Definition and abundance threshold of marine source rocks developed in South China

Because the marine strata in South China has complex tectonic setting and the hydrocarbon generating process for some old source rocks, as Cambrian shale, is too early, an additional definition on marine effective source rock suggested that the source rock must have contributed to the present traps or the late reservoir formation. It is proposed that the time limitation and associated index should be added to the evaluation of old source rocks. The sedimentary environment controlled the development of carbonate source rock and the algae carbonate is uppermost source rocks in carbonates. For effective source rocks with variable maturity,the threshold of organic carbon content should be different.