Gas-Geochemical Studies of Surface Sediments of the South Tatar Sedimentary Basin (Sea of Japan)

The paper reports the results of gas-geochemical and lithochemical studies of the modern bottom sediments sampled in the South Tatar sedimentary basin (Sea of Japan) during a comprehensive geological and geophysical expedition on the R/V Akademik Oparin (OP-54). Anomalies of hydrocarbon gases (HCGs) and chemical elements in the surface bottom sediments were estimated. The hydrocarbon-bearing sediments are mainly represented by aleuritic varieties with psammitic (up to 46%) and pelitic (up to 43%) components. The maximum contents of Si, Ti, K, Ca, Sr, Zr, and Y are noted in the bottom sediments of coastal shelf zones; the concentrations of S, Ni, Cu, Zn, Pb, V, Fe, Mn, Rb increase in the shelf–bathyal direction. Sediments with anomalous methane contents are significantly enriched in S, Mn, V, Cu, Ni, Zn, and Pb. The data obtained make it possible to suggest the presence of sources of hydrocarbon migration and to consider further the prospects of detailed works for the assessment of the oil, gas and gas hydrate potential in the southern part of the Tatar Strait. The research corresponds to the tasks of the working group “Gas hydrates and methane flows in the Indo-Pacific region” of the WESTPAC subcommittee of the Intergovernmental Oceanographic Commission of UNESCO.