere. Under this scenario, biogeochemical cycles may be altered, resulting in rapid environmental change for Antarctic biota. Microbes that drive biogeochemical cycles often form biofilms or microbial mats in continental meltwater environments. Limnetic microbial mats from the Fildes Peninsula were studied using high-throughput 16S rRNA gene sequencing. Mat samples were collected from 15 meltwater stream sites, comprising a natural gradient from ultraoligotrophic glacier flows to meltwater streams exposed to anthropogenic activities. Our analyses show that microbial community

structure differences between mats are explained by environmental NH4+, NO3

−, DIN, soluble reactive silicon and conductivity. Microbial mats living under ultraoligotrophic meltwater conditions did not exhibit a dominance of cyanobacterial photoautotrophs, as has been documented for other Antarctic limnetic microbial mats. Instead, ultraoligotrophic mat communities were characterized by the presence of microbes recognized as heterotrophs and photoheterotrophs. This suggests that microbial capabilities for recycling organic matter may be a key factor to dwell in ultra-low nutrient conditions. Our analyses show that phylotype level assemblages exhibit coupled distribution patterns in environmental oligotrophic inland waters. The evaluation of these microbes suggests the relevance of reproductive and structural strategies to pioneer these psychrophilic ultraoligotrophic environments.



This paper examines the hydrocarbon generation and storage potential of lithotypes, macerals, kerogen type relative to thermal maturity. To investigate authors had collected lithotype (vitrain, durain and fusain) samples from the high volatile sub-bituminous coal of Barjora area, SE of Raniganj coal basin, India. Relevant analyses viz. Rock Eval pyrolysis (REP), total organic carbon (TOC), micropetrography, vitrinite reflectance (Romv) and Fourier Transform Infrared Spectrometry (FTIR) were carried. The geochemical analysis indicates that the studied lithotypes have excellent potentiality of generating hydrocarbon in respect of TOC and S2 (under Rock-Eval pyrolysis) and it increases from vitrain to durain to fusain. Also, the free hydrocarbons which was recorded under S1 curve of Rock Eval pyrolysis, was observed to be highest within the fusain lithotype (21.73 mg HC/g rock). Further, the thermal maturity (Tmax: 418–423 °C) and mean vitrinite reflectance (Romv: 0.42–0.56%) indicate the samples are immature in nature. However, ↑Vt60 (vitrinite grains having a reflectance greater than 0.60%), indicates that thermogenic gas generation was occurring to some degree in almost all the samples. Moreover, comparison between geochemical and petrographical analysis it has been inferred that storing capability of hydrocarbons also increases from vitrain to durain to fusain. The higher capability of hydrocarbons within the fusain (in comparison to durain and vitrain) may be due to presence of large amount of fusinite and semifusinite macerals. The production index (PI) also shows similar trend with increasing S1 value. The FTIR study demonstrates that the fusain has higher intensity of aliphaticity than that of vitrain and durain. The higher intensity of aliphaticity in the fusain may be due to presence of considerable amount of bituminite and other liptinites within the cavities/cell lumens. All the observation suggests that fusain has the highest hydrocarbon generation and storage potentiality, whereas durain has less and vitrain has least generation potentiality in comparison to fusain.

Vasilenko, P.A., Kornienko, S.G., Primerova, O.V., 2018. IR spectrometric determination of weight fractions of oil and gas condensate in products oil and gas condensate wells. Journal of Analytical Chemistry 73, 777-785.

https://doi.org/10.1134/S1061934818080099

A method of the IR spectrometric determination of weight fractions of oil and gas condensate in the production of oil and gas condensate wells is proposed. The features of infrared spectra of the integrated absorbance of hydrocarbon solutions, recorded using a Fourier-transform IR spectrometer and an IKAR-3 scanning IR spectrometer, are discussed.

Verweij, J.M., Nelskamp, S.N., Ten Veen, J.H., De Bruin, G., Geel, K., Donders, T.H., 2018. Generation, migration, entrapment and leakage of microbial gas in the Dutch part of the Southern North Sea Delta. Marine and Petroleum Geology 97, 493-516.


Understanding the shallow gas system is critical for assessing its potential as an energy source, for evaluating the possible hazard of shallow gas for drilling and wind farm locations and for evaluating the effect of gas emissions at the seabed on marine ecosystems and climate. This paper presents the key elements and processes of the microbial shallow gas system in the Plio-Pleistocene Dutch Southern North Sea Delta based on recent findings from different projects. Geochemical and carbon isotopic composition of shallow gas occurrences in the delta are indicative of a microbial origin of the gas. Shallow gas mainly occurs in stratigraphic traps and stacked anticlinal structures above salt structures, as indicated by identified direct hydrocarbon indicators on seismic, such as bright spots. Organic matter in the delta deposits is of predominantly land plant origin with TOC values varying between <1% and 5%, and mostly between 1 and 2%. Simulations of temperature and burial history in combination with dedicated 1D simulations of microbial gas generation reveal that gas generation in the delta started in Early Pleistocene Calabrian times and is still ongoing. Simulated volumes of gas generation are more than enough to fill published estimated volumes of shallow gas prospects in the delta. The geometry of the E-W prograding delta sequences and the close interbedding of interglacial silty/sandy and glacial clayey/silty sediments focus gas migration updip through the foresets towards the topsets of the delta sequences, and ultimately into the anticlinal stacked traps. Grain-size based calculations of the permeability and capillary seal capacity of clayey/silty seals of the stratigraphic and anticlinal traps provided first estimates of permeability values ranging from 2.8E-20 m2 to 1.1E-18 m2 and capillary seal capacity values between 10m and 24m. Comparison of gas column heights derived from grain-size based calculations, cross plots of neutron and density logs and pressure measurements, with trap heights derived from seismic bright spots suggests that many traps in stacked bright spots are not filled to structural spill point. This suggests that filling of the stacked reservoirs is not related to fill-spill migration, but rather to leakage through the top seal. In absence of fault and fracture zones crossing the seal, this leakage is related to the capillary seal capacity and permeability of the top seal. The leakage extends, locally, to the seabed.

The microbial gas system in the delta today is a highly dynamic system driven by ongoing burial of the delta sediments and microbial gas generation.

Vogel, G., 2018. Ancient DNA reveals tryst between extinct human species. Science 361, 737.


The woman may have been just a teenager when she died more than 50,000 years ago, too young to have left much of a mark on her world. But a piece of one of her bones, unearthed in a cave in Russia's Denisova valley in 2012, may make her famous. Enough ancient DNA lingered within the 2-centimeter fragment to reveal her startling ancestry: She was the direct offspring of two different species of ancient humans—neither of them ours. An analysis of the woman's genome, reported in this week's issue of Nature, indicates her mother was Neanderthal and her father was Denisovan, the mysterious group of ancient humans discovered in the same Siberian cave in 2011. It is the most direct evidence yet that various ancient humans mated with each other and had offspring.

Based on other ancient genomes, researchers already had concluded that Denisovans, Neanderthals, and modern humans interbred in ice age Europe and Asia. The genes of both archaic human species are present in many people today. Other fossils found in the Siberian cave have shown that all three

species lived there at different times. But the new finding “is sensational” just the same, says Johannes Krause, who studies ancient DNA at the Max Planck Institute for the Science of Human History in Jena, Germany. “Now we have the love child of two different hominin groups, found where members of both groups have been found. It's quite a lot of things happening in one cave through time.”

Viviane Slon, a paleogeneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who did the ancient DNA analysis, says when she saw the results, her first reaction was disbelief. Only after repeating the experiment several times were she and her Leipzig colleagues—Svante Pääbo, Fabrizio Mafessoni, and Benjamin Vernot—convinced. That a direct offspring of the two ancient humans was found among the first few fossil genomes recovered from the cave suggests, Pääbo says, “that when these groups met, they actually mixed quite freely with each other.”

The bone fragment's characteristics suggested it came from someone who was at least 13 years old. After pulverizing small samples, extracting DNA, and sequencing it, Slon and her colleagues found that its owner was female, and that her genome matched that of Denisovans and Neanderthals in roughly equal measure. Moreover, the proportion of genes in which her chromosome pairs harbored different variants—so-called heterozygous alleles—was close to 50% across all chromosomes, suggesting the maternal and paternal chromosomes came directly from different groups. And her mitochondrial DNA, which is inherited maternally, was uniformly Neanderthal, so the researchers concluded she was a first-generation hybrid of a Denisovan man and Neanderthal woman. The evidence “is so direct, we almost caught them in the act,” Pääbo says.

A closer look at the genome suggests her father also had some Neanderthal ancestry, possibly several hundred generations back. And the woman's Neanderthal genes are closer to those of a Neanderthal found in Croatia than those from remains found in the Siberian cave. That suggests distinct groups of Neanderthals migrated back and forth between western Europe and Siberia multiple times.

Along the way, apparently, they freely spread their genes to outsiders. That highlights the question, Krause says, of why Denisovans and Neanderthals nevertheless remained genetically distinct groups. “Why don't they come together as one population if they come together from time to time?” Geographic barriers probably played a role, he says, but researchers need more fossils with ancient DNA, from multiple sites, to understand the true legacy of these prehistoric couplings.

von der Lühe, B., Birk, J.J., Dawson, L., Mayes, R.W., Fiedler, S., 2018. Steroid fingerprints: Efficient biomarkers of human decomposition fluids in soil. Organic Geochemistry 124, 228-237.


The decomposition of animal and human cadavers can lead to comprehensive chemical and biochemical changes in soil, which can provide helpful information for the analysis of archaeological and crime scenes. The current study focused specifically on the concentration and distribution patterns of steroids in soil with the aim of assessing their suitability for demonstrating the presence of human decomposition products. Soil samples were collected from a forensic site where a human corpse had been lying on the soil surface for 18 days. Total organic carbon (TOC) and steroid concentrations were analysed in soil samples taken from beneath the body at the time the corpse was removed and also one year later. High concentrations of TOC and steroids were detected close to the soil surface at the time the body was removed, and the concentration of cadaver-derived cholesterol was considerably higher than that of the plant-derived sitosterol. The soil beneath the cadaver contained higher concentrations of faeces-derived 5β-stanol coprostanol than the control soil. Different concentrations and distribution patterns of steroid compounds in the soil upon removal of

the corpse and one year later indicate that significant transformation, degradation and translocation processes had taken place during this period of time. The depth distribution of steroids beneath a decomposing body along with changes in the human steroidal fingerprints in soil over time were found to provide information that could help resolve forensic and archaeological issues. The combined analysis of tissue steroids (cholesterol), the reduction product of cholesterol in soil (5α-cholestanol) as well as faecal steroids (coprostanol, 5β-stigmastanol and their conversion products epicoprostanol and epi-5β-stigmastanol) represent excellent additions to the forensic toolbox for determining whether a soil of interest has ever been affected by a human cadaver or not.

Walasek, N., Loydell, D.K., Frýda, J., Männik, P., Loveridge, R.F., 2018. Integrated graptolite-conodont biostratigraphy and organic carbon chemostratigraphy of the Llandovery of Kallholn quarry, Dalarna, Sweden. Palaeogeography, Palaeoclimatology, Palaeoecology 508, 1-16.


A revised graptolite and conodont biostratigraphy together with new organic carbon isotope data for the middle Aeronian to lower Telychian (Llandovery, lower Silurian) of Kallholn quarry, central Sweden, are presented. The base of the section is marked by an unconformity between the Ordovician Boda Limestone and Aeronian shales with limestone nodules belonging to the Pribylograptus leptotheca Biozone. These are overlain by strata assigned to the lower Lituigraptus convolutus Biozone. The Stimulograptus sedgwickii Biozone, previously recorded from the section, is absent and marked by an unconformity which is overlain by radiolarian-rich graptolitic shales belonging to the Stimulograptus halli Biozone. The overlying Telychian strata are assigned to the Spirograptus guerichi, Spirograptus turriculatus and Streptograptus crispus biozones. Conodonts indicate that the boundary between the Distomodus staurognathoides Biozone and Pterospathodus eopennatus Superzone lies within the Sp.turriculatus Biozone, as it does also in the Ohesaare core, Estonia. The δ13Corg record shows mostly minor fluctuations but with a distinct twin-peaked positive excursion in the upper Sp.turriculatus Biozone, close to the boundary with the overlying Streptograptus crispus Biozone. The excursion in the Kallholn section may correlate with the earliest positive shift in δ13C values at the onset of the excursion associated with the Valgu Event or it may represent a new excursion (provisionally named the Kallholn excursion) preceding this. Many more bentonites (36) occur in the section than previously recorded – geochemical studies are needed to confirm whether the Osmundsberg bentonite (which may or may not be equivalent to the “O” bed in Estonia and Latvia) is present.

Walter Anthony, K., Schneider von Deimling, T., Nitze, I., Frolking, S., Emond, A., Daanen, R., Anthony, P., Lindgren, P., Jones, B., Grosse, G., 2018. 21st-century modeled permafrost carbon emissions accelerated by abrupt thaw beneath lakes. Nature Communications 9, Article 3262.

https://doi.org/10.1038/s41467-018-05738-9

Permafrost carbon feedback (PCF) modeling has focused on gradual thaw of near-surface permafrost leading to enhanced carbon dioxide and methane emissions that accelerate global climate warming. These state-of-the-art land models have yet to incorporate deeper, abrupt thaw in the PCF. Here we use model data, supported by field observations, radiocarbon dating, and remote sensing, to show that methane and carbon dioxide emissions from abrupt thaw beneath thermokarst lakes will more than double radiative forcing from circumpolar permafrost-soil carbon fluxes this century. Abrupt thaw lake emissions are similar under moderate and high representative concentration pathways (RCP4.5 and RCP8.5), but their relative contribution to the PCF is much larger under the moderate warming scenario. Abrupt thaw accelerates mobilization of deeply frozen, ancient carbon, increasing 14C-

depleted permafrost soil carbon emissions by ~125–190% compared to gradual thaw alone. These findings demonstrate the need to incorporate abrupt thaw processes in earth system models for more comprehensive projection of the PCF this century.

Walters, C.C., Peters, K.E., Moldowan, J.M., 2018. History of life from the hydrocarbon fossil record, in: Wilkes, H. (Ed.), Hydrocarbons, Oils and Lipids: Diversity, Origin, Chemistry and Fate. Springer International Publishing, pp. 1-35.

https://doi.org/10.1007/978-3-319-54529-5_32-1

Petroleum, one of the most complex organic mixtures in nature, is derived from biochemicals deposited in sediments that are then buried and thermally altered. Petroleomics aims at a complete molecular description of petroleum, the petroleome, from which all physical properties – such as density, viscosity, phase behavior, and interfacial activity – and chemical reactivity – such as reservoir alteration and refinery upgrading processes – could be modeled. Although petroleomics has its roots in decades of petroleum chemical characterization, its modern conception is less than 20 years old. It is only through recent analytical advances, such as ultrahigh-resolution mass spectrometry, that an approximation of the petroleome is possible. The ability to use the petroleome to predict physical properties and chemical reactivity is just emerging.

Walters, C.C., Wang, F.C., Higgins, M.B., Madincea, M.E., 2018. Universal Biomarker Analysis: Aromatic hydrocarbons. Organic Geochemistry 124, 205-214.


Universal Biomarker Analysis is a GC×GC-ToFMS method that provides absolute quantification and non-targeted pseudo MS-MS for all resolved hydrocarbon components in petroleum and rock extracts. This is achieved by merging two chromatographic datasets obtained under field ionization (FI), which provides molecular ions, and electron impact (EI), which provides diagnostic fragment ions. We recently demonstrated this technique for the analysis of saturated biomarkers (Walters et al., 2018). Here, we show its application to aromatic biomarkers. Universal Biomarker Analysis is compared to conventional GC–MS for frequently analyzed aromatic hydrocarbons, such as the alkylated naphthalenes and biphenyls, mono- and tri-aromatic steroidal hydrocarbons to illustrate where this new method provides demonstrated advantages. The technique is well suited for the analysis of rare species not commonly analyzed in targeted GC–MS/MS analyses. This is illustrated by the tentative identification of A/B-ring C26-C29 diaromatic steroidal hydrocarbons in a crude oil, compounds that have been previously identified as minor components of immature rock extracts, and indications of previously unknown C26 methyl-triaromatic steroidal hydrocarbons.

Wan, T., Liu, H.-X., 2018. Exploitation of fractured shale oil resources by cyclic CO2 injection. Petroleum Science 15, 552-563.

https://doi.org/10.1007/s12182-018-0226-1

With shale oil reservoir pressure depletion and recovery of hydrocarbons from formations, the fracture apertures and conductivity are subject to reduction due to the interaction between stress effects and proppants. Suppose most of the proppants were concentrated in dominant fractures rather than sparsely allocated in the fracture network, the fracture conductivity would be less influenced by the induced stress effect. However, the merit of uniformly distributed proppants in the fracture network is that it increases the contact area for the injection gas with the shale matrix. In this paper,

we address the question whether we should exploit or confine the fracture complexity for CO2-EOR in shale oil reservoirs. Two proppant transport scenarios were simulated in this paper: Case 1—the proppant is uniformly distributed in the complex fracture system, propagating a partially propped or un-propped fracture network; Case 2—the proppant primarily settles in simple planar fractures. A series of sensitivity studies of the fracture conductivity were performed to investigate the conductivity requirements in order to more efficiently produce from the shale reservoirs. Our simulation results in this paper show the potential of CO2 huff-n-puff to improve oil recovery in shale oil reservoirs. Simulation results indicate that the ultra-low permeability shales require an interconnected fracture network to maximize shale oil recovery in a reasonable time period. The well productivity of a fracture network with a conductivity of 4 mD ft achieves a better performance than that of planar fractures with an infinite conductivity. However, when the conductivity of fracture networks is inadequate, the planar fracture treatment design maybe a favorable choice. The available literature provides limited information on the relationship between fracture treatment design and the applicability of CO2 huff-n-puff in very low permeability shale formations. Very limited field test or laboratory data are available on the investigation of conductivity requirements for cyclic CO2 injection in shale oil reservoirs. In the context of CO2 huff-n-puff EOR, the effect of fracture complexity on well productivity was examined by simulation approaches.

Wang, D., Sun, S., Sha, T., Liu, T., Dong, H., Cui, K., Li, H., Gong, Y., Hou, J., Zhang, Z., Fu, P., 2018. Synergistic effect of silica nanoparticles and rhamnolipid on wettability alteration of low permeability sandstone rocks. Energy & Fuels 32, 8098-8107.


Wettability modification is one of the main mechanisms to increase oil recovery from low-permeability oil reservoirs. Nanofluids composed of nanoparticles can be used as modifiers to alter wettability from oil-wet to water-wet condition thus to promote hydrocarbon recovery. Biosurfactants, which are candidates to replace synthetic surfactants for industrial applications, have the potential to prepare nanofluids. In this study, nanofluids prepared by dispersing SiO2 nanoparticles in rhamnolipid solution (hereby named bionanofluids) were considered potential wettability modifiers to apply to petroleum recovery from low-permeability sandstone reservoirs. Analyses via visual observation, optical absorbance measurement, ζ-potential determination, and particle size measurements demonstrated that the bionanofluids with 25 ppm rhamnolipids maintained an optimal stability. The effect of bionanofluids on wettability alteration was investigated through contact angle measurement and imbibition test. The results showed that bionanofluids could alter the wettability of oil-wet sandstone to strongly water-wet. The best performance was achieved with a nanoparticle concentration of 1000 ppm. Additionally, a micromodel test using rhamnolipid solution and bionanofluid was carried out to evaluate the synergistic effects of SiO2 nanoparticles and rhamnolipid on displacing oil. Bionanofluid injection following biosurfactant flooding was shown to improve oil recovery, yielding an additional 5% production. These results reveal that the bionanofluid prepared with SiO2 and rhamnolipids not only remained stable but also provided a potential way for enhanced oil recovery.

Wang, F., Dong, X., Fan, X., Zhao, Y.-P., Li, G.-S., Wang, C.-F., Wei, X.-Y., Ma, F.-Y., Zhong, M., 2018. In-source collision activated dissociation for coal/biomass-based model compounds and structural characterization of a coal extract. Fuel 234, 1033-1043.


In-source collision activated dissociation (ISCAD) is an effective method to obtain molecular structure of coal and biomass and provide basic knowledge for coal/biomass conversion. Twenty two coal/biomass-based model compounds and one coal extract were studied via ISCAD to understand the relationship between collision energy and molecular structure and the application of ISCAD in the characterization of coal. Model compounds showed different fragmentation patterns with the increase of collision energy and the detailed fragmentation pathways in context of collision energies were proposed. According to the ISCAD results of coal extract, the weighted mean molecular weight (MW) and weighted mean double-bond equivalent (DBE) values of ionized coal molecules decreased over collision energy of 80 eV. The decrease of weighted mean MW and DBE were mainly caused by the cleavage of alkyl chains, bridged bonds, and minor cracking of small aromatic cores from precursor ions upon fragmentation. Therefore, the optimal ISCAD collision energy for the investigation of aromatic core structures of the coal extract should be around 80 eV.

Wang, G., Zhong, L., Zhou, S., Liu, Q., Li, Q., Fu, Q., Wang, L., Huang, R., Wang, G., Li, X., 2018. Jet breaking tools for natural gas hydrate exploitation and their support technologies. Natural Gas Industry B 5, 312-318.


Marine natural gas hydrate (NGH) reservoirs in China are characterized by shallow burial depth and weak cementing. In view of these characteristics, it is in an urgent need to develop a series of technologies and support tools to ensure safe, economical, green and efficient NGH exploitation. In this paper, a new technical idea of NGH jet breaking and fluidization exploitation without changing the temperature and pressure conditions of NGH reservoirs was proposed, and the support nozzle tools for NGH jet breaking was designed, experimentally tested and optimized. Then, the relationships between the jet breaking parameters of nozzles (e.g. working pressure drop, flow rate, and lifting and lowering velocity and frequency) and the borehole diameters and breaking rates of broken NGH were investigated based on laboratory tests, and the field construction engineering charts of NGH jet breaking and fluidization exploitation were established. Finally, this method was practically verified at Well Liwan 3 in the South China Sea. And following research results were obtained. First, the NGH jet breaking and fluidization exploitation technology can increase the production efficiency of NGH exploitation, protect the safety of reservoir bottom and reduce the energy consumption of NGH exploitation. Second, by using the nozzle tools of NGH jet breaking, the generated borehole diameters are regular, broken particles can flow back well, and the lowering velocity of jet breaking without pilot holes is less than 7.1 m/h. Third, the engineering charts of NGH jet breaking and fluidization exploitation interpret the influential laws of jet breaking behaviors and construction parameters on the borehole diameters and breaking rates of NGH so as to provide a reference for the selection of NGH production test technology parameters. And fourth, the successful implementation of the NGH jet breaking and fluidization technology in the production tests of Well Liwan 3 verifies the feasibility of NGH jet breaking and fluidization exploitation process, and exhibits its promising application prospects in NGH future commercial exploitation.

Wang, H., Luo, M., Lun, Z., Lv, C., Zhao, C., Zhao, Q., Lang, D., 2018. Determination and comparison of interfacial interactions between CO2, crude oil, and brine at reservoir conditions. Energy & Fuels 32, 8187-8192.


Axisymmetric drop shape analysis (ADSA) has been applied to study the interfacial interactions of CO2 and reservoir fluid systems at elevated pressures and high temperatures. Using ADSA for the

pendant drop technique, it was possible to determine the interfacial tension (IFT) and visualize the interfacial interaction phenomenon of CO2/crude oil, CO2/brine, crude oil/brine, and crude oil/CO2-saturated brine systems under actual reservoir conditions. (1) For the CO2/crude oil system, there was a light component extraction and initial turbulent mixing when crude oil contacted CO2. The interfacial interaction between CO2 and crude oil increased and the IFT of the CO2/crude oil system decreased as pressure increased. (2) For the CO2/brine system, the wettability between brine and needle surfaces was altered from hydrophilicity to hydrophobicity as pressure increased and CO2 changed from a gas state to a supercritical state. The IFT of the CO2/brine system decreased as pressure increased. (3) For the crude oil/CO2-saturated brine system, there were not interfacial interactions similar to those of the CO2/crude oil system. The interface of the crude oil/CO2-saturated brine system was as clear as that of crude oil/brine. The IFT of the crude oil/CO2-saturated brine system was slightly lower than that of crude oil/brine due to CO2 dissolution. For the IFT of the four systems, that of CO2/crude oil was the lowest, while those of CO2/brine, crude oil/brine, and crude oil/CO2-saturated brine systems were similar.

Wang, J., Liang, J., Gao, S., 2018. Biodegradation of lignin monomers vanillic, p-coumaric, and syringic acid by the bacterial strain, Sphingobacterium sp. HY-H. Current Microbiology 75, 1156-1164.

https://doi.org/10.1007/s00284-018-1504-2

Many bacterial strains have been demonstrated to biodegrade lignin for contaminant removal or resource regeneration. The goal of this study was to investigate the biodegradation amount and associated pathways of three lignin monomers, vanillic, p-coumaric, and syringic acid by strain Sphingobacterium sp. HY-H. Vanillic, p-coumaric, and syringic acid degradation with strain HY-H was estimated as 88.71, 76.67, and 72.78%, respectively, after 96 h. Correspondingly, the same three monomers were associated with a COD removal efficiency of 87.30, 55.17, and 67.23%, and a TOC removal efficiency of 82.14, 61.03, and 43.86%. The results of GC–MS, HPLC, FTIR, and enzyme activities show that guaiacol and o-dihydroxybenzene are key intermediate metabolites of the vanillic acid and syringic acid degradation. p-Hydroxybenzoic acid is an important intermediate metabolite for p-coumaric and syringic acid degradation. LiP and MnP play an important role in the degradation of lignin monomers and their intermediate metabolites. One possible pathway is that strain HY-H degrades lignin monomers into guaiacol (through decarboxylic and demethoxy reaction) or p-hydroxybenzoic acid (through side-chain oxidation); then guaiacol demethylates to o-dihydroxybenzene. The p-hydroxybenzoic acid and o-dihydroxybenzene are futher through ring cleavage reaction to form small molecule acids (butyric, valproic, oxalic acid, and propionic acid) and alcohols (ethanol and ethanediol), then these acids and alcohols are finally decomposed into CO2 and H2O through the tricarboxylic acid cycle. If properly optimized and controlled, the strain HY-H may play a role in breaking down lignin-related compounds for biofuel and chemical production.

Wang, J., Wang, Z., Liu, F., Cai, L., Pan, J.-b., Li, Z., Zhang, S., Chen, H.-Y., Zhang, X., Mo, Y., 2018. Vacuum ultraviolet laser desorption/ionization mass spectrometry imaging of single cells with submicron craters. Analytical Chemistry 90, 10009-10015.


Mass spectrometry imaging (MSI) is a crucial label-free method to distinguish the localization patterns in single cells. MALDI-TOF MS and ToF-SIMS are now bearing the responsibility. However, MALDI-TOF MS is limited to micron spatial resolution and ToF-SIMS suffers from severe molecular fragmentation. Here, we proposed a new MSI methodology of vacuum ultraviolet laser desorption/ionization (VUVDI) with high spatial resolution, achieving higher ion yields and less

fragmentation compared with ToF-SIMS at submicron level. The fluorescence image and mass spectrum of VUVDI were obtained simultaneously. In addition, the adjustable laser fluence acquired selective detection for different molecular and fragmental ions, thus realizing molecular identification. Furthermore, MSIs of single cells with submicron craters were presented. These results suggest VUVDI is a potential mass spectrometry method that provides a soft ionization source and submicron spatial resolution for molecular analysis in life science.

Wang, J., Wang, Z., Sun, B., Gao, Y., Wang, X., Fu, W., 2019. Optimization design of hydraulic parameters for supercritical CO2 fracturing in unconventional gas reservoir. Fuel 235, 795-809.


Unconventional gas reservoirs are characterized by ultra-low permeability. Such ultra-low permeability can significantly affect the geometry of the fractures being created in the reservoir, as well as bring about challenges with regard to how to effectively mitigate formation damage issues during fracturing. Supercritical CO2 (SC-CO2) fracturing, as an innovative and promising stimulation method, incurs no formation damage, and is capable of effectively improving the reservoir permeability, preventing near-wellbore formation blockage. Taking the effects of adsorption between CO2-shale-CH4 into consideration, a two-phase filtration rate calculation model of SC-CO2 fracturing in unconventional natural gas reservoirs is proposed. Based on physical property equations of a SC-CO2 fluid, and considering the internal fluid energy, the change in flow work, and the filtration and adsorption characteristics of SC-CO2-shale, temperature and pressure field models were built inside the wellbore and fracture of SC-CO2 fracturing, as was a two-phase flow model of SC-CO2 fracturing fluid carrying proppant in a fracture under an unsteady state. The calculation results show that the temperature and pressure of the fracturing fluid in the wellbore increase with the depth of the well. The temperature of the SC-CO2 fluid in the fracture increases with the increase in fracture length, and eventually reaches close to the original formation temperature, whereas the pressure of fluid CO2 in the fracture decreases with an increase in the fracture length. The hydraulic parameters of SC-CO2 fracturing are optimized, such as the CO2 injection temperature, pumping rate, proppant density, and diameter. According to the proppant embankment profile, the method of increasing the proppant concentration in small steps and the optimization of the proppant pumping process satisfy the fracture propping requirements.

Wang, P., Zou, C., Li, X., Jiang, L., Li, J., Mei, J., Zhang, Z., Li, Q., 2018. Main geological controlling factors of shale gas enrichment and high yield in Zhaotong demonstration area. Acta Petrolei Sinica 39, 744-753.

http://www.syxb-cps.com.cn/EN/abstract/abstract5509.shtml

Zhaotong shale gas demonstration area is characterized by "strong transformation, over-maturity and complex stress", where the control factors of shale gas accumulation and high yield are complicated. To achieve the large-scale highly-efficient shale gas exploration and development, based on the previous understanding of southern marine shale gas enrichment law, the actual exploration and development data of Zhaotong shale gas demonstration area are used to systematically summarize the main geological controlling factors for the enrichment and high yield of Zhaotong shale gas field. It is considered that (1)the carbon-rich high-silicon shale in transgressive system tract provides a material basis for shale gas enrichment. The oxygen-poor and anaerobic environment in transgressive system tract is characterized by slow deposition rate and rich siliceous life, which is conducive to the formation and preservation of organic-rich shale. For the carbon and silicon-rich shale (Wufeng

Formation-Sublayer 3, Sub-member 1, Member 1 of Longmaxi Formation)in the transgressive system tract, organic pores and micro-fissures are developed with strong adsorption capacity and gas-bearing capacity as well as favorable compressibility. (2)The key to gas enrichment and high yield is the proper post-structural transformation and the effective preservation of high-pressure sealed box. The Mesozoic synclinorium in the northern Zhaotong demonstration zone is located in the tectonic transformation belt with moderate reform intensity. The maximum principal stresses in three directions are converged to the synclinorium groove with the development of mesh fissures and the advantage of hybrid accumulation mode. In the early stage, the high-pressure sealed box is formed under good roof and bottom sealing conditions, which is preserved effectively in the later moderate uplift. In Zhaotong demonstration zone, the dual-controlling factors of gas enrichment are taken as the guidance to optimize the Sublayers 1-2, Sub-member 1, Longmaxi Formation as sweet spot horizons, of which the north Huangjinba, Zijinba, Yunshanba and Dazhai blocks are shale-gas enrichment regions. The tectonic transformation intensities are different in late period, leading to the difference in the shale gas enrichment and high yield of sweet spot areas at different tectonic locations.

Wang, Q., Puerto, M.C., Warudkar, S., Buehler, J., Biswal, S.L., 2018. Recyclable amine-functionalized magnetic nanoparticles for efficient demulsification of crude oil-in-water emulsions. Environmental Science: Water Research & Technology.

http://dx.doi.org/10.1039/C8EW00188J

Produced water from the oil and gas industry often contains stable crude oil-in-water emulsions that are typically difficult to treat with conventional separation methods. Amine-functionalized nanoparticles have demonstrated effective destabilization of crude oil-in-water emulsions by associating with natural surfactants present at the oil–water interface leading to separation of oil from water under an external magnetic field. Effects of magnetic demulsifier concentration, reaction time and initial oil content of emulsion on the demulsification efficiency were investigated. The demulsification efficiency of emulsions can reach as high as 99.7% by the magnetic demulsifier. Our findings characterize the demulsification process as a function of nanoparticle concentration and elucidate the governing interactions between NH2-MNPs and emulsion droplets. Another important feature of this magnetic demulsifier is its capability to be recovered by solvent-washing and reused for subsequent demulsification cycles. The recovered magnetic demulsifier was proven to be effective in demulsifying O/W emulsion for at least 6 cycles, revealing its recyclability. Demulsification of O/W emulsions with NH2-MNPs has great potential as an efficient strategy for oil removal from produced water.

Wang, Q., Qin, Y., Jia, W., Wang, Y., Zhang, W., Peng, P.a., 2018. Density and viscosity of tight oil from Yanchang Formation, Ordos Basin, China and the geochemical controls. Petroleum Science and Technology 36, 1298-1304.

https://doi.org/10.1080/10916466.2018.1471495

For assessing the density and viscosity of tight oil and their geochemical controls, 47 tight oil samples across the Ordos Basin were analyzed. The oil density and viscosity lay in the ranges of 0.81?0.88 g/ml and 1.9?13.36 mPa·s, which are low in overall. The average saturated hydrocarbon content is higher than 80%. The molecular compositions suggest a source dominated organic matter by lacustrine type I/II with minor input of terrestrial type III kerogen. The oils were mainly generated at relatively high maturities. Fractionation during the oil expulsion may also result in the depletion of

heavy-ends compounds. These are the main controlling factors for the overall good quality of the Ordos tight oil.

Wang, S.-K., Wei, X.-Y., Li, S., Liu, F.-J., Wang, Y.-G., Li, Z.-K., Shi, C., Yang, Z., Zong, Z.-M., 2018. Rapid analysis of carboxylic acids and esters with a direct analysis in real time ion source. Rapid Communications in Mass Spectrometry 32, 1521-1528.

https://doi.org/10.1002/rcm.8156

Rationale: Coal oxidation produces carboxylic acids (CAs), including aliphatic acids, benzoic acids, and benzenepolycarboxylic acids, which are important fine chemicals which could be used to understand the structural features of coals. However, detecting CAs usually presents great challenges due to extremely troublesome pretreatments. Therefore, it is essential to develop an analytical method for the rapid detection of CAs from coal oxidation.

Methods: A series of model compounds (MCs) of oxidation products and two practical samples were investigated by direct analysis in real time time‐of‐flight mass spectrometry (DART‐TOFMS) under three different analytical conditions (ionizing gas temperature, organic solvent, and MC concentration).

Results: Ionizing methyl benzoate, dimethyl phthalate, and dimethyl adipate produces typical ions of methyl esters, including [M − OCH3]+, [M + H]+, and [M + NH4]+. In contrast, the characteristic ions generated from CAs are polymer ions, such as [2 M + NH4]+, [3 M + NH4]+, [4 M + NH4]+, and [5 M + NH4]+, indicating the strong intermolecular hydrogen‐bond interaction among CAs.

Conclusions: Results suggest that DART‐TOFMS could rapidly analyze CAs or esters in coal oxidation products according to their typical ions to further gain deep insights into the coal structure.



Numerical flow simulation in shale, especially in the nanoscale porous system of a shale matrix, is still challenging because no imaging device can effectively describe the nanoscale porous structure of shale to satisfy both resolution and field of view (FOV). The resolution of an X-ray computed tomography (µ-CT) image is too low to detect the nanoscale features of porous structure in shale. The FOV of a focused ion beam scanning electron microcopy (FIB-SEM) image, on the other hand, is too small to capture the heterogeneity of a shale matrix. Therefore, we propose a semi-quantitative, Multiscale reconstruction strategy to build an image based network model of a shale sample with nanoscale resolution covering three orders of magnitude of FIB-SEM image volume. In this study, shale is considered a Multiscale porous media consisting of microscale and nanoscale structures. The microscale structures reflect the morphological features of organic matter, clay minerals, intergranular pores and micro-cracks that can be detected by µ-CT. The nanoscale features focus on the inner porous structure of organic matter and clay minerals that can be characterised using a scanning electron microcopy (SEM) or a FIB-SEM. nanoscale. Multiscale means reconstruction work that is carried out at the microscale and nanoscale separately, using the multiple-point statistics (MPS) method. Microscale reconstruction aims to recover the connections that are undetected among microscale objects due to the low resolution of the µ-CT image. Within the organic and clay phases, a nanoscale reconstruction is then carried out to model the nanoscale porous structure. Semi-quantitative means the segmented µ-CT image is used as conditional data in microscale

reconstruction to maintain the reality of microscale structures. To relieve the heavy burden of data storage, a network modelling procedure is simultaneously undertaken alongside nanoscale reconstruction to transfer the reconstructed structure to a network model. Based on the established network model, flow simulation is undertaken by applying an extended Beskok-Karniadakis (B–K) model considering continuum, non-continuum and surface diffusion. The results show that the permeability ratio is affected by pressure, the molecule diameter of gas and surface diffusion.



Aboundant authigene carbonate minerals and iron sulfide in sea-bed methane cold seeps are important geologic markers to prospect natural gas hydrate(NGH). However, there are very limited experimental researches on their formation conditions. The aquantic chemical changes of water systems with sulfate reducing bacteria and anaerobic methanotrophic archaea under various temperatures and pressures were simulated and investigated as the first time by using a home-made sealed bioreactor system. Minerals morphology, carbonate species and iron sulfide under different temperatures and pressures were checked using scanning electron microscope (SEM) and X-ray diffraction (XRD) to study on their precipitation regulation. For the experiments under 5 , 8 and ℃ ℃10 , the pH values and concentrations of HCO℃ 3

- were in ranges of 6.5-7.4 and 202.55-639.93 mg/L, respectively. The oxidation-reduction potential (ORP) stayed near -100.0 mV. For the experiments under 2.5 MPa, 5.0 MPa and 7.5 MPa, the pH values and concentrations of HCO3

- were in range of 6.1-7.2 and 324.08-789.95 mg/L, respectively. The oxidation-reduction potential (ORP) was remained from -100 mV to -50.0 mV. These experimental results demonstrated that temperature and pressure might control authigene carbonate minerals formation by influence of microbial metabolism to provide the source for S2- and HCO3

-, which were able to form the minerals combined with cations. Calcite, siderite and iron sulfide were precipitated in all experiments whereas the HCO3

- concentration was diminishing, the S2- concentration was rised and ORP decreased when the temperature was increased. The distribution of siderite and iron sulfide was increasing with temperature and S2- concentration, probably indicating that increasing temperature could facilitate the formation of iron sulfide and siderite. The S2- produced by microbes metabolism and negative values of ORP(below 0) were decreasing along with increasing pressure. Simultaneously, carbonate formation was increased and the distribution range of iron sulfide became wider and also better in morphology. The decrease of calcium carbonate precipitation might be controlled by the concentration of S2-. These results could be significant to provide insights into the storage and cycle of carbon and sulfur, and the formation mechanism of authigene minerals in global ocean.

Wei, N., Xu, H., Sun, W., Zhao, J., Zhang, L., Fu, Q., Pang, W., Zheng, L., Lü, X., 2018. Migration laws of natural gas hydrate solid particles with different abundance in horizontal wells. Natural Gas Industry B 5, 306-311.


When a horizontal well is drilled through the natural gas hydrate (NGH) strata with different abundance, the NGH-bearing solid debris tends to lead to the deposit and adhesion of solid particles in the lateral sections and consequently cuttings carrying is not smooth. In this paper, the critical return rate model of drilling fluid in the case of cuttings rolling (normal drilling) and saltation (pump off for sand settling) under NGH adhesion in the laterals was established according to the force and

migration laws of cuttings under the condition of multiphase flow in a horizontal well and the particle migration theory. Then, numerical simulation was conducted and the influential factors and migration laws of cuttings starting in the case of normal drilling and pump off were analyzed. And the following results were obtained. First, the critical starting flow rate decreases with the rise of NGH abundance and it is higher when the NGH adhesion is taken into account. Besides, the higher the NGH abundance, the greater the effect of NGH adhesion. Second, the critical starting flow rate increases with the rise of drilling cuttings particle size when the NGH abundance is less than 85%; and it decreases with the rise of drilling cuttings particle size when the NGH abundance is more than 85%. Third, the critical starting flow rate decreases with the rise of drilling fluid density and viscosity. And fourth, under the same conditions, the critical return rate for saltation is about 1.28 times that for rolling. It is suggested that the rolling model should be adopted for the normal drilling while the saltation model for the recycle after pump-off sand settling. The research results are of great significance to the optimization of NGH drilling parameters and the reduction of drilling safety risks.

Wen, Y., Amos, R.I.J., Talebi, M., Szucs, R., Dolan, J.W., Pohl, C.A., Haddad, P.R., 2018. Retention index prediction using quantitative structure–retention relationships for improving structure identification in nontargeted metabolomics. Analytical Chemistry 90, 9434-9440.


Structure identification in nontargeted metabolomics based on liquid-chromatography coupled to mass spectrometry (LC-MS) remains a significant challenge. Quantitative structure–retention relationship (QSRR) modeling is a technique capable of accelerating the structure identification of metabolites by predicting their retention, allowing false positives to be eliminated during the interpretation of metabolomics data. In this work, 191 compounds were grouped according to molecular weight and a QSRR study was carried out on the 34 resulting groups to eliminate false positives. Partial least squares (PLS) regression combined with a Genetic algorithm (GA) was applied to construct the linear QSRR models based on a variety of VolSurf+ molecular descriptors. A novel dual-filtering approach, which combines Tanimoto similarity (TS) searching as the primary filter and retention index (RI) similarity clustering as the secondary filter, was utilized to select compounds in training sets to derive the QSRR models yielding R2 of 0.8512 and an average root mean square error in prediction (RMSEP) of 8.45%. With a retention index filter expressed as ±2 standard deviations (SD) of the error, representative compounds were predicted with >91% accuracy, and for 53% of the groups (18/34), at least one false positive compound could be eliminated. The proposed strategy can thus narrow down the number of false positives to be assessed in nontargeted metabolomics.

Wenau, S., Spiess, V., Keil, H., Fei, T., 2018. Localization and characterization of a gas bubble stream at a Congo deep water seep site using a 3D gridding approach on single-beam echosounder data. Marine and Petroleum Geology 97, 612-623.


This study investigates the geometry and temporal variation of a prominent gas bubble stream from a seafloor pockmark in the Lower Congo Basin. We present results of a 3D gridding approach of singlebeam echosounder water column data (Parasound 18 kHz) that increases the lateral resolution and improves the localization of anomalies beyond the inherent depth-dependent footprint size of the sonar system. This allows a detailed reconstruction of gas bubble trajectories through the water column, revealing a stable gas bubble stream for the deepest 1000 m. The bubbles are shifted laterally by ∼200 m in the transition zone between North Atlantic Deep Water and Antarctic Intermediate Water with a reconstructed current velocity of ∼4 cm/s. The direction of lateral shift varies

throughout the ∼15 h survey possibly because of internal waves and small-scale eddies at the water mass boundary. Furthermore, a stacking of SBES water column data acquired during sampling stations showed a periodic variation in seepage intensity with periods of 6 and 8 min, which are likely related to temporally modulated gas supply to the sea floor. Singlebeam echosounder are commonly limited by their small coverage of the survey area during individual passes and their footprint size in detailed imaging of individual seep sites, especially in the deep sea. The presented gridding method for singlebeam echosounder data may facilitate the use of such data in deep water gas bubble stream identification and localization.

White, K.B., Liber, K., 2018. Early chemical and toxicological risk characterization of inorganic constituents in surface water from the Canadian oil sands first large-scale end pit lake. Chemosphere 211, 745-757.


End pit lakes (EPLs) have been proposed as a method for the long-term reclamation of process water and fluid fine tailings (FFT) produced from surface mining within the Canadian oil sands. These waste products contain elevated concentrations of dissolved organics, metals, and salts which reduce surface water quality and are toxic to aquatic organisms. This study measured the concentrations of inorganic constituents in surface water from the industry's first large-scale EPL over the course of a three-year period (2014–2016). The toxicological risk was subsequently assessed to identify constituents of concern that may impair surface water quality necessary for the development of a functional aquatic ecosystem or for release to the surrounding environment. Changes in surface water concentrations over the three-year period were strongly correlated with hydrological processes occurring within the lake: advective-diffusive chemical influx from FFT pore water to the overlying surface water was offset by efflux via continuous manual pumping (freshwater in, process water out). These processes resulted in a net dilution effect of approximately 5–10% per year, however, a significant chemical mass is expected to persist within the underlying FFT. Elevated salinity (as Na+, Cl-, HCO3

–) and concentrations of boron and nickel were predicted to pose very high toxicological risk to aquatic organisms. Despite these risks, the discovery of wild Daphnia pulex in the August 2016 sample suggested that surface water quality was sufficient to support populations of certain salt-tolerant zooplankton and primary producers. However, the time required for development into a robust aquatic ecosystem remains unknown.

Wiesendanger, R., Wacey, D., Tulej, M., Neubeck, A., Ivarsson, M., Grimaudo, V., Moreno-García, P., Cedeño-López, A., Riedo, A., Wurz, P., 2018. Chemical and optical identification of micrometer-sized 1.9 billion-year-old fossils by combining a miniature laser ablation ionization mass spectrometry system with an optical microscope. Astrobiology 18, 1071-1080.


The recognition of biosignatures on planetary bodies requires the analysis of the putative microfossil with a set of complementary analytical techniques. This includes localized elemental and isotopic analysis of both, the putative microfossil and its surrounding host matrix. If the analysis can be performed with spatial resolution at the micrometer level and ppm detection sensitivities, valuable information on the (bio)chemical and physical processes that influenced the sample material can be gained. Our miniaturized laser ablation ionization mass spectrometry (LIMS)-time-of-flight mass spectrometer instrument is a valid candidate for performing the required chemical analysis in situ. However, up until now it was limited by the spatial accuracy of the sampling. In this contribution, we introduce a newly developed microscope system with micrometer accuracy for Ultra High Vacuum

application, which allows a significant increase in the measurement capabilities of our miniature LIMS system. The new enhancement allows identification and efficient and accurate sampling of features of micrometer-sized fossils in a host matrix. The performance of our system is demonstrated by the identification and chemical analysis of signatures of micrometer-sized fossil structures in the 1.9 billion-year-old Gunflint chert.

Wiesmeier, M., Urbanski, L., Hobley, E., Lang, B., von Lützow, M., Marin-Spiotta, E., van Wesemael, B., Rabot, E., Ließ, M., Garcia-Franco, N., Wollschläger, U., Vogel, H.-J., Kögel-Knabner, I., 2019. Soil organic carbon storage as a key function of soils - A review of drivers and indicators at various scales. Geoderma 333, 149-162.


The capacity of soils to store organic carbon represents a key function of soils that is not only decisive for climate regulation but also affects other soil functions. Recent efforts to assess the impact of land management on soil functionality proposed that an indicator- or proxy-based approach is a promising alternative to quantify soil functions compared to time- and cost-intensive measurements, particularly when larger regions are targeted. The objective of this review is to identify measurable biotic or abiotic properties that control soil organic carbon (SOC) storage at different spatial scales and could serve as indicators for an efficient quantification of SOC. These indicators should enable both an estimation of actual SOC storage as well as a prediction of the SOC storage potential, which is an important aspect in land use and management planning. There are many environmental conditions that affect SOC storage at different spatial scales. We provide a thorough overview of factors from micro-scales (particles to pedons) to the global scale and discuss their suitability as indicators for SOC storage: clay mineralogy, specific surface area, metal oxides, Ca and Mg cations, microorganisms, soil fauna, aggregation, texture, soil type, natural vegetation, land use and management, topography, parent material and climate. As a result, we propose a set of indicators that allow for time- and cost-efficient estimates of actual and potential SOC storage from the local to the regional and subcontinental scale. As a key element, the fine mineral fraction was identified to determine SOC stabilization in most soils. The quantification of SOC can be further refined by including climatic proxies, particularly elevation, as well as information on land use, soil management and vegetation characteristics. To enhance its indicative power towards land management effects, further “functional soil characteristics”, particularly soil structural properties and changes in the soil microbial biomass pool should be included in this indicator system. The proposed system offers the potential to efficiently estimate the SOC storage capacity by means of simplified measures, such as soil fractionation procedures or infrared spectroscopic approaches.

Willis, C.E., St. Louis, V.L., Kirk, J.L., St. Pierre, K.A., Dodge, C., 2019. Tailings ponds of the Athabasca Oil Sands Region, Alberta, Canada, are likely not significant sources of total mercury and methylmercury to nearby ground and surface waters. Science of The Total Environment 647, 1604-1610.


Tailings ponds created during industrial bitumen extraction from the Athabasca Oil Sands Region (AOSR), Alberta, Canada, have been shown to contain numerous contaminants, such as polycyclic aromatic compounds and naphthenic acids, and to slowly leak into adjacent ground and surface waters. Despite elevated concentrations of total mercury (THg) in nearby Athabasca River waters downstream of the AOSR developments, to date there are no published studies of THg or methylmercury (MeHg; a potent neurotoxin) in the AOSR tailings ponds. Here we present

concentrations of THg and MeHg, as well as various water chemistry parameters, within four AOSR tailings ponds. Concentrations of SO42−, NH3, Na, and Cl were elevated in tailings ponds relative to nearby freshwaters. Surface water concentrations of THg (filtered: 0.15–0.57 ng/L) and MeHg (unfiltered: <0.02–0.53 ng/L; filtered: <0.02–0.32 ng/L), though, were generally low in the tailings ponds, with the highest concentrations observed in the oldest pond. In the mature fine tailings that settle out in the ponds, concentrations of THg (37.0–197 ng/g) and MeHg (0.10–0.52 ng/g) were also low, with the highest concentrations again in the oldest pond. We calculated that if all the dissolved THg and MeHg potentially leaking annually from the tailings ponds entered the nearby Athabasca River, river THg and MeHg concentrations would increase by only 0.01% and 0.03%, respectively. Overall, these ponds are likely not significant sources of THg or MeHg to nearby ground and surface waters, although due to the potential for Hg methylation to occur in the ponds themselves, other tailings ponds in the AOSR should be monitored to ensure that concentrations of MeHg in them are also low.

Wirth, R., Lakatos, G., Böjti, T., Maróti, G., Bagi, Z., Rákhely, G., Kovács, K.L., 2018. Anaerobic gaseous biofuel production using microalgal biomass – A review. Anaerobe 52, 1-8.


Most photosynthetic organisms store and convert solar energy in an aerobic process and produce biomass for various uses. Utilization of biomass for the production of renewable energy carriers employs anaerobic conditions. This review focuses on microalgal biomass and its use for biological hydrogen and methane production. Microalgae offer several advantages compared to terrestrial plants. Strategies to maintain anaerobic environment for biohydrogen production are summarized. Efficient biogas production via anaerobic digestion is significantly affected by the biomass composition, pretreatment strategies and the parameters of the digestion process. Coupled biohydrogen and biogas production increases the efficiency and sustainability of renewable energy production.



The Permian shales of the Raniganj basin, India, have experienced a dramatic burial history of rapid subsidence (Jurassic-Early Cretaceous) followed by igneous intrusion (Cretaceous) and rapid uplift and erosion (Late Cretaceous-Tertiary). This has left these shales with mixed kerogen macerals with a characteristic thermal signature, ranging from early mature to post mature, which is reflected in the characteristics of their pyrolysis S2 peak. Many of these shales are today at peak thermal maturity but reached that condition more than 100 million years ago. They have significant potential to be exploited as a shale gas resource and their S2 peak characteristics should help to identify sweet spots for such exploitation. Here we analyze single-rate and multi-rate heating ramp Rock-Eval data from a suite of these shales at varying stages of thermal maturity. The S2 peak shapes provide significant insight to the kerogen kinetics involved in their thermal evolution. However, detailed fitting of the peak shapes with kerogen-kinetic mixing models indicate that factors other than static first-order reaction kinetics are also involved in their S2-peak-shape characteristics. Such factors likely include the catalytic effects, influenced by sulfur and charcoal, on some kerogen components, and kerogen pore-size distribution changes during their complex burial and thermal maturation histories. It is likely that the peak-mature shales contain significant, already generated, gas trapped within some of

the kerogen nanopores that may be released during the S2 pyrolysis heating ramp rather than during the S1 heating ramp. This causes the S2 peak to broaden in the mature shales, a characteristic that could be used as an exploration marker for zones best suited to shale gas exploitation.


http://www.cngascn.com:81/ngi_wk/EN/abstract/abstract18595.shtml

The Macro–micro occurrence characteristics of organic matters in shale are significant to determine their genesis, space-time distribution and hydrocarbon generation mechanism. At present, however, the heterogeneity and model of occurrence between different mineral/lithofacies and organic matters are rarely researched. In this paper, the shale of Upper Ordovician Wufeng Fm-Lower Silurian Longmaxi Fm in the Sichuan Basin and its peripheral areas was studied. The genesis and form of inorganic minerals in micrometer–nanometer scale and their contact relationships with organic matters were systematically analyzed by using X-ray diffraction, core observation, scanning electron microscopy (SEM) and so on. Then, on the basis of lithofacies division, the occurrence relationship between lithofacies and organic matters in centimeter–millimeter scale was studied and the genesis, macro–micro distribution and main control factors of organic matters were discussed. And the following research results were obtained. First, the mineral compositions of shale in the study area are mainly quartz and clay minerals and the organic matters are divided into soluble organic matter and insoluble organic matter. Second, there are three types of organic matter occurrence patterns in quartz, clay minerals and carbonate minerals, and four types in pyrite. Third, the shale in the study area can be divided into four typical lithofacies, including organic-rich siliceous shale, high total organic siliceous clayey shale, high total organic limy siliceous shale and organic-lean silty–clayey shale. Fourth, the occurrence of organic matters in the different scales is heterogeneous. The heterogeneity of organic-rich siliceous shale is presented in the laminae formed in the same or similar sedimentary environment. The heterogeneity of organic-lean silty–clayey shale is presented between the laminae formed under different sedimentary environments. Fifth, the main factors controlling the occurrence of organic matters include organic matter types and evolution conditions, genesis and morphology of inorganic components, sedimentary environment, etc. In conclusion, the heterogeneous occurrence of organic matters in different scales influences the coincidence of shale gas "sweet spots" distribution and prediction.

Wu, Y., Jing, X., Gao, C., Huang, Q., Cai, P., 2018. Recent advances in microbial electrochemical system for soil bioremediation. Chemosphere 211, 156-163.


Soil contamination poses a serious threat to ecosystem and human well-being. Compared to conventional physical and chemical treatment, the microbial electrochemical system (MES) offers a sustainable and environment-friendly solution for soil bioremediation. In principle, soil microbe degrades organic substrate and releases electron in anode region. The electron flows through electric circuit to the cathode and finally is accepted by oxygen or oxidized metals. With various inherent advantages, MES has been applied in petroleum hydrocarbon, chlorinated organics and heavy metals bioremediation in soils. This paper aims to review the recent advances of MES in soil bioremediation, including main mechanisms of contaminant removal with MES, configurations of soil MES and current development in bioremediation of soil contaminated by organic and inorganic pollutants. Moreover, challenges and future prospects of soil MES are discussed.

Wu, Y., Zhang, Z., Sun, L., Li, Y., Su, L., Li, X., Xu, H., Tu, Y., 2018. The effect of pressure and hydrocarbon expulsion on hydrocarbon generation during pyrolyzing of continental type-III kerogen source rocks. Journal of Petroleum Science and Engineering 170, 958-966.


Abstrct In order to define the roles of water and lithostatic pressure in petroleum formation of continental type-III kerogen source rocks, semi-closed hydrous pyrolysis experiments were conducted under with 50–1200 bar water pressure and 125–2000 bar lithostatic pressure at 480 °C. Our results will be of great benefit to the exploration of shale gas and deep petroleum in China. Increasing water pressure from 50 to 325 bar did not affect the yields of gaseous hydrocarbons, oil and bitumen, but increasing water pressure leads the more oil and less gaseous hydrocarbons from continental type-III kerogen in the 325–1200 bar water pressure range under semi-closed conditions. The decreasing yields of gaseous hydrocarbons, dryness of gaseous hydrocarbons and primary hydrogen together confirm that increasing water pressure promotes the primary reaction but decreases the cracking rate of oil. The decreasing values of S2, HI and H/C in the pyrolysed samples confirm that high water pressure can increase the efficiency of hydrocarbon generation from continental type-III kerogen, while the maturation of kerogen correspondingly increases as shown by increasing values of VR and Tmax. In the 125–625 bar lithostatic pressure range, oil cracking and primary reaction of type-III kerogen may have contributed to the decreasing effect of hydrocarbon expulsion. The increasing hydrogen and gaseous hydrocarbon yields also confirm that the cracking of oil is enhanced within this pressure range. The decreasing trends of oil and gaseous hydrocarbon yields indicate that hydrocarbon generation rate was reduced by the high lithostatic pressure in the 625–2000 bar pressure range. The increasing values of S2, HI and H/C, and decreasing values of VR and Tmax of pyrolysed samples confirm the retardation effect of highlithostatic pressure on the efficiency of hydrocarbon generation and maturation. In addition, the results also indicate that expelling hydrocarbons strongly promotes further hydrocarbon generation and retards the cracking of oil from continental type-III kerogen in source rocks.

Wunderlich, A., Heipieper, H.J., Elsner, M., Einsiedl, F., 2018. Solvent stress-induced changes in membrane fatty acid composition of denitrifying bacteria reduce the extent of nitrogen stable isotope fractionation during denitrification. Geochimica et Cosmochimica Acta 239, 275-283.


Microcosm experiments with the well-studied denitrifier Thaurera aromatica show a link between a higher maximum membrane concentration (MMC) of the toxic organic solvents 1-octanol and 4-chlorophenol and a higher degree of saturation (DoS) of the fatty acids in the cell membrane. This coincides with less pronounced stable isotope fractionation during denitrification. We suggest that the change in cell membrane fluidity and the cell’s stress response leads to a decrease in nitrate transport across the cell membrane and/or an increase in the relative ratio of respiratory nitrate reduction rate versus efflux of unreacted nitrate. Both models show that the apparent kinetic isotope effect (AKIE) approach unity and thus reduce the extent of the resulting stable isotope enrichment factor ε15N-NO3

− in dissolved nitrate during denitrification, as experimentally and mathematically shown in this study. This may lead to an underestimation of nitrate reduction determined by nitrate stable isotope analysis in aquatic habitats where various types of stresses may affect the physiology of the driving microorganisms.

Xi, Z., Tang, S., Wang, J., 2018. The reservoir characterization and shale gas potential of the Niutitang formation: Case study of the SY well in northwest Hunan Province, South China. Journal of Petroleum Science and Engineering 171, 687-703.


Marine shale is extensive throughout the subsurface, and commercially well-developed as natural gas producers throughout south China, attracting attention in recent years by both politicians and scientists on a variety of issues. Previous research on shale has predominantly focused on the Longmaxi and Niutitang Formations in the Sichuan Basin, but rarely on the periphery in northwestern Hunan Province where the Niutitang Formation has long been known as a potential shale gas reservoir. In this study, hydrocarbon generation potential, reserving performance, and shale gas potential of the Niutitang Formation from northwestern Hunan Province was studied to determine its gas producing potential. Total organic carbon (TOC) analysis, rock-eval pyrolysis, vitrinite reflectance and organic maceral analysis, mercury intrusion, nitrogen adsorption, and methane adsorption were run on a total of 52 samples from the SY well consisting of the Upper and Lower Members of the Niutitang Formation. Analysis of the results showed that the Niutitang shale has high TOC content (2.37% on average), high thermal maturity (3.15% on average), and oil-prone kerogen types, indicating good shale gas potential in the study area. The shale consists of relatively high concentrations of brittle minerals (quartz and feldspar, 69% on average) and low clay content (22% on average), indicating a brittle shale. The shale is a tight formation, with measured porosity averaging 2.66% (free gas potential) and methane adsorption capacity averaged 1.55 cm3/g (adsorbed gas potential). TOC and burial depth control reservoir space of the shale. The Lower Member samples had lower porosity but higher methane adsorption capacity than those from the Upper Member, indicating that a relatively larger amount of gas may occur as adsorbed gas in the Lower Member. It is suggested that the Lower Member of the Niutitang Formation is the ideal location for exploration and development of shale gas due to consistently thick organic-rich layers, high TOC content, high brittleness index, and stronger adsorption capacity.

Xie, J., 2018. Rapid shale gas development accelerated by the progress in key technologies: A case study of the Changning–Weiyuan National Shale Gas Demonstration Zone. Natural Gas Industry B 5, 283-292.


Shale gas resources in the Lower Silurian Longmaxi, southern Sichuan Basin, are huge, where, the geological setting, unlike that in North America, is quite complicated and ground surface infrastructure is poor. Therefore, adaptable key technologies will be essential to achieve commercial exploitation of shale gas there. In the case study of the Changning–Weiyuan National Shale Gas Demonstration Zone, six series of key techniques were summarized in comprehensive geological evaluation, development optimization, fast and superior drilling of horizontal wells, horizontal-well volumetric fracturing, cluster-well and factory-like operation in well blocks, and highly-efficient and clean exploitation. The above techniques were applied in this field after three rounds of adjustment and optimization, the resulted production rates of shale gas wells were getting higher and higher and the single-well estimated ultimate recovery (EUR) was also rising. Compared with that in the first round, the average EUR of wells in the third round was increased by 128%. In conclusion, the application practices prove that the above series of key techniques with adaptation and flexibility provide a robust technical support for the rapid output of shale gas production in South Sichuan Basin.

Xie, S.-M., Fu, N., Li, L., Yuan, B.-Y., Zhang, J.-H., Li, Y.-X., Yuan, L.-M., 2018. Homochiral metal–organic cage for gas chromatographic separations. Analytical Chemistry 90, 9182-9188.


Metal–organic cages (MOCs) as a new type of porous material with well-defined cavities were extensively pursued because of their relative ease of synthesis and their potential applications in host–guest chemistry, molecular recognition, separation, catalysis, gas storage, and drug delivery. Here, we first reported that a homochiral MOC [Zn3L2] is explored to fabricate [Zn3L2] coated capillary column for high-resolution gas chromatographic separation of a wide range of analytes, including n-alkanes, polycyclic aromatic hydrocarbons, and positional isomers, especially for racemates. Various kinds of racemates such as alcohols, diols, epoxides, ethers, halohydrocarbons, and esters were separated with good enantioselectivity and reproducibility on the [Zn3L2] coated capillary column. The fabricated [Zn3L2] coated capillary column exhibited significant chiral recognition complementary to that of a commercial β-DEX 120 column and our recently reported homochiral porous organic cage CC3-R coated column. The results show that the homochiral MOCs will be very attractive as a new type of chiral selector in separation science.

Xiong, W., Lo, J., Chou, K.J., Wu, C., Magnusson, L., Dong, T., Maness, P., 2018. Isotope-assisted metabolite analysis sheds light on central carbon metabolism of a model cellulolytic bacterium Clostridium thermocellum. Frontiers in Microbiology 9, 1947. doi: 10.3389/fmicb.2018.01947.


Cellulolytic bacteria have the potential to perform lignocellulose hydrolysis and fermentation simultaneously. The metabolic pathways of these bacteria, therefore, require more comprehensive and quantitative understanding. Using isotope tracer, gas chromatography-mass spectrometry, and metabolic flux modeling, we decipher the metabolic network of Clostridium thermocellum, a model cellulolytic bacterium which represents as an attractive platform for conversion of lignocellulose to dedicated products. We uncover that the Embden–Meyerhof–Parnas (EMP) pathway is the predominant glycolytic route whereas the Entner–Doudoroff (ED) pathway and oxidative pentose phosphate pathway are inactive. We also observe that C. thermocellum's TCA cycle is initiated by both Si- and Re-citrate synthase, and it is disconnected between 2-oxoglutarate and oxaloacetate in the oxidative direction; C. thermocellum uses a citramalate shunt to synthesize isoleucine; and both the one-carbon pathway and the malate shunt are highly active in this bacterium. To gain a quantitative understanding, we further formulate a fluxome map to quantify the metabolic fluxes through central metabolic pathways. This work represents the first global in vivo investigation of the principal carbon metabolism of C. thermocellum. Our results elucidate the unique structure of metabolic network in this cellulolytic bacterium and demonstrate the capability of isotope-assisted metabolite studies in understanding microbial metabolism of industrial interests.

Xu, J., Zhai, C., Qin, L., Liu, S., 2018. Pulse hydraulic fracturing technology and its application in coalbed methane extraction. International Journal of Oil, Gas and Coal Technology 19, 115-133.

http://dx.doi.org/10.1504/IJOGCT.2018.10014796

The sealing and operating procedures of pulse hydraulic fracturing (PHF) were systematically introduced to increase the methane reservoir permeability. The results of a pilot application conducted at Sv719 working face in Daxing coal mine, China, shown that both the sealing and cracking were successfully operated. The injection time and water quantity were positively correlated with the

fracturing initiation pressure. The fracturing mechanism of PHF was theoretically analysed, and the relationship between fatigue-loaded coal strength and injecting frequency was studied. A criterion for determining the fracture pressure was established. Compared to conventional hydraulic fracturing and deep-hole blasting, PHF technology is superior in gas-extraction performance, with a relatively high extraction concentration and less gas attenuation. Moreover, the content and pressure of residual gas in the fractured coal seams were reduced below the regulatory limits, with decrease of 46.15-83.67% and 61.61%, respectively.

Xu, Y., Sommerdijk, N.A.J.M., 2018. Aragonite formation in confinements: A step toward understanding polymorph control. Proceedings of the National Academy of Sciences 115, 8469-8471.


Calcium carbonate (CaCO3) is one of the most common minerals on Earth; it not only forms rocks like limestone or marble but is also a main component of biominerals such as pearls, the nacre of seashells, and sea-urchin skeletons. Despite many years of research, the polymorphism of CaCO3 is still far from being understood. CaCO3 has three anhydrous crystalline forms: calcite, aragonite, and vaterite, with a decreasing thermodynamic stability under aqueous ambient conditions (calcite > aragonite > vaterite). While vaterite is rare in nature, calcite and aragonite are both frequently found in rocks or biominerals. A well-known example is the aragonite structure of nacre, where the organization of the crystals leads to extraordinary mechanical performance. However, in synthetic systems, crystallization experiments only generate a small fraction of aragonite compared with calcite at ambient conditions and in the absence of additives. So, how is the formation of aragonite facilitated in nature, especially in biominerals? In PNAS, Zeng et al. shed light on this matter by showing that aragonite formation is dramatically promoted within confinements.

In recent decades, great efforts have been spent toward understanding the strategies exploited by organisms to regulate aragonite formation, and several key factors have been identified. Up to now, the effect of Mg2+ additive is the most well established. Mg2+ is abundant in seawater and is expected to be present during the formation of many marine biominerals. At high Mg2+:Ca2+ ratios, aragonite forms as the …

Xue, P.-P., Carrillo, Y., Pino, V., Minasny, B., McBratney, A.B., 2018. Soil properties drive microbial community structure in a large scale transect in South Eastern Australia. Scientific Reports 8, Article 11725.

https://doi.org/10.1038/s41598-018-30005-8

Soil microbial communities directly affect soil functionality through their roles in the cycling of soil nutrients and carbon storage. Microbial communities vary substantially in space and time, between soil types and under different land management. The mechanisms that control the spatial distributions of soil microbes are largely unknown as we have not been able to adequately upscale a detailed analysis of the microbiome in a few grams of soil to that of a catchment, region or continent. Here we reveal that soil microbes along a 1000 km transect have unique spatial structures that are governed mainly by soil properties. The soil microbial community assessed using Phospholipid Fatty Acids showed a strong gradient along the latitude gradient across New South Wales, Australia. We found that soil properties contributed the most to the microbial distribution, while other environmental factors (e.g., temperature, elevation) showed lesser impact. Agricultural activities reduced the variation of the microbial communities, however, its influence was local and much less than the overall influence of soil properties. The ability to predict the soil and environmental factors that

control microbial distribution will allow us to predict how future soil and environmental change will affect the spatial distribution of microbes.


https://doi.org/10.1080/10916466.2018.1471502

Features of the content and distribution of vanadium and vanadyl porphyrins in the fractions of resins, which were obtained by separation using column chromatography on silica, have been studied on heavy sulfurous oils of various deposits of the Volga?Ural basin (Russia). The difference of the vanadium and vanadyl porphyrin contents in the fractions of oils of various production complexes has been shown. Features of structural?group composition and predominant types of vanadyl porphyrins in the fractions of resins have been determined.

Yalçin Erik, N., 2018. Biological marker indicators of paleo-depositional environment for the Eocene formations around Zara-Bolucan region (central anatolia, Turkey). Advances in Geo-Energy Research 2, 237-244.


Biological marker (biomarker) characteristics and paleo-depositional conditions of Eocene sediments around Zara-Bolucan northeast of Sivas Basin have been determined by means of detail organic geochemical studies such as gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. In the investigated area, northeast section of the Sivas Basin, the Eocene Bozbel and Kozluca Formations consist of a organic matter rich sedimentary rocks deposited within trangressive-regressive cycles. During the evaluation of paleoenvironment characteristics with biomarker data, data related to n-alkanes, isoprenoids, terpenoids and steroids were used. Especially, the marine environment features indicated by C23 tricyclic/C30 hopane, the C26 /C25 tricyclic terpanes, homohopane/C30 hopane and diasterane/regular sterane data. The ratios of Pr/Ph, Pr/n-C17 and Ph/n-C18 indicate that there is marine organic matter predominantly precipitated under reducing environmental conditions. In the studied samples, the algal-bacterial organic matter contribution was interpreted to be due to the superiority of the C23 tricyclic terpene to C24 , as well as larger than the C24 tricyclic terpane. However, the gammacerane index suggests that there is initially a low salinity environment. The significant terrestrial organic matter contribution is indicated by the isoprenoid and biomarker ratios, dominance of higher n-alkanes such as n-C29 , n-C31 , CPI, TAR values, n-C19 /n-C31, relative abundance of C27-C28-C29 regular steranes. Suboxic to anoxic palo-depositional conditions are confired by the isoprenoid and n-alkane ratios and T m /T s , C 29 T s /C 29 hopane ratios.

Yan, F., Sillanpää, M., Kang, S., Aho, K.S., Qu, B., Wei, D., Li, X., Li, C., Raymond, P.A., 2018. Lakes on the Tibetan Plateau as conduits of greenhouse gases to the atmosphere. Journal of Geophysical Research: Biogeosciences 123, 2091-2103.

https://doi.org/10.1029/2017JG004379

Lakes play an important role in the global carbon cycle, and littoral zones of lakes are potential hotspots of greenhouse gas production. In this study, we measured the partial pressures of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in the littoral zones of 17 lakes on the Tibetan

Plateau. The littoral zones of lakes on the Tibetan Plateau were supersaturated and acted as sources of CO2, CH4, and N2O to the atmosphere. The average partial pressures of CO2, CH4, and N2O in the surface lake water were 664.8 ± 182.5, 139.8 ± 335.6, and 0.3 ± 0.1 μatm, respectively. The average diffusive fluxes (and uncentainty intervals) of these three gases were 73.7 (0.9–295.3) mmol · m−2 · day−1, 5.2 (0.0008–45.9) mmol · m−2 · day−1, and 6.5 (0.07–20.9) μmol · m−2 · day−1, respectively. The diffusive fluxes of CO2 in lakes were significantly correlated with dissolved organic carbon, dissolved organic nitrogen, salinity, and water temperature. The diffusive fluxes of N2O were significantly correlated with lake water depth. However, no relationships were found between environmental factors and the CH4 diffusive flux at the scale of this study. CO2 exchange with the atmosphere from saline lakes was found to be higher than from freshwater lakes with equivalent CO2 concentrations by a factor of 2.5 due to chemical enhancement of the gas transfer velocity. Therefore, further study with enhanced spatiotemporal resolution and breadth is needed to better understand the important role played by lakes on the Tibetan Plateau in both regional and global carbon cycles.

Yao, H., Hong, W.-L., Panieri, G., Sauer, S., Torres, M.E., Lehmann, M.F., Gründger, F., Niemann, H., 2018. Fracture-controlled fluid transport supports microbial methane oxidizing communities at the Vestnesa Ridge Biogeosciences Discussions 2018, 1-17.

https://doi.org/10.5194/bg-2018-321

We report on a rare observation of a mini-fracture in near-surface sediments (30cm below the seafloor) visualized using rotational scanning X-ray of a core recovered from the Lomvi pockmark, Vestnesa Ridge west of Svalbard (1200m water depth). Porewater geochemistry and lipid biomarker signatures revealed clear differences in the geochemical and biogeochemical regimes of this core compared with two additional ones recovered from pockmarks sites at Vestnesa Ridge, which we attribute to differential methane transport mechanisms. In the sediments core featuring the shallow mini-fracture at pockmark Lomvi, we observed high concentrations of both methane and sulfate throughout the core in tandem with moderately elevated values for total alkalinity, 13C-depleted dissolved inorganic carbon (DIC), and 13C-depleted lipid biomarkers (diagnostic for the slow-growing microbial communities mediating the anaerobic oxidation of methane with sulfate – AOM). In another core recovered from the same pockmark about 80m away from the fractured core, we observed complete sulfate depletion in the top centimeters of the sediment and much more pronounced signatures of AOM than in the fractured core. Our data indicate a gas advection-dominated transport mode in both cores facilitating methane migration into sulfate-rich surface sediments. However, the more moderate expression of AOM signals suggest a rather recent onset of gas migration at the site of the fractured core, while the geochemical evidence for a well-established AOM community at the second coring site at the Lomvi pockmark suggest that gas migration has been going on for a longer period of time. A third core recovered from Lunde pockmark was dominated by diffusive transport with only weak geochemical and biogeochemical evidence for AOM. Our study highlights that advective fluid and gas transport supported by mini-fractures can be important in modulating methane dynamics in surface sediments.

Yao, W., Paytan, A., Wortmann, U.G., 2018. Large-scale ocean deoxygenation during the Paleocene-Eocene Thermal Maximum. Science 361, 804-806.


Abstract: The consequences of global warming for fisheries are not well understood, but the geological record demonstrates that carbon cycle perturbations are frequently associated with ocean deoxygenation. Of particular interest is the Paleocene-Eocene Thermal Maximum (PETM), where the

carbon dioxide input into the atmosphere was similar to the IPCC RCP8.5 emission scenario. Here we present sulfur-isotope data that record a positive 1 per mil excursion during the PETM. Modeling suggests that large parts of the ocean must have become sulfidic. The toxicity of hydrogen sulfide will render two of the largest and least explored ecosystems on Earth, the mesopelagic and bathypelagic zones, uninhabitable by multicellular organisms. This will affect many marine species whose ecozones stretch into the deep ocean.

Editor's summary: Fishin' gone? Because gas solubility decreases as temperatures increase, global warming is likely to cause oxygen loss from the oceans. This could have a detrimental impact on fish populations, the fishing industry, and global food availability. Have such impacts occurred before? Yao et al. report sulfur isotopic data from the Paleocene-Eocene Thermal Maximum, an interval around 55 million years ago when atmospheric carbon dioxide concentrations and global temperatures were also high. They found widespread anoxia and resulting high concentrations of hydrogen sulfide, which is toxic to marine organisms. Similar effects could have severe negative effects on ocean ecosystems.

Yihdego, Y., Salem, H.S., Kafui, B.G., Veljkovic, Z., 2018. Economic geology value of oil shale deposits: Ethiopia (Tigray) and Jordan. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 40, 2079-2096.

https://doi.org/10.1080/15567036.2018.1488015

Oil shale is an organic-rich, fine-grained sedimentary rock, containing kerogen, from which liquid hydrocarbons (called shale oil) can be produced. The oil shale deposits in the Tigray region are found in the northern parts of Ethiopia, Eastern Africa. They are of Upper Paleozoic in age, existing as remnants of the Cretaceous erosion period, underlain by tillites and overlain by sandstones. They were formed during the glacial retreat followed by marine deposition of shales in a basin created by the enormous load of the glaciers. The Ethiopian-Tigray oil shale deposits cover an area extending over approximately 30 km2, with an average mineable bed-thickness of 55 m, showing on the upper part inter-beds and laminations of shaley limestones. The oil shale resources in this region are estimated to be approximately 4 billion tonnes. The exploitation of the Ethiopian-Tigray oil shale deposits is an excellent alternative to fulfill the fuel and other petroleum products? demand of Ethiopia. This study sheds light on the oil shale resources in the Ethiopian region of Tigray, as they are fairly investigated, regarding their geological characterization, and future strategies for their exploration and exploitation potential. In addition, the oil shale deposits in Jordan are also moderately investigated, as Jordan is considered a promising country for shale oil, taking into account that Jordan has no other hydrocarbon resources (such as crude oil and natural gas), unlike many other countries in the MENA (Middle East and North Africa) region, as MENA sets on ?seas? of oil and natural gas. Furthermore, oil shale in the USA is also briefly investigated, as the USA is being the world?s largest country of oil shale resources and reserves. Also, some other issues related to the oil shale industry are investigated, such as economics, extraction technologies of shale oil, and the environmental impacts.

Yu, C., Tran, H., Sakhaee-Pour, A., 2018. Pore size of shale based on acyclic pore model. Transport in Porous Media 124, 345-368.

https://doi.org/10.1007/s11242-018-1068-4

The transport properties inside a nanosize conduit, such as viscosity and density, deviate from those reported at unconfined conditions with an identical pressure and temperature. The deviation from the

nominal value is well studied for the simple topology in nanofluidics. A straight circular tube is an example of a simple topology. The pore space inside the matrix of a shale formation is also a nanofluidic system, because its characteristic size is smaller than or equal to 100 nm, but it includes a complex structure. With this in mind, we determine the pore-throat and pore-body size distributions of different shales whose data are available in the literature. The main objective is to quantitatively distinguish the two sizes, whose importance is overlooked in the study of shale formations. The pore-throat size distribution is determined from mercury injection capillary pressure measurements, and the pore-body size distribution is derived from nitrogen adsorption–desorption. The acyclic pore model, which is physically representative of the pore space at the core scale, allows us to interpret the petrophysical measurements. Our study of different shales shows that the average pore-body size is usually larger than 20 nm; thus, there is no need to account for the pore proximity (confinement). The pore-throat size distributions of different shales usually fall below 20 nm, which entails the modification of a transport property that is relevant to the formation resistance against the flow.

Yu, K., Cao, Y., Qiu, L., Sun, P., 2018. The hydrocarbon generation potential and migration in an alkaline evaporite basin: The Early Permian Fengcheng Formation in the Junggar Basin, northwestern China. Marine and Petroleum Geology 98, 12-32.


The Permian Fengcheng Formation in the Mahu Sag in the Junggar Basin represents deposition in a rare alkaline saline lake, with hydrologically closed conditions, alkaline saline brines, and intense volcanic activity. The Fengcheng Formation contains large volumes of high-quality source rocks, which form not only in the depocenter but also in the wide, shallow lake margins. The source rocks analyzed in this study are different from those in most other ancient lakes in the following aspects: genesis and occurrence of organic matter, kerogen type, lithological composition, and hydrocarbon migration pathway. This study showed that the Fengcheng Formation has high hydrocarbon generation potential and that combinations of multiple paths enhanced the hydrocarbon expulsion and migration. Benthic microbial mats and algae that bloomed in the alkaline saline lake represent the dominant types of organic matter. Due to their specific composition, the evaporites may have catalyzed hydrocarbon generation via organic-inorganic interactions, while intergranular seams in bedded/laminated evaporites provided paths for hydrocarbon migration. Stylolites, with high contents of brittle minerals and low clay content, also allowed favorable paths for hydrocarbon expulsion and migration. Combining hydrocarbon expulsion fractures in the organic-rich laminae, fractures and microfractures caused by compressive tectonic stress, pathway networks formed that enhanced the efficiencies of both hydrocarbon expulsion and migration.

Yu, X., Zhang, W., Liu, X., Lei, J., Lin, Z., Yao, Z., Yao, X., Jin, X., Yang, H., Huang, H., 2018. The distribution of and biodegradation impact on spilled oil in sediments from Dalian Bay, NE China. Marine Pollution Bulletin 135, 1007-1015.


Three cores collected in the area of 16th July 2010 oil spill by box crab in May 2013 and July 2014 at the Dalian Bay have been geochemically characterized to investigate the fate of chemical components in sediments. The total organic carbon, extractable organic matter contents and biomarker compositions have been applied for the differentiation of alien organic matters from in situ ones and evaluation of the biodegradation impact. Multivariate statistical analysis suggests four groups of sediments. Except a few samples at deepest part of BQ050, majority samples have certain affinity with the spilled oil. The most contaminated sediments occur at site BQ050 and the spilled oil has

migrated to 8–12 cm depth. The degree of contamination can be ranked by the similarity of molecular compositions with spilled oil. Variable biomarker components in sediment extracts were also altered by ongoing biodegradation.



Using six representative feedstocks as carbonaceous precursors, various mesophase pitches and their derived cokes were obtained by a heat-soaking method at a temperature range of 400–450 °C and a pyrolysis treatment at 900 °C, respectively. The optical texture and microstructure of the different mesophase pitches and their derived cokes were characterized by polarized-light microscope, scanning electron microscope, and X-ray diffraction. The results show that the formation and development abilities of liquid crystalline mesophase are obviously different for the various feedstocks. C9 aromatic hydrocarbons and petroleum-derived paving pitch possess relatively high thermo-chemical reactivity due to the existence of low molecular substances and aliphatic groups, leading to form liquid crystalline mesophase easier and faster than those of naphthalene synthetic pitch and coal tar-based impregnating pitch under a similar condition, which however is undesirable to develop a bulk mesophase. Anthracene possesses a characteristic of forming a homogeneous bulk mesophase with a streamline texture under a suitable condition. The liquid crystalline transformation behavior of C5–C9 aromatic hydrocarbons is unexpectedly similar to that of naphthalene synthetic pitch and markedly different from that of C9 aromatic hydrocarbons. Carbonaceous precursors have a significant effect on the anisotropic content and the optical texture of the mesophase pitch products, which leads to the microstructure variety of the resultant cokes. Fine-grained and coarse-grained mosaic textures are, respectively, present in the cokes derived from C9 aromatic hydrocarbons and petroleum-derived paving pitch. The cokes derived both from coal tar-based impregnating pitch and from C5–C9 aromatic hydrocarbons possess a supra mosaic texture mingled with a local flow-induced orientation domain. A well-oriented lamellar texture is clearly found in the cokes derived from anthracene and naphthalene synthetic pitch.



Solid-phase humic substances (also termed humins, HMs) are the largest fraction of humic substances (HSs) in soils and sediments, which are recently shown to be capable of mediating electron transfer in many key biogeochemical processes. However, the redox properties of HMs remains poorly investigated, likely due to their structural complexity and the lack of efficient methodology. Herein, an electrochemical in situ FITR spectroscopic (EC-FTIRS) technique coupled with two-dimensional correlation spectroscopy (2D-COS) was employed for the first time to study the redox process of complex HMs at a molecular level. In situ FTIR identified that the IR bands of quinone and phenolic moieties in the HMs were potential dependent, suggesting that they were the main redox sites in response to the redox transformation of the HMs. Meanwhile, In situ FTIR characterizations showed that the significant variations in IR bands positioned at ~1500 and ~1470 cm−1 in response to the applied potentials, providing evidence for the presence of quinone radical and dianion intermediates during the redox process. The 2D-COS analysis was used to further explore variations in infrared

intensities as a function of the potentials applied to reduce or oxidize the HMs, which indicated the occurrence of the typical redox reactions of quinone in the HMs. These results improve our understanding on the redox mechanism of HMs at the molecular level and have significant implication for in-depth understanding of biogeochemical processes.

Zaccone, C., Beneduce, L., Lotti, C., Martino, G., Plaza, C., 2018. DNA occurrence in organic matter fractions isolated from amended, agricultural soils. Applied Soil Ecology 130, 134-142.


The persistence of soil organic matter (SOM) constituents as a function of their recalcitrance has been recently questioned, with several papers showing the influence of the combined action of physical protection and chemical stabilization mechanisms as the main factors affecting SOM mean residence time. Using a physical fractionation method, SOM located between aggregates (FR), occluded within macro- (MA) and micro-aggregates (MI), and associated with the mineral fractions (MIN) were isolated from an agricultural soil differently amended (using compost, sewage sludge and biochar), and the occurrence of (total, bacterial and plant) DNA in these SOM pools was investigated. Following physical fractionation, total DNA (tDNA) was recovered from all SOM pools and from all treatments. Independently from the amendment, most tDNA accumulates in the FR fraction (30–70%), followed by the MIN pool (25–55%). The positive correlation between tDNA contents and C/N ratios (both tending to decrease following the order FR, MA and MI) observed for the light SOM fractions, together with the opposite pattern characterizing the heavy, MIN fraction (characterized by relatively high tDNA contents and low C/N ratios), suggests a different origin of the latter SOM pool, i.e., new molecules resulting from microbial transformations rather than highly degraded litter inputs. Therefore, tDNA may represent a promising proxy of organic matter dynamics in mineral soils. Finally, the MI fraction shows the highest number of microbial taxa and diversity, and seems to constitute a separate microbial niche in which different bacterial communities carry out their activity.

Zaeri, M.R., Hashemi, R., Shahverdi, H., Sadeghi, M., 2018. Enhanced oil recovery from carbonate reservoirs by spontaneous imbibition of low salinity water. Petroleum Science 15, 564-576.

https://doi.org/10.1007/s12182-018-0234-1

An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity, permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.

Zakharov, Y.D., Horacek, M., Popov, A.M., Bondarenko, L.G., 2018. Nitrogen and carbon isotope data of Olenekian to Anisian deposits from Kamenushka/South Primorye, far-eastern Russia and their palaeoenvironmental significance. Journal of Earth Science 29, 837-853.

https://doi.org/10.1007/s12583-018-0792-6

The Kamenushka Formation, exposed in the northern part of South Primorye (Kamenushka-1 and Kamenushka-2 sections), is one of the few localities in the world with richly fossiliferous Lower–Upper Olenekian sedimentary successions. Lower to Middle Triassic ammonoid-, brachiopod- and conodont-bearing silty-clayey deposits of the Kamenushka-1 and Kamenushka-2 sections have been isotope-geochemically investigated in detail. As a result, these sections, together with the previously investigated Abrek Section, exposed in the southern part of South Primorye, provide almost complete 15Norg- and 13Corg- records for the Lower Triassic of this region. Nine N-isotope intervals and the five negative C-isotope excursions, reflecting, apparently, unstable climatic and hydrological conditions, have been distinguished in the Lower Triassic of South Primorye. On the basis of the new C-isotope data the Mesohedenstroemia bosphorensis Zone (upper part), Shimanskyites shimanskyi and Neocolumbites insignis zones of South Primorye are correlated now with the Lower Smithian part of the Yinkeng Formation, the Upper Smithian part of the Helongshan Formation and the Middle Spathian part of the Nanlinghu Formation in South China, respectively, as has been observed in the Abrek, Kamenushka-2, West Pingdingshan and Majiashan sections.



In the present study, hierarchical cluster analysis was used to select 150 S500 diesel fuel samples from an initial set of 1320 samples assayed through official standards according to ANP Brazilian Regulation No. 50/2013. Four physicochemical properties were analyzed, namely, relative density, distillation temperatures (T10%, T50%, and T85%), flash point, and cetane number. Selected samples were also analyzed by gas chromatography with flame ionization detection (GC-FID), a very common technique used for fuel quality control due to its convenience, accuracy, simplicity, and possible association of the chromatographic profiles with multivariate analyses. PLS regression models were obtained aiming at predicting the four physicochemical properties of the diesel fuel samples. From a maximum chromatographic analysis time of 108 min, regression models with unbiased predictions and good prediction capability for all properties were obtained, with average relative errors lower than 6%.

Zark, M., Dittmar, T., 2018. Universal molecular structures in natural dissolved organic matter. Nature Communications 9, Article 3178.

https://doi.org/10.1038/s41467-018-05665-9

Natural dissolved organic matter (DOM) comprises a broad range of dissolved organic molecules in aquatic systems and is among the most complex molecular mixtures known. Here we show, by comparing detailed structural fingerprints of individual molecular formulae in DOM from a set of four marine and one freshwater environments, that a major component of DOM is molecularly indistinguishable in these diverse samples. Molecular conformity was not only apparent by the co-occurrence of thousands of identical molecular formulae, but also by identical structural features of

those isomers that collectively represent a molecular formula. The presence of a large pool of compounds with identical structural features in DOM is likely the result of a cascade of degradation processes or common synthetic pathways that ultimately lead to the formation of a universal background, regardless of origin and history of the organic material. This novel insight impacts our understanding of long-term turnover of DOM as the underlying mechanisms are possibly universal.

Zhang, S., Planavsky, N.J., Krause, A.J., Bolton, E.W., Mills, B.J.W., 2018. Model based Paleozoic atmospheric oxygen estimates: a revisit to GEOCARBSULF. American Journal of Science 318, 557-589.


Geological redox proxies increasingly point towards low atmospheric oxygen concentrations during the early Paleozoic Era, with a subsequent protracted rise towards present-day levels. However, these proxies currently only provide qualitative estimates of atmospheric O2 levels. Global biogeochemical models, in contrast, are commonly employed to generate quantitative estimates for atmospheric O2 levels through Earth's history. Estimates for Paleozoic pO2 generated by GEOCARBSULF, one of the most widely implemented carbon and sulfur cycle models, have historically suggested high atmospheric O2 levels throughout the Paleozoic, in direct contradiction to competing models. In this study, we evaluate whether GEOCARBSULF can predict relatively low Paleozoic O2 levels. We first update GEOCARBSULF by adopting the recent compilation of the δ13C value of marine buried carbonate and replacing the old formulation of the sulfur isotope fractionation factor with empirical sulfur isotope records. Following this we construct various O2 evolution scenarios (with low O2 levels in the early Paleozoic) and examine whether GEOCARBSULF can reproduce these scenarios by varying the weathering/degassing fluxes of carbon and sulfur, or carbonate δ13C. We show that GEOCARBSULF can, in fact, maintain low-O2 (even 1–5% atm) levels through the early Paleozoic by only varying the carbonate δ13C within 2 standard deviation (SD) bounds permitted by the geological record. In addition, it can generate a middle–late Paleozoic rise in O2 concentration, coincident with the diversification of land plants. However, we also argue that tracking atmospheric O2 levels with GEOCARBSULF is highly dependent on carbonate carbon isotope evolution, and more accurate predictions will come from an improved C isotope record.

Zhang, S., Riva, J.F., 2018. The stratigraphic position and the age of the Ordovician organic-rich intervals in the northern Hudson Bay, Hudson Strait, and Foxe basins—evidence from graptolites. Canadian Journal of Earth Sciences 55, 897-904.

https://doi.org/10.1139/cjes-2017-0266

Graptolites recovered from the organic-rich intervals, previously named the Boas River Formation in the Upper Ordovician succession on Southampton, Akpatok, and southern Baffin islands provide a reliable age assessment for the Upper Ordovician petroleum source rocks in the northern Hudson Bay, Hudson Strait, and Foxe basins. They are characterised by Anticostia lata and Anticostia hudsoni in the lower Red Head Rapids Formation on Southampton Island; Anticostia decipiens and Rectograptus socialis in the lower Foster Bay Formation on Akpatok Island; and Diplacanthograptus spiniferus and Amplexograptus praetypicalis in the lower Amadjuak Formation on southern Baffin Island. These data suggest that the organic-rich intervals in the northern Hudson Bay and Hudson Strait basins can be correlated to the Dicellograptus anceps and Paraorthograptus pacificus zones of the upper Katian, and the horizon in the Foxe Basin to the Diplacanthograptus spiniferus Zone of the lower Katian. The Boas River Formation is not deemed appropriate to use as it occurs as an organic-

rich interbed in different stratigraphic units in different basins; therefore, it is suggested to abandon it as a stratigraphic term.

Zhang, X.-C., Zang, Q., Zhao, H., Ma, X., Pan, X., Feng, J., Zhang, S., Zhang, R., Abliz, Z., Zhang, X., 2018. Combination of droplet extraction and pico-ESI-MS allows the identification of metabolites from single cancer cells. Analytical Chemistry 90, 9897-9903.


We have combined droplet extraction and a pulsed direct current electrospray ionization mass spectrometry method (Pico-ESI-MS) to obtain information-rich metabolite profiling from single cells. We studied normal human astrocyte cells and glioblastoma cancer cells. Over 600 tandem mass spectra (MS2) of metabolites from a single cell were recorded, allowing the successful identification of more than 300 phospholipids. We found the ratios of unsaturated phosphatidylcholines (PCs) to saturated PCs were significantly higher in glioblastoma cells compared to normal cells. In addition, both isomeric PC (17:1) and (phosphatidylethanolamine) PE (20:1) were found in glioblastoma cells, whereas only PC (17:1) was observed in astrocyte cells. Our method paves the way to characterize the chemical contents of single cells, providing rich metabolome information. We suggest that this technique is general and can be applied to other life science studies such as differentiation and drug resistance of individual cells.

Zhang, Y., Douglas, G.B., Kaksonen, A.H., Cui, L., Ye, Z., 2019. Microbial reduction of nitrate in the presence of zero-valent iron. Science of The Total Environment 646, 1195-1203.


Microbial reduction of nitrate in the presence of zero-valent iron (ZVI) was evaluated in anoxic shake flasks to assess the feasibility of ZVI-facilitated biological nitrate removal. Nitrate was completely reduced within 3 days in the presence of both ZVI and microorganisms (ZVI-M). In contrast, only 75% of the nitrate was reduced in the presence of ZVI but without microbial inoculum. Nitrate removal was affected by ZVI-M flasks initial pH, nitrate concentration and ZVI dosage. Nitrate removal in the inoculated ZVI flasks system could be divided into two phases: adaptation phase and log phase which could be described by first-order kinetic equations. The analysis of bacterial communities in the inoculated flasks in the absence and presence of ZVI, indicated that the addition of ZVI increased the relative abundance of Methylotenera spp., Alcaligenes eutrophus, Pseudomonas spp. which might play an important role in nitrogen removal. The presence of ZVI could enhance biological denitrification through four mechanisms: the biological reduction of nitrate with 1) electrons derived directly from ZVI; 2) with hydrogen released from ZVI; 3) with Fe2+ released from ZVI; and 4) with acetate generated by homoacetogens which utilize H2 released from ZVI.

Zhang, Y.G., Liu, X., 2018. Export depth of the TEX86 signal. Paleoceanography and Paleoclimatology 33, 666-671.

https://doi.org/10.1029/2018PA003337

Abstract: TEX86 is widely used for evaluating ancient ocean temperatures. However, the debate on the export depth of the TEX86 signal in the water column has not been settled. Consequently, TEX86 has been interpreted as/calibrated to surface, shallow subsurface, or deep subsurface temperatures. Here we examine the published core top TEX86 data between 30°N and 30°S where the ocean temperatures at the surface show a clear latitudinal gradient, but not at the deep subsurface. The meridional

distribution of the TEX86 data exhibits an inverted U shape with the peak near the equator, which closely resembles the surface and shallow subsurface ocean temperature profiles. And the strongest correlation was identified between TEX86 and sea surface temperatures. These results suggest that on the global scale, sedimentary TEX86 is a proxy for temperatures of the epipelagic ocean less than 200 m deep.

Plain Language Summary: Archaea is one of the three domains of life. Their membrane lipids, called GDGTs (glycerol dialkyl glycerol tetraethers), are found in modern marine sediments as well as those that are hundreds of millions of years old. Seawater temperature changes affect the archaeal biosynthesis of GDGTs. As a consequence, an ocean temperature proxy TEX86 has been developed based on the distribution of GDGTs. TEX86 is widely applied to study past ocean temperature changes. However, whether TEX86 is reflecting surface‐shallow subsurface or deep subsurface temperatures is being debated. By comparing surface sediment TEX86 data with modern ocean temperature distributions, we conclude that globally, TEX86 is a signal originated from less than 200 m deep in the water column.

Zhang, Z., Wei, Z., Wang, J.J., Xiao, R., Meng, Y., Wu, H., Lyu, X., 2018. Ants alter molecular characteristics of soil organic carbon determined by pyrolysis-chromatography/mass spectrometry. Applied Soil Ecology 130, 91-97.


Colonization by ecosystem engineers, such as ants, have important but occasionally unnoticed roles in regulating soil carbon cycles. However, little information is available pertaining to ant effects on changing molecular features of soil organic matter. In this study, we characterized total soil organic carbon (SOC), total nitrogen, water extractable organic carbon (WEOC) as well as molecular characteristics of humic acids (HAs) of ant mound soils (SoilAnt) and the surrounding soils (SoilCon) using pyrolysis-chromatography/mass (py-GC/MS). SOC, total nitrogen and WEOC contents of SoilAnt were significantly lower than those of SoilCon. SoilAnt samples had significant higher nitrogen containing compounds proportions in pyrolysis products of HAs as opposed to SoilCon samples. Another remarkable characteristic was that no polysaccharides, lignin, and phenols were identified in HAs of SoilAnt samples. It indicated that ant colonization significantly changed the molecular composition of soil organic matter.

Zhang, Z., Zhang, P., Li, Z., Kan, A.T., Tomson, M.B., 2018. Laboratory evaluation and mechanistic understanding of the impact of ferric species on oilfield scale inhibitor performance. Energy & Fuels 32, 8348-8357.


Scale inhibitor chemicals are widely used in oilfield operations for mineral scale control. However, the presence of iron species in oilfield produced water can considerably impair the performance of scale inhibitors. To date, few studies have been conducted to experimentally investigate the mechanism of iron effect on scale inhibitors. Although Fe(II) is the major form of iron species in oilfield produced water, Fe(III) can be formed in produced waters due to oxidation of Fe(II). In this study, Fe(III) effect on various scale inhibitors was evaluated by examining the inhibitor performance to control barium sulfate (barite) scale formation. This study finds that Fe(III) can significantly impair the performance of both phosphonate and polymeric inhibitors with an iron concentration below 1 mg L–1. Moreover, the mechanism of the influence of Fe(III) on scale inhibitors was studied by investigating the adsorption capacity of ferric hydroxide solid of phosphonate scale inhibitor and also

examining the efficacy of the unadsorbed inhibitor in aqueous solution. It can be concluded that the Fe(III) impact on phosphonate inhibitor is due to the adsorption of inhibitor to the surface of ferric hydroxide solids. Furthermore, two common chelating chemicals (EDTA and citrate) were tested for their effects in reversing the adverse impact of Fe(III) on scale inhibitor. Experimental results suggest that citrate is more effective than EDTA in reversing the detrimental impact of Fe(III) despite the fact the EDTA is a stronger chelating agent. The mechanisms of these two chelating chemicals in terms of interacting with Fe(III) were discussed and compared. This study provides the theoretical basis and technical insights for oilfield iron control to minimize iron impairment on scale inhibitor performance.

Zhao, B., Zhang, Y., Huang, X., Qiu, R., Zhang, Z., Meyers, P.A., 2018. Comparison of n-alkane molecular, carbon and hydrogen isotope compositions of different types of plants in the Dajiuhu peatland, central China. Organic Geochemistry 124, 1-11.


Long chain n-alkanes preserved in peat deposits have been widely used to reconstruct paleoenvironmental and paleoecological changes. However, our knowledge of how the leaf wax molecular and isotopic compositions of peat sequences might respond to changes in plant communities is limited. This study investigates the n-alkane molecular, carbon and hydrogen isotopic compositions of plant species collected from the Dajiuhu peatland, central China. The results show that forb and graminoid plants growing in peatlands have a relatively higher carbon preference index of long-chain n-alkanes than shrubs, ferns and aquatic plants. The δ13C values of individual n-alkanes generally decrease with increasing chain lengths, and different plant groups have similar δ13C values of C31 and C33 n-alkanes. An exception is Sphagnum, which has more negative δ13C values of C23 and C25 than those of its longer chain length homologues. Relative to peat pore water δD values in different seasons and different peat depths, the Dajiuhu plants normally exhibit relatively large hydrogen isotope fractionations, and the fractionations gradually increase from graminoid to forb to shrub. Taken together, these results highlight the influence of different kinds of vegetation on the collective molecular and isotopic ratios of n-alkanes in peat deposits.

Zhao, J., Ji, Y., Wu, Y., 2018. Reliability experiment on the calculation of natural gas hydrate saturation using acoustic wave data. Natural Gas Industry B 5, 293-297.


In this paper, compression wave velocity, shear wave velocity and their change during the formation of natural gas hydrate in unconsolidated sand and mud sediments were measured through petrophysical experiments to discuss the reliability of calculating natural gas hydrate saturation by using acoustic velocity data. Then, a computation model of natural gas hydrate saturation during the experiments was established based on the material balance equation, combined with the PVT (pressure, volume, temperature) state equation and its test conditions. On this basis, the changing law of the acoustic velocity of the unconsolidated sediments with the increase of natural gas hydrate saturation was analyzed. Finally, natural gas hydrate saturation was calculated by using the modified Lee's weight sonic formula, and was compared with that measured in the experiments. And the following research results were obtained. First, the acoustic data can be used to calculate the natural gas hydrate saturation when the content of natural gas hydrate reaches a certain extent. Second, the compression and shear wave velocities of unconsolidated sand and mud sediments increase with the rise of their natural gas hydrate content, and they are in a good relationship of linear correlation. And third, the natural gas hydrate saturation calculated based on the acoustic data is close to that measured

in the laboratory with much smaller errors. It is concluded that the research results provide a basis for the calculation of natural gas hydrate saturation using the actual acoustic logging data.



The sandstone-hosted Qianjiadian uranium deposit, hosted in the Upper Cretaceous Yaojia Formation in the Qianjiadian area, Songliao Basin, NE China, has been studied for over twenty years. However, there exists debate on whether mineralization fluid is low-temperature groundwater in favor of biogenic mineralization or diabase-related magmatic hydrothermal fluid for this deposit and other adjacent geologically linked sandstone-hosted uranium deposits (Baixingtu, Baolongshan and Huitianzhao deposits) in the North China. This study provided new data from petrographic and geochemical analyses, geochronology of uranium minerals (the EMPA chemical dating method) and petroleum hydrocarbon biomarkers in host sandstones. Two types of host sandstone were recognized. In calcareous sandstones, pitchblende coexists with colloform pyrite and poikilitic calcite cement while quartz and feldspars were extensively corroded. In non-calcareous sandstones, coffinite coexists with colloform pyrite and only feldspars were slightly corroded. This suggests that pitchblende formed in high pH (pH > ∼9) fluid, while the pH of ore-forming fluid for coffinite was lower (pH = 7–9). Besides, EMPA chemical dating revealed two stages of uranium mineralization. Stage-A occurred in 43–28 Ma with pitchblende as the only uranium mineral species. Stage-B occurred in 19–3 Ma with the formation of both pitchblende and coffinite. The uranium mineralization was biogenic under low-temperature groundwater condition and thus not from a diabase-related mafic magmatic hydrothermal fluid based on the following lines of evidence: (i) some coffinite occurs as phosphorus-rich microorganism-like microspherules structure; (ii) pyrite aggregates were generated from bacterial sulfate reduction as indicated by the δ34S values as low as −41.4‰; (iii) calcite cement in calcareous sandstone contains only single phase aqueous inclusions, and have δ13C values as low as −11.2‰, indicating that part of the carbon was derived from organic matter oxidation; (iv) the organic matter oxidation is further supported by hydrocarbons extracted from petroleum inclusions within calcite cement, showing occurrence of C26–C31 17α, 21β 25-norhopanes, typically resulting from heavy biodegradation.

Zhao, S., Pu, W., Wei, B., Xu, X., 2019. A comprehensive investigation of polymer microspheres (PMs) migration in porous media: EOR implication. Fuel 235, 249-258.


A type of polymer microspheres (PMs) with superior dispersity, swelling, elasticity, and saline and temperature resistance was prepared in this work through inverse emulsion polymerization. It was observed that these PMs experienced elastic deformation and obstructed micro-pores by means of complete, single and bridge plugging, and thus causing additional flow resistance. The migration modes of the PMs in porous media could be defined as smooth pass, elastic plugging-remigration incorporating low-efficiency and high-efficiency plugging, and complete plugging, on the basis of matching coefficients between the PMs and pore geometry. The plugging capability of the PMs was largely dependent on the matching coefficients. Interestingly, it was found that if appropriate matching coefficients was obtained, the PMs with higher elastic modulus showed an enhanced plugging capability even with smaller particle size. In addition, the results of adsorption and desorption behaviors of the PMs implied that the adsorbed PMs partially detached as a result of

caused flow fluctuation and decline/disappearance of secondary adsorption potential well. It is believed that the proposed PMs could be a viable, robust and promising candidate for conformance control and oil recovery improvement.



The Ordos Basin is a significant gas-producing region in China. Previous studies have shown that a large amount of the gas discovered in the upper Paleozoic strata originated from Carboniferous–lower Permian coal and its interbedded coal measure mudstone. To compare the hydrocarbon generation characteristics and process, two coal and coal measure mudstone samples from the Shanxi Formation in the Shenfu area were used in confined gold tube pyrolysis experiments. The analytical results revealed that both samples had poor oil generation potential, with maximum C6+ yields of 171.65–175.67 mg/g TOC for the coal and 50.12–51.86 mg/g TOC for the coal measure mudstone at the heating rate of 2 °C/h and 20 °C/h. However, their gas generation potentials are good, and the coal exhibited higher values than the mudstone, with final laboratory C1–C5 yields of 154.71–173.32 mg/g TOC for the coal and 82.52–98.96 mg/g TOC for the coal measure mudstone. Based on a comprehensive analysis of the indicators lnC2/C3, lnC1/C2 and δ13C1–δ13C2, the hydrocarbon generation process can be divided into three stages. The results of extrapolation to geological conditions revealed that the main gas generation stages of both source rocks in the Shanxi Formation began in the Early Cretaceous. Because of the regional tectonic uplift and the decrease in the geothermal gradient in the Late Cretaceous, the C1–C5 volume yields of the coal and the coal measure mudstone reached plateaus of 78.4 ml/g TOC and 32.7 ml/g TOC, respectively, in the Late Cretaceous, and the current transformation ratios of C1–C5 for the coal and the coal measure mudstone are only 32.1% and 22.8%, respectively.

Zheng, D., Chang, S.-C., Perrichot, V., Dutta, S., Rudra, A., Mu, L., Kelly, R.S., Li, S., Zhang, Q., Zhang, Q., Wong, J., Wang, J., Wang, H., Fang, Y., Zhang, H., Wang, B., 2018. A Late Cretaceous amber biota from central Myanmar. Nature Communications 9, Article 3170.

https://doi.org/10.1038/s41467-018-05650-2

Insect faunas are extremely rare near the latest Cretaceous with a 24-million-year gap spanning from the early Campanian to the early Eocene. Here, we report a unique amber biota from the Upper Cretaceous (uppermost Campanian ~72.1 Ma) of Tilin, central Myanmar. The chemical composition of Tilin amber suggests a tree source among conifers, indicating that gymnosperms were still abundant in the latest Campanian equatorial forests. Eight orders and 12 families of insects have been found in Tilin amber so far, making it the latest known diverse insect assemblage in the Mesozoic. The presence of ants of the extant subfamilies Dolichoderinae and Ponerinae supports that tropical forests were the cradle for the diversification of crown-group ants, and suggests that the turnover from stem groups to crown groups had already begun at ~72.1 Ma. Tilin amber biota fills a critical insect faunal gap and provides a rare insight into the latest Campanian forest ecosystem.

Zheng, J., Huang, C., Wang, S., 2018. Challenging pharmaceutical analyses by gas chromatography with vacuum ultraviolet detection. Journal of Chromatography A 1567, 185-190.


Vacuum ultraviolet (VUV) detector for gas chromatography (GC) provides qualitative spectral information from 125 nm to 240 nm. In this article, this information was applied to facilitate the development of a GC method for challenging pharmaceutical applications. Seven organic solvents were screened for trace level water content using VUV detection at 168 nm, and the results were used to identify n-hexane as a suitable diluent for 4-ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO), a water reactive compound. Selective detection of compounds of interest was demonstrated by varying detection wavelengths. All compounds were detected at 145 nm except for one unknown impurity, which co-eluted with n-hexane solvent. This impurity was detected at 225 nm, where n-hexane has no absorbance. In addition, the VUV spectra were used to: 1) accurately track peaks during early method development; 2) detect co-eluting peaks; 3) match peak identity in a sample vs. a standard; and 4) assess peak purity. With the universal detectability, qualitative spectral information and ease of use, VUV will become a versatile tool for GC for both method development and routine analysis.



Nuclear magnetic resonance (NMR) has been widely used to evaluate the pore size distribution (PSD) properties of coals. However, the NMR signal itself only provides a relative distribution of pore size. To calculate an absolute pore size distribution from the NMR data, the T2 cutoff value needs to be known. Meanwhile, the T2 cutoff value is an indicator to divide the irreducible fluid and movable fluid in porous rock and a key factor for permeability prediction. Conventionally, the T2 cutoff value is obtained by centrifugal experiments, the process of which is complicated and time consuming, and some T2 cutoff value prediction models are not suitable for coals with complex pore structures. Hence, a new method is needed for T2 cutoff value prediction. In this study, we performed scanning electron microscopy (SEM), low-temperature nitrogen adsorption/desorption (LTNA) and NMR experiments on 12 coal samples. The results of SEM and LTNA reveal the complex pore structures of the coals. According to the results from centrifugal experiments, the T2 cutoff value is in the range from 0.5–2.8 ms for subbituminous coals, whereas it is 15–32 ms for anthracite coals. We present a fractal theory based method for T2 cutoff value prediction. Using the estimated T2 cutoff values, we calculated the movable porosities, PSD and permeability for the selected coals. The results show that the proposed permeability model provides significantly better permeability estimation than classic (Coates and SDR) models. These methods are applicable not only for coals, but also for other unconventional gas reservoir rocks such as gas shales.



Identification of pyrolysis intermediates and products is of great significance to better understanding of a pyrolysis process and therefore its further upgrade to practical fuels. We hereby report a real-time analysis of pyrolysis volatiles of biomass in a micro fixed-bed reactor via an on-line near-atmospheric pressure photoionization Orbitrap mass spectrometry (nAPPI Orbitrap MS). The mass spectra suggest the pyrolysis products bear a molecular weight in the range of m/z 50–300. The oxygenated compounds having between 1 and 5 oxygen atoms and with double bond equivalent (DBE) values

ranging from 2 to 7 account for more than 90% of the identified peaks, indicating that significant upgrading should be developed towards applications. Pyrolysis products could be clearly distinguished from different components of biomass in the van Krevelen diagrams and DBE versus carbon number plots. The results from the nAPPI Orbitrap MS are further compared to those of off-line pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) and on-line single photoionization mass spectrometry (SPI-MS). The nAPPI Orbitrap MS is a powerful on-line approach with high sensitivity, ultrahigh-resolution, and no condensation or preparation. This analytical protocol is expected to be helpful in complicated thermochemical conversion studies, e.g. pyrolysis of biomass.

Zhou, Z., Pan, J., Wang, F., Gu, J.-D., Li, M., 2018. Bathyarchaeota: globally distributed metabolic generalists in anoxic environments. FEMS Microbiology Reviews 42, 639-655.


Bathyarchaeota, formerly known as the Miscellaneous Crenarchaeotal Group, is a phylum of global generalists that are widespread in anoxic sediments, which host relatively high abundance archaeal communities. Until now, 25 subgroups have been identified in the Bathyarchaeota. The distinct bathyarchaeotal subgroups diverged to adapt to marine and freshwater environments. Based on the physiological and genomic evidence, acetyl-coenzyme A-centralized heterotrophic pathways of energy conservation have been proposed to function in Bathyarchaeota; these microbes are able to anaerobically utilize (i) detrital proteins, (ii) polymeric carbohydrates, (iii) fatty acids/aromatic compounds, (iv) methane (or short chain alkane) and methylated compounds, and/or (v) potentially other organic matter. Furthermore, bathyarchaeotal members have wide metabolic capabilities, including acetogenesis, methane metabolism, and dissimilatory nitrogen and sulfur reduction, and they also have potential interactions with anaerobic methane-oxidizing archaea, acetoclastic methanogens and heterotrophic bacteria. These results have not only demonstrated multiple and important ecological functions of this archaeal phylum, but also paved the way for a detailed understanding of the evolution and metabolism of archaea as such. This review summarizes the recent findings pertaining to the ecological, physiological and genomic aspects of Bathyarchaeota, highlighting the vital role of this phylum in global carbon cycling.

Zhu, Q.-F., Yan, J.-W., Zhang, T.-Y., Xiao, H.-M., Feng, Y.-Q., 2018. Comprehensive screening and identification of fatty acid esters of hydroxy fatty acids in plant tissues by chemical isotope labeling-assisted liquid chromatography–mass spectrometry. Analytical Chemistry 90, 10056-10063.


Fatty acid esters of hydroxy fatty acids (FAHFAs) are a new class of lipid mediators with promising anti-diabetic and anti-inflammatory properties. Comprehensive screening and identification of FAHFAs in biological samples would be beneficial to the discovery of new FAHFAs and enable greater understanding of their biological functions. Here, we report the comprehensive screening of FAHFAs in rice and Arabidopsis thaliana by chemical isotope labeling-assisted liquid chromatography–mass spectrometry (CIL-LC–MS). Multiple reaction monitoring (MRM) was used for screening of FAHFAs. With the proposed method, we detected 49 potential FAHFA families, including 262 regioisomers, in tissues of rice and Arabidopsis thaliana, which greatly extends our knowledge of known FAHFAs. In addition, we proposed a strategy to identify FAHFA regioisomers based on their retention on a reversed-phase LC column. Using the proposed identification strategy, we identified 71 regioisomers from 11 FAHFA families based on commercial standards and characteristic chromatographic retention behaviors. The screening technique could allow for the

discovery of new FAHFAs in biological samples. The new FAHFAs identified in this work will contribute to the in-depth study of the functions of FAHFAs.

Zoccali, M., Giuffrida, D., Salafia, F., Giofrè, S.V., Mondello, L., 2018. Carotenoids and apocarotenoids determination in intact human blood samples by online supercritical fluid extraction-supercritical fluid chromatography-tandem mass spectrometry. Analytica Chimica Acta 1032, 40-47.


A direct on-line method based on the coupling of supercritical fluid extraction and supercritical fluid chromatography with triple quadrupole mass spectrometry detection (SFE-SFC-QqQ/MS) for selected carotenoids determination and apocarotenoids detection in intact human blood was developed for the first time. Carotenoids and apocarotenoids were identified by using the available standard together with full scan, selected ion monitoring (SIM), and multiple reaction monitoring (MRM) experiments. Moreover, β-Cryptoxanthin, Zeaxanthin, β-Carotene and Capsanthin were directly quantified by the developed methodology, using a multiple reaction monitoring (MRM) approach; the determined average content of β-carotene was 123.8 nmol L−1 (range 18.7–485.1 nmol L−1), of β-cryptoxanthin was 385.3 nmol L−1 (range 72.5–1920.3 nmol L−1), of zeaxanthin was 396.9 nmol L−1 (range < LoD – 1795.8 nmol L−1) and of capsanthin was 38.9 nmol L−1 (range < LoD – 188.4 nmol L−1). Analyses were carried out on 10 μL aliquots of intact blood samples without any preliminary treatment; the online extraction and chromatographic separation time was just over 20 min. The method was validated in terms of linearity, precision, limits of detection and quantification, and accuracy. Interestingly, β-apo-12′-carotenal, apo-10′-zeaxanthinal, apo-12′-zeaxanthinal, apo-14′-zeaxanthinal, ε-apo-8-luteinal, ε-apo-12-luteinal and ε-apo-14-luteinal were detected in human blood, together with two zeaxanthin fatty acid esters, for the first time.

Zou, J., Rezaee, R., Yuan, Y., 2018. Investigation on the adsorption kinetics and diffusion of methane in shale samples. Journal of Petroleum Science and Engineering 171, 951-958.


Shale gas is becoming increasingly important to mitigate the energy crisis of the world. Understanding the mechanisms of gas transport in shale matrix is crucial for development strategies. In this study, methane adsorption kinetics in shale samples were measured under different pressures and temperatures. The results of methane adsorption rate were fitted by the bidisperse diffusion model. Pore structure of the shale samples were characterized by low-pressure N2 and CO2 adsorption. The results showed that pressure has a negative effect on methane adsorption rate and diffusion, while the effect of temperature is positive. Combining the total organic carbon (TOC) and pore structure, methane adsorption rate and effective diffusivity were compared between all the shale samples. The methane adsorption rate under high pressure (50bar) is positively related to the TOC content. The micropore volume showed a moderate positive relation with the methane adsorption rate at 30bar. A weak positive relation exists between the TOC and effective diffusivity at low pressure and the effective diffusivity at low pressure shows an increasing trend with micropore(<2 nm) volume. A hypothetic pore model is proposed: micropore in shales controls gas diffusion as pore throat which connects pores.



The accurate and precise mass spectrometric measurement of organic compounds in atmospheric aerosol particles is a challenging task that requires analytical developments and adaptations of existing techniques for the atmospheric application. Here we describe the development and characterization of an atmospheric pressure chemical ionization Orbitrap mass spectrometer (APCI-Orbitrap-MS) for the measurement of organic aerosol in real time. APCI is a well-known ionization technique, featuring minimal fragmentation and matrix dependencies, and allows rapid alternation between the positive and negative ionization mode. As a proof of principle, we report ambient organic aerosol composition in real-time, with alternating ionization, high mass resolution (R = 140 000) and accuracy (<2 ppm). The instrument was calibrated in the negative ion mode using 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA) model aerosol. We obtain a detection limit of 1.3 ng/m3. Based on the performed calibration using MBTCA particles, the ambient concentration of MBTCA in the particle phase measured in an urban area in Mainz, Germany, ranged between 10 and 80 ng/m3. For the first time, we apply a nontarget screening approach on real-time data, showing molecular variability between ambient day- and nighttime aerosol composition. The detected compounds were grouped in the night- and daytime and analyzed by ultrahigh-resolution MS (UHRMS) visualization methods. Among several prevalent biogenic secondary organic aerosol (BSOA) markers, 24 organic mononitrates and one organic dinitrate were detected. We further estimate that, on average, organic nitrates contribute to 5% and 14% of the measured particulate organic aerosol at day and night, respectively.

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