Physical condition favoring formation of marine hydrocarbon source rocks

Both tremendous productivity and anoxic condition favor formation of marine hydrocarbon source rocks. The anoxic condition could be realized in the marginal seas by a physical process-water mass delamination. For example, differences in salinity and temperature separated water mass into two layers in the Red Sea. Such a case might occur also in the Paleozoic South China. The anoxic condition in the deep layer is favorable for accumulation of marine hydrocarbon source rocks.