Grain Size Distribution, Organic Carbon and Geochemical Markers in the Surface Layer of Bottom Sediments in the Northeastern Part of the Kara Sea

The upper layer of bottom sediments in the northeastern part of the Kara Sea is studied. It is shown that the composition of sediments is dominated by silt, the proportion of sand increases towards the shore. The content of organic carbon (average value — 1.1% wt.) is close to the average content in sediments of the Kara Sea, increasing at deep-sea stations. The revealed linear relationship between the content of organic carbon and the surface area of sediment shows that sorption on the particles surface is the predominant accumulation form of organic matter (OM) in sediments. The average n-alkanes concentration in the analysed samples is 1.1 μg/g of sediment, the distribution spectrum is dominated by terrigenous origin odd high-molecular homologues.