Holocene accumulation of organic carbon at the Laptev Sea continental margin (Arctic Ocean): sources, pathways, and sinks

Composition and accumulation rates of organic carbon in Holocene sediments provided data to calculate an organic carbon budget for the Laptev Sea cont inental margin. Mean Holocene accumulation rates in the inner Laptev Sea va ry between 0.14 and 2.7 g C cm(-2) ky(-1): maximum values occur close to th e Lena River delta. Seawards. the mean accumulation rates decrease from 0.4 3 to 0.02 g C cm(-2) ky(-1). The organic matter is predominantly of terrige nous origin. About 0.9 x 10(6) t year(-1) of organic carbon are buried in t he Laptev Sea, and 0.25 x 10(6) t year(-1) on the continental slope. Betwee n about 8.5 and 9 ka, major changes in supply of terrigenous and marine org anic carbon occur, related to changes in coastal erosion, Siberian river di scharge, and/or Atlantic water inflow along the Eurasian continental margin .