Geological, geochemical and biogeochemical data on boundary zones of the Atlantic Ocean

Results of studies in two biogeochemically active zones of the Atlantic Ocean (the Benguela upwelling waters and the region influenced by the Congo River run-off) are reported in the book. A multidisciplinary approach included studies of the major elements of the ocean ecosystem: sea water, plankton, suspended matter, bottom sediments, interstitial waters, aerosols, as well as a wide complex of oceanographic studies carried out under a common program. Such an approach, as well as a use of new methodical solutions led to obtaining principally new information on different aspects of oceanology.

Properties, sedimentation and accumulation rates, and chemical composition of bottom sediments from the Deryugin Basin, Sea of Okhotsk

Results of a study of contents and accumulation rates of Fe, Mn, and some trace elements in Upper Quaternary sediments of the Deryugin Basin are presented. Maps of average contents and accumulation rates of excessive Fe, Mn, Zn, Ba, Ni, Pb, Cu, and Mo in sediments of the first oxygen isotope stage (OIS) have been plotted. Anomalous contents and accumulation rates are confined to peripheral zones of the Deryugin sedimentary basin and large fracture zones. Different mechanisms of influence of fluid-dynamic processes on rate of hydrogenic and biogenic accumulation of ore elements are assumed.

Geochemistry, mineralogy and isotopes at DSDP Hole 62-464

The relationships between mineralogical and geochemical data on the three successive sedimentary facies at Deep Sea Drilling Project Site 464 are studied. The evolution of siliceous biogenic sediments is derived from the analyses of one Fe-Ti smectite concretion, and of siliceous aggregates occurring in the pelagic "brown clays." Along the sedimentary section, the trace elements enriching the authigenic silicates and the Fe-Mn oxyhydroxides vary, depending on the marine environment. The proportion of clays and carbonates into the siliceous deposits controls the diagenetic evolution of silica making up the quartz aggregates from the "brown clay" or the cristobalite cherts.