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Three sets of potential source rocks in the Tarim basin, China (modified from Chen et al., 2000).

Triassic- Jurassic continental source rocks--Type III kerogen (humic) with an average TOC of 1.8% to 67%.

Carboniferous –Permian source rocks--Type II and III kerogen with TOC = 0.47% - 5%.

Sinian-Ordovician marine source rocks--Type I kerogen (sapropelite) with TOC = 0.2-3.4%.