Composition of organic matter from black shales drilled in the Cape Verde Basin in DSDP Hole 41-367

Results of geochemical studies of organic matter in black shales from the Cape Verde Basin are reported. Based on these results, in combination with data of petrographic analysis, conclusions are made about sapropelic nature of their organic matter and low degree of its coalification. It corresponds to the proto-catagenetic substage of sedimentary rocks. Black shales of the Cape Verde Basin are classified as potential oil source strata.

Processing results from drill hole VNIIO-1988-Sht-01 on the shelf of the Barents Sea (Report 6404, Murmansk)

Interareal correlation has been carried out; composition of the deposits has been determined; sections recovered by marine drilling have been compared; reconstructed paleogeographic conditions confirm previous views on Jurassic and Cretaceous sedimentation in the area: 1. Determinate changes of continental and shallow marine mainly sandy Middle Jurassic deposits by sandy-clayey marine ones to the north and west occur. This indicates similar direction of clastic material migration and converse direction of Jurassic marine transgressions. 2. Increase of sand contents in the deposits also to the east and to the southeast indicates an important source of clastic material. It can result from incipience and development of the epiplatform orogen of Novaya Zemlya - Pai-Khoi in the Late Triassic - Early Jurassic. 3. Compositional and facial changes as well as changes in thicknesses of some Early Cretaceous lithologic-stratigraphic complexes indicate fast change of terrigenous material transport from the north to the south - south-east in the Late Valanginian - Hauterivian. Besides within the South Barents Sea region up to the Shtokman area there occurs weak variability in lithologic parameters of Neocomian avandeltaic deposits and turbidites composed of clays, claystones, and clayey siltstones. Correlation of drilling sections from the Shtokman area and from the South Basin of the Barents Sea together with paleotectonic analysis result to the conclusion about significant structure-forming movements in the Late Jurassic - Early Neocomian. During this time there occurred maximal growth of the Shtokman structure and likely of many other structures belonging to the South Basin of the Barents Sea.

Composition of organic matter in bottom sediments from the Antarctic sector of the Atlantic Ocean

We identify geochemical features of sedimentary organic matter in various morphostructural zones of the Antarctic sector of the Atlantic. We present background geochemical organic parameters for shelf and deep-sea sediments from the Weddell and Scotia Seas and the Bransfield Strait. Geochemical organic parameters are good indicators of environmental and facial variations in sediments and could be used for environmental monitoring of the World Ocean.