Origin of hydrocarbons in holocene sediments of the Nordik Seas and Barents Sea

The concentrations and composition of hydrocarbons (aliphatic – AHCs and polycyclic aromatic hydrocarbons – PAHs) were determined using molecular markers in Holocene sediments of the Nordik Seas and the Barents Sea (cruise 84 of the R/V Akademik Mstislav Keldysh, 2021). A wide range of concentrations in surface bottom sediments has been established: Corg (0.25–2.71%), AHCs (7–182 μg/g) and PAHs (0–1918 ng/g). The distribution of hydrocarbons is determined mainly by the processes occurring in the sedimentary strata (changes in Eh and fluid flows), and to a lesser extent by the lithotype of sediments. At the same time, the formation of autochthonous homologues is observed in the composition of alkanes, and in the composition of PAHs – naphthalenes.