A find of an authigenic methane-derived carbonate in the Chukchi Sea

This report presents data on the chemical, mineral, and isotope composition (δ13C and δ18O) of a large-sized fragment of limestone from the norhteastern part of the Chukchi Sea. It was shown that the formation of the rock is related to the authigenic microbial oxidation of methane. This process is of interest in view of the potential presence of oil and gas in the sedimentary deposits of the northern seas of Russia.