Composition of organic matter in suspended matter and bottom sediments of the southeastern Baltic Sea

Data on contents and compositions of hydrocarbons (HCs)-aliphatic (AHCs) and polycyclic aromatic (PAHs) are provided in comparison with contents of total organic carbon (Corg), lipids in suspended matter, and Corg in bottom sediments. Particular attention is paid to distribution of HCs in the area of the Kravtsov oil field. It is established that concentrations of AHCs in water are governed by concentrations of suspended matter and elevated AHC concentrations are confined to coastal areas. In the area of D-6 platform sandy bottom sediments are notable for great variability of HC concentrations, both laterally and from year to year. In summer of 2010 average content of AHCs was 40 ppm (19% of Corg) and that of PAHs was 0.023 ppm. Natural seepage from sediment mass is considered to be a source of HCs along with oil contamination.

Composition of rocks, minerals, water, and gases from uplift areas of the Central Atlantic

Original geological, geophysical, lithological, mineralogical data on uplifts of the Central Atlantic are given in the book based on materials of Cruise 1 of the R/V Akademik Nikolaj Strakhov. Geological and geophysical studies include description of the obtained material and analysis of structural and morphological elements of the ocean floor. Results of lithological, petrochemical and geochemical studies were extremely innovative and develop a conceptual model. The latter include studies of petrochemical evolution of tholeiitic alkaline plate volcanism, large-scale hydrothermal transformation of basement rocks - palygorskitization, phosphatization and ferromanganese mineralization. Showing imposition Superposition of hydrogenic alteration on hydrothermally altered rocks and its role in Cenozoic history of sedimentation is shown.

Composition of bottom sediments from the Guinea Basin

Geomorphology of the Guinea Basin is described along with sediments from cores collected on the abyssal plain, within the abyssal hill zone, and in the eastern part of the Chain Fracture Zone. Stratigraphic differentiation of deep-sea sediments was based on diatom analysis, geochemical and lithological data. Holocene and Pleistocene were identified by these criteria. The lower boundary of Holocene is was found from a marked decrease in CaCO3 concentration and total diatom count. Mineral and chemical compositions are given for coarse silt fraction of various Late Pleistocene sediments. It is shown that this facial complex is determined by tectonic position of the Guinea Basin.

Results of a Finite-Element Sea-Ice Ocean Model (FESOM) set-up to study the interannual to decadal variability in the deep-water formation rates

The characteristics of a global set-up of the Finite-Element Sea-Ice Ocean Model under forcing of the period 1958-2004 are presented. The model set-up is designed to study the variability in the deep-water mass formation areas and was therefore regionally better resolved in the deep-water formation areas in the Labrador Sea, Greenland Sea, Weddell Sea and Ross Sea. The sea-ice model reproduces realistic sea-ice distributions and variabilities in the sea-ice extent of both hemispheres as well as sea-ice transport that compares well with observational data. Based on a comparison between model and ocean weather ship data in the North Atlantic, we observe that the vertical structure is well captured in areas with a high resolution. In our model set-up, we are able to simulate decadal ocean variability including several salinity anomaly events and corresponding fingerprint in the vertical hydrography. The ocean state of the model set-up features pronounced variability in the Atlantic Meridional Overturning Circulation as well as the associated mixed layer depth pattern in the North Atlantic deep-water formation areas.

(Table 1) Thickness of the Holocene layer and sedimentation rates in the Atlantic Ocean

On the basis of planktonic foraminifera study, thickness of Holocene sediments has been ascertained in 60 sediment cores from various regions of the Atlantic Ocean. Ratios of species reflect warming of the upper water layer at the Pleistocene-Holocene boundary over the entire ocean. The Holocene boundary can be determined not only from microfaunal data, but also from lithologic ones including textural and structural features. Increase in CaCO3 contents in Holocene sediments as compared to Pleistocene is from 5-7% to 60-70% in different parts of the ocean.