OLR (1987) 34 (9) C. Chemical Oceanography 753

Phase analysis was applied to Fe, Mn, A1, Ti, Cr, V, Zn, Cu, Ni, Co, Zr, Ga, Yb and Y in 69 specimens from surface layers of Pacific sediments. All the elements show decreases in percent lithogenic form and increases in the hydrogenic form as sediment types change away from the land. There are three zones showing high rates of hydrogenic accumula- tion: nearshore, equatorial, and sub-Antarctic. The metalliferous sediments of the EPR show large amounts of Fe, Mn, V, Zr, Ni, and Co. Inst. of Oceanol., Acad. of Sci., Moscow, USSR.

87:5013 Martin, J.H., G.A. Knauer, D.M. Karl and W.W.

Broenkow, 1987. VERTEX [Vertical Transport and Exchange]: carbon cycling in the northeast Pacific. Deep-Sea Res., 34(2A):267-285.

Particulate organic C fluxes were measured with free-floating particle traps, and the data indicated relatively little spatial variability in open ocean fluxes. To obtain mean rates representative of the oligotrophic environment, flux data from six stations were combined and fitted to a normalized power function. Comparisons with the literature indicate that trap-derived new productivities in the open Pacific are substantially less than those estimated for the Sargasso Sea. A hypothesis is presented to explain this discrepancy and the data are also used for various global estimates. Moss Landing Mar. Lab., Moss Landing, CA 95039, USA.

87:5014 Morse, J.W., F.J. Millero, J.C. Cornwell and David

Rickard, 1987. The chemistry of the hydrogen sulfide and iron sulfide systems in natural waters. Earth-Sci. Rev., 24(1):1-42.

The basic inorganic chemistry of authigenic sulfide minerals (mostly iron sulfides) and associated dis- solved species in anoxic marine basins and sediments is reviewed. Dept. of Chem. Oceanogr., Texas A&M Univ., College Station, TX 77843, USA. (gsb)

87:5015 Smith, K.L. Jr., A.F. Carlucci, R.A. Jahnke and D.B.

Craven, 1987. Organic carbon mineralization in the Santa Catalina Basin. Benthic boundary layer metabolism. Deep-Sea Res., 34(2A):185- 211.

Organic carbon mineralization rates in the benthic boundary layer (1300 m depth) were estimated to identify the primary sites and organisms involved in the turnover of carbon and to compare these rates with the supply of particulate organic matter entering the system from above. Concurrent in-situ measurements of macrozooplankton, epibenthic

megafauna, and sediment community oxygen con- sumption, and bacterioplankton and total microbial (microplankton) metabolism were made on 12 dives with DSRV Alvin in November 1984. Pore water and solid phase chemistries, and sediment microbial activity were measured on samples from box cores. Scripps Inst. of Oceanogr., Univ. of Calif., La Jolla, CA 92093, USA.

87:5016 Top, Z., W.B. Clarke and W.J. Jenkins, 1987.

Tritium and primordial 3He in the North Atlantic: a study in the region of Chariie-Gibbs Fracture Zone. Deep-Sea Res., 34(2A):287-298.

The plume of primordial 3He seen at a depth of about 3 km in the North Atlantic during the GEOSECS program in 1972 was observed again in the vicinity of the Charlie-Gibbs Fracture Zone. Most evidence suggests that the fracture zone is not the source of this helium, but no feasible alternative can be identified. Three distinct cores of high tritium water (Labrador Sea, Denmark Straits and Iceland- Faroes waters) as well as evidence of recirculated Antarctic Bottom Water-Denmark Straits Water near the floor of the western extremity of the fracture zone were observed. Tritium concentrations across this section are everywhere in excess of pre-nuclear era levels. RSMAS, Univ. of Miami, FL 33149, USA.

87:5017 Williams, P.M., E.R.M. Druffel and K.L. Smith Jr.,

1987. Dietary carbon sources for deep-sea organ- isms as inferred from their organic radiocarbon activities. Deep-Sea Res., 34(2A):253-266.

A small but significant depletion of radiocarbon activity is present in fishes and crustaceans collected throughout the water column in the north central and northeast Pacific compared to average values for DIC and zooplankton found in the euphotic zone during the same period. These low ~4C activities are postulated to result from (1) the ~4C gradient in DIC in the euphotic zone, and (2) the incorporation of low activity, pre-bomb peak carbon (pre-1969) from the surface ocean into chronologically old organ- isms. Data suggest that the main source of dietary carbon for deep-sea organisms is from rapidly sinking organic detritus from the surface and from active (animal-mediated) transport of living carbon. There may be a minor contribution (~15%) to bathypelagic organisms from chemolithotrophically derived organic carbon, from heterotrophic uptake of mid-depth DIC or from recycled carbon. Scripps Inst. of Oceanogr., La Jolla, CA 92093. USA.