early proterozoic pillow lavas of suisari as habitats of the earliest microorganisms

ISSN 0031�0301, Paleontological Journal, 2013, Vol. 47, No. 10, pp. 1110–1115. © Pleiades Publishing, Ltd., 2013.

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INTRODUCTION

The development of life in volcanogenic rocks ofthe remote past and colonization by microorganisms(both ancient and modern) of the boundary (surface)between the volcanogenic rock and water (deposits)are presently widely debated (Rasmussen, 2000; Fisket al., 2003, 2006; Furnes et al., 2004, 2007;McLoughlin, 2007; Astafieva et al., 2008, 2009a,2009b; Rozanov and Astafieva, 2009). The modernmicrobial life has been recorded in both surface rocksand deep underground. As commonly believed, mostof the biomass of microorganisms of the Earth occur inunderground habitats. Microorganisms dwell in dampcracks of volcanogenic rocks and are recorded byimprints in the rock or by chemical remains of the vitalactivity. On the other hand, in near�surface condi�tions, modern microbial life is frequently closely con�nected with the volcanogenic rock–water interface(Fisk et al., 2006).

Volcanogenic and volcanogenic–sedimentaryrocks (where the surfaces of the volcanogenic rock–water interface boundaries occur) of the Archeangreenstone belts (GSB) of western Greenland, SouthAfrica, and Australia are the most ancient terrestrialrocks, which enclose microfossils.

The most ancient extinct microorganisms con�nected with this interface were described from Meso�Archean pillow lavas of the Barberton GreenstoneBelt in South Africa. It was proposed that microbesoccupied these underwater effusive rocks just aftereruption about 3.5 Ga (Furnes et al., 2004). Schopf(1993) was the first to discover fossil filamentousmicroorganisms resembling cyanobacteria in the EarlyArchean (3.465 Ga) rocks of western Australia. The

criticism of these early finds (Brasier et al., 2002)seems to have little force. Another record of Archean(3.235 Ga) microfossils in volcanogenic rocks comesfrom the sulfide volcanogenic strata in the PilbaraCraton in Australia. In this case, bacteria wererecorded in a system of underwater thermal springs(Rasmussen, 2000).

It is known that pillow lavas are formed as a resultof underwater flow of basalt lavas. Sometimes, pillowsreach several meters in thickness. In cross sections ofpillows, the external rapidly solidifying glassy crustand more devitrified internal core, often containingradial aggregates, are clearly visible. Gaps betweenlava pillows are filled with either sedimentary matteror products of lava disruption, small glassy debris. Fos�sil bacterial assemblages from different parts of pillowlavas have not been compared; therefore, it is urgent tostudy the distribution of microorganisms in solidifiedpillow lavas. The study of microfossils from the glassymatrix of Early Paleoproterozoic pillow lavas and theircomparison with extant forms suggest that recent andancient basaltic glasses of pillow lavas contain ratherdiverse microbial assemblages. It has been shown thatboth assemblages are dominated by various filamen�tous taxa and contain forms tentatively referred to pra�sinophytes, i.e., eukaryotes. At the same time, cocciand oval forms were probably subordinate (Astafieva etal., 2009). It was also corroborated that microorgan�isms colonized the basalt glass of Early Precambrianunderwater eruptions, as do extant microorganisms,colonizing modern volcanic glass. The present study isdevoted to prokaryotic assemblages from the interpil�low debris, as well as marginal and internal parts of pil�

Early Proterozoic Pillow Lavas of Suisari As Habitats of the Earliest Microorganisms

M. M. Astafievaa, A. A. Chistyakovb, M. M. Boginab, and E. V. Sharkovb

aBorissiak Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya ul. 123, Moscow, 117997 Russiae�mail: [email protected]

bInstitute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (IGEM), Russian Academy of Sciences, Staromonetnyi per. 35, Moscow, 109017 Russia

e�mail: [email protected] June 19, 2012

Abstract—Assemblages of fossilized microorganisms from the Paleoproterozoic Suisarian Formation(Ludicovian stratotype of the Karelian Complex) of central Karelia are recognized and investigated. Fossilassemblages of microorganisms confined to different zones of pillow lavas are compared.

Keywords: microorganisms, bacteria, cyanobacteria, eukaryotes, Proterozoic, pillow lavas

DOI: 10.1134/S0031030113100055

PALEONTOLOGICAL JOURNAL Vol. 47 No. 10 2013

EARLY PROTEROZOIC PILLOW LAVAS OF SUISARI 1111

lows as exemplified by the Paleoproterozoic basalticpillow lavas from central Karelia.

MATERIAL

The material includes assemblages of fossilizedmicroorganisms from the Paleoproterozoic SuisarianFormation (Ludicovian stratotype of the KarelianComplex (Resolution of the III All�Russia …, 2001)dated about 2.0 Ga) of the Onega Basin in centralKarelia. The Suisarian Formation is composed ofpicrite and picrobasalt, basalt, trachybasalt and theirtuffs, and terrigenous deposits. Pillow lavas (marginaland central parts and interpillow matter) from twolocalities were examined.

(1) A locality on the Kel’tnavolok Cape (Fig. 1),the northernmost cape of Suisari Island, is situated in

the southeastern Kondopoga Gulf of Lake Onega. Pil�low lavas of plagioclase porphyry basalt, with a moreor less pronounced variolitic structure outcrop there.The pillows consist of the aphanitic chill zone, mar�ginal and central (core) zones. The last is composed ofthe mostly devitrified matter and frequently containsgas cavities, which are sometimes filled with chalce�dony and quartz matter.

(2) A locality in the upper part of the Suisarian For�mation section of the Yalguba Range is situated on thebank of Lake Onega, opposite the village of Yalguba,approximately 20 km northeast of the city of Petroza�vodsk (Fig. 1). The section is dominated by plagio�clase–pyroxene porphyry basalts with pillow units,which form 5–20�thick�m flows. These flows alter�nate with massive lava flows, ranging from 3–5 to 18–20 m in thickness.

Barents Sea

Kola Peninsula

White Sea

Lake Onega

Ladoga

Suisari Island

Yalguba

La

ke

O

ne

ga

P e t r o z a v o d s k Ba y

Petrozavodsk

1 2 3 4

5 6 7

40° 70°

60° 30°

40°

70°

60°

30°

Fig. 1. Scheme of geological structure of the northwestern Onega Region, with the object investigated (encastre). Paleoprotero�zoic: (1) Suisarian Formation, (2) Shoksha Formation, (3) Padosska Formation, (4) Zaonega Formation, (5) gabbro�dolerites ofthe Padosska Formation; (6) Quaternary beds; (7) sampling localities.

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ASTAFIEVA et al.

Bacterial paleontological studies were performedusing a CamScan�4 scanning electron microscope,with a Link�860 microanalyzer. Only fresh chips ofrocks were examined.

RESULTS

Bacterial paleontological studies have shown thatthe marginal regions of pillows and interpillow matterare dominated by filamentous fossils. Biofilms alsoplay an important role among fossilized remains understudy. Note that descriptions only concern fossilizedbacteria (cyanobacteria) or, more precisely, pseudo�morphs of bacteria and cyanobacteria.

Marginal Regions of Pillows with Interpillow Matter

These zones have yielded diverse microfossils,including:

Filamentous forms. They are sometimes very abun�dant, forming an impression that they compose partic�ular elements of the rock. This suggests that bacteriacolonized the surface of cooling lava simultaneouslywith sedimentation. Fossil filamentous forms some�times co�occur with coccoid forms (Pl. 1, fig. 1). Thefilaments are long, up to 100 µm long or even longerand about 2 µm thick. The cocci are about 3–4 µm indiameter.

The rock contains complete cavities filled withinterlacing fossilized bacterial filaments. Bacteriaapparently inhabited the surface of pillows during theformation of the interpillow matter.

There are also pseudomorphs of solitary filaments(Pl. 1, fig. 2), which are usually at most 3 µm thick andmore than 20 µm long. Some pseudomorphs arelarger, up to 10 µm thick, and some are short tubular(Pl. 1, fig. 3). Moreover, it seems that, on the left of atubule (4b, arrow), there is an imprint of the sametubular form (4b, double arrow) and that the entirerock fragment is composed of small (up to 1 µm)cocci.

The sample contains many holes, which are some�times partially filled with rock and probably representsections of filamentous forms (Pl. 1, fig. 4). Some sec�tions of filaments (about 10 µm in diameter) are halffilled by enclosing rock, with a thick (about 1.5 µm)heterogeneous cover (Pl. 1, fig. 4). Filaments ofsmaller diameter (about 5 µm) are also present; theircovers are rather dense, about 1 µm thick (Pl. 1, fig. 5).Many filaments are apparently completely embeddedin the rock (Pl. 1, figs. 4, 5), thus, suggesting theirundoubted in situ formation. In places, the matter isapparently composed of abundant small (up to 1 µm)cocci (Pl. 1, fig. 4).

Judging from the size and morphology, all theforms in question are bacteria and (or) cyanobacteria.

Cocci are less frequent than filamentous speci�mens. They are mostly singular, have a rough surface,usually about 3–6 µm in diameter. Colonies of cocci

are rare. An accumulation of cocci about 3 µm indiameter is only recorded in glycocalyx, composing arock fragment (Pl. 1, fig. 6).

Biofilms and biofilm fragments are common (Pl. 2,fig. 1).

There are also larger (about 10 µm in diameter)spherical forms (Pl. 2, fig. 2), united in accumulations.Perhaps, these are planktonic forms deposited on thebottom. They are similar in morphology to prasino�phytes, although available data are insufficient formore precise identification. Since spherical formsusually compose rock units, they were apparently bur�ied simultaneously with sedimentation.

Marginal Zone of Pillows

Microfossils coming from the marginal zone of pil�lows are also rather diverse, including:

Isolated filamentous forms (Pl. 2, fig. 3) more than30 µm long and about 2 µm in diameter are present.Interlacing of filaments has not been recorded.

The holes produced by filaments and filled withenclosing matter are present (Pl. 2, fig. 4).

The cocci are extremely scarce (Pl. 2, fig. 5); theyare usually less than 3 µm in diameter. Only individualcocci are present, although they do not form colonies.

Biofilms are common (Pl. 2, fig. 6); some presum�able biofilm fragments are treated as flattened coversof cyanobacteria.

Central Part (Core) of Pillows

Basalts of pillow lavas enclose rare microfossils, inparticular, individual pseudomorphs of filaments,tubes, and cocci. However, these microfossils were notnecessarily buried in their lifetime, because all formslie on the rock surface, not embedded into the rock.

DISCUSSION AND CONCLUSIONS

Bacterial paleontological studies of various pillowlavas, including rocks from the interpillow space, mar�ginal and central zones, have shown significant differ�ences in the distribution of microfossils. The mainpoint is that microfossils from the interpillow spaceand marginal regions of pillows are much more abun�dant and diverse than those from the central parts(Table 1).

The chemical composition of fossilized organismscorresponds in all cases (interpillow matter, marginaland central parts of pillows) to the composition ofenclosing matter. This agrees with the in situ burial ofmicroorganisms and confirms the fact that we dealexclusively with pseudomorphs and almost completelyexclude the possibility of preservation of organic matter.

Pillow lavas of the Suisarian Formation were prob�ably formed in connection with repeated underwatereruptions; as a result, the earlier formed pillow lavaswere covered by products of later eruptions. The inter�



Plate 1

10 µm1 2 3 µm

3 µm43 10 µm

3 µm65 3 µm

E x p l a n a t i o n o f P l a t e 1

Microfossils from the marginal zones of pillows of pillow lavas with interpillow matter; central Karelia, Onega Basin, SuisariIsland; Paleoproterozoic, Suisarian Formation.Fig. 1. Interlacing filamentous forms against a background of cocci.Figs. 2 and 3. Fragments of filamentous forms: (2) thread fragment; (3) pseudomorph of filamentous (tubular) form and imprintof short and thick filamentous (tubular) forms.Figs. 4 and 5. Holes in the rock, traces of filamentous forms.Fig. 6. Coccus colony.

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Plate 2

10 µm1 10 µm2

10 µm3

10 µm4

3 µm5 3 µm6

E x p l a n a t i o n o f P l a t e 2

Microfossils from the marginal regions of pillows of pillow lavas with interpillow matter; central Karelia, Onega Basin, SuisariIsland; Paleoproterozoic, Suisarian Formation.Fig. 1. Biofilm fragment.Fig. 2. Spherical forms.Microfossils from the marginal zone of pillows of pillow lavas; central Karelia, Onega Trough, Suisari Island; Lower Proterozoic,Suisarian Formation.Fig. 3. Filamentous form.Fig. 4. Holes produced by filamentous forms filled with rock.Fig. 5. Individual coccoidal structure.Fig. 6. Biofilm fragment.



pillow matter was also formed in the Suisarian timeduring interruptions between eruptions. The distribu�tion of microfossils in pillow lavas (Table 1) shows thatthe most favorable conditions for the development andflourishing of life were in the deposits on the pillowlava surface, which gave rise to the interpillow matter.The marginal region of pillow lavas bordered bydeposits was also rather favorable for the developmentof microorganisms.

Thus, the present study corroborates the assump�tion that almost all oldest volcanogenic rocks arepromising for bacterial paleontological investigation.

ACKNOWLEDGMENTS

This study was supported by the Program of thePresidium of the Russian Academy of Sciences “Prob�lems of the Origin of Life and Formation of the Bio�sphere” (Subprogram 2), the Russian Foundation forBasic Research, project nos. 11�04�00129, 11�05�00695, and 12�04�00102, and the Russian State Pro�gram for Support of Leading Scientific Schools,project no. NSh�65493.2010.4.

We are sincerely grateful to all colleagues partici�pating in discussions and editing the manuscript andto A.V. Kravtsev and L.T. Protasevich for help inexamination using a CamScan�4 SEM.

REFERENCES

Astafieva, M.M., Rozanov, A.Yu., Cornell, D.H., andHoover, R.B., Development of Living Organisms on theLava–Water Interface of Palaeoproterozoic Ongeluk Lavasof South Africa, Proc. SPIE, 2008, vol. 7097, pp. 709703�1–709703�13.Astafieva, M.M., Rozanov, A.Yu., Sadovnikov, G.N., andSapova, E.V., Fossil Bacteria from the Permotriassic Trap�pean Strata of Siberia, Paleontol. J. (Moscow), 2009, vol. 43,no. 8, pp. 46–54.Astafieva, M.M., Rozanov, A.Yu., Sharkov, E.V., Chistya�kov, A.V., Bogina, M.M., and Hoover, R.B., VolcanicGlasses As Habitat for Microfossils: Evidence from theEarly Paleoproterozoic Pillow Lavas of Karelia and TheirModern Analogues in the Mid�Atlantic Ridge, Proc. SPIE,2009, vol. 7441, pp. 744104�1–744104�12.Brasier, M.D., Green, O.K., Jephcoat, A.P., et al., Ques�tioning the Evidence for Earth’s Oldest Fossils, Nature,2002, vol. 416, pp. 76–81.

Fisk, M.R., Storrie�Lombardi, M.C., Douglas, S.,Popa, R., McDonald, G., and Di Meo�Savoie, C., Evi�dence of Biological Activity in Hawaiian SubsurfaceBasalts, Geochem. Geophys. Geosyst., 2003, vol. 4,pp. 2003GC000387.Fisk, M.R., Storrie�Lombardi, M.C., and Josef, J., TheWater–Igneous Rock Interface: Potential Microbial Habi�tats on Mars, Tech. Abstr. Sum. Dig. Part Proc. SPIE, 2006,vol. 6309, p. 176.Furnes, H., Banerjee, N.R., Muehlenbachs, K.,Staudigel, H., and de Wit, M., Early Life Recorded inArchean Pillow Lavas, Science, 2004, vol. 304, pp. 578–581.Furnes, H., Banerjee, N.R., Staudigel, H.,Muehlenbachs, K., McLoughlin, N., de Wit, M., and vanKranendonk, M., Comparing Petrographic Signatures ofBoialteration in Recent to Mesoarchean Pillow Lavas:Tracing Subsurface Life in Oceanic Igneous Rocks, Pre�camb. Res., 2007, vol. 158, pp. 156–176.McLoughlin, N., Brasier, M.D., Wacey, D., et al., On Bio�genecity Criteria for Endolithic Microborings on Early Earthand beyond, Astrobiology, 2007, vol. 7, no. 1, pp. 10–26.Rasmussen, B., Filamentous Microfossils in a 3.235�Mil�lion�year�old Volcanogenic Massive Sulfide Deposit,Nature, 2000, vol. 405, pp. 676–679.Resolution of the III All�Russia Conference “GeneralQuestions of Stratification of the Precambrian”, Stratigr.Geol. Korrelyatsiya, 2001, vol. 9. no. 3, pp. 101–106Rozanov, A.Yu. and Astafieva, M.M., The Evolution of theEarly Precambrian Geobiological Systems, Paleontol.J. (Moscow), 2009, vol. 43, no. 8, pp. 61–77.Rozanov, A.Yu., Astafieva, M.M., and Hoover R.B., TheEarly Earth and Its Environments, Proc. SPIE, 2008,vol. 7097, pp. 709708�1–709708�15.Schopf, J.W., Microfossils of the Early Archean ApexChert: New Evidence of the Antiquity of Life, Science,1993, vol. 260, no. 5108, pp. 640–646.Staudigel, H. and Furnes, H., Microbial Mediation of Oce�anic Crust Alteration, in Hydrogeology of the Oceanic Crust,Cambridge: Cambridge Univ. Press, 2004, pp. 606–624.Thorseth, I.H., Furnes, H., and Heldal, M., The Impor�tance of Microbiological Activity in the Alteration of Natu�ral Basaltic Glass, Geochim. Cosmochim. Acta, 1992, vol. 56,pp. 845–850.Thorseth, I.H., Torsvik, T., Torsvik, V., Daae, F.L., andPedersen, R.B., Keldysh�98 Scientific Party, 2001: Diver�sity of Life in Ocean Floor Basalts, Earth Planet Sci. Lett.,2001, vol. 194, pp. 31–37.

Translated by G. Rautian

Table 1. Distribution (quantitative and qualitative) of microfossils in different parts of Early Proterozoic pillow lavas

Rock (sample)

Filamentous forms CocciSpherical

forms, 10 µm in diameter

Biofilmsinterlacing filaments

singularholes

of filaments

singular, 3 µm

in diametercoloniesup to 3 µm

in diameterup to 10 µm in diameter

Interpillow matter + +++ + ++ + + + +++Marginal zone of pillows – ++ – + + – – ++

Basalts – + – – + – –

early proterozoic pillow lavas of suisari as habitats of the earliest microorganisms

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