ORGANIC-CARBON ACCUMULATION IN THE HOLOCENE SAPROPEL OF THE BLACK-SEA

The modern laminated coccolith marl (unit 1) of the Black Sea containi ng 2-6 wt% organic carbon overlies a finely laminated sapropel (unit 2 ) containing 5-20 wt% organic carbon. However, the accumulation rate o f organic carbon in the sapropel is not significantly different from t hat in unit 1, In contrast, the accumulation rates of either CaCO3 or lithogenous matter (clay) are significantly lower in the sapropel comp ared with unit 1, Thus, the sapropel has very high organic carbon cont ents because of lesser dilution of the organic fraction by the other b ulk components. Because the accumulation rate of organic carbon in the sapropel is similar to that in unit 1, which is not significantly dif ferent from accumulation rates in oxygenated environments in similar s ettings, the Black Sea sapropel is not necessarily characteristic of a noxic basins.