Recent changes of biogenic carbonate deposition in anoxic sediments of the Black Sea: sedimentary record and climatic implication

Recent changes of carbonate deposition were traced in a Black Sea sediment core taken in the western abyssal basin. The sediments were dated from a vertical profile of excess 210Pb. The 210Pb geochronology corresponded well to the 137Cs fallout record. A 20-year cyclic variability of carbon deposition has been traced in the dated sediments and has been related inversely to the long-term changes in temperature of air over the basin, forcing the convection in the upper water column, which may bear influence upon the coccolithophorid blooms by bringing nutrients from deeper water to the surface.