Fig. 12

A: Cross-graphs of TOC vs. δ13Corg show the type of hydrocarbon-generating organisms of the Wulalike Formation. B: Cross plots of TOC vs. Siexcess of the black shale of the Wulalike Formation show the relationship between paleoproductivity. C, D, E, F: Cross-plots between Corg/P, VEF, UEF, and MoEF exhibit their different geochemical behavior in a redox environment. G, H, I: The cross-plots of VEF, MoEF, and UEF versus TOC show the relationship between enrichment factors and organic matter accumulation.