THE PATTERN OF δ13CORG VERSUS HI/OI RELATION IN RECENT SEDIMENTS AS AN INDICATOR OF GEOCHEMICAL REGIME IN MARINE BASINS: COMPARISON OF THE BLACK SEA, KARA SEA, AND CARIACO TRENCH

Abstract

An approach is suggested to evaluate the geochemical regime of marine basins. By comparative study of the carbon isotopic composition of organic matter and its hydrogen index to oxygen index ratio in recent sediments a significant role of chemosynthetic bioproduction in the Black Sea, and extensive oxidative diagenesis of the organic matter in the Kara Sea have been demonstrated. The relative role of chemosynthetic production in the Cariaco Trench seems to be different compared to that in the Black Sea.