Hydrocarbon generated from Middle-Lower Jurassic coal beds as the main source rock in the basin has remarkably high Pr/ph ratio as well as heavy carbon isotope and C29 sterane.

• 中、下侏罗统煤系地层是主要的烃源岩，这套源岩生成的油气具有显著的姥鲛烷优势、重碳同位素以及富含C29甾烷等特征。