Carbon and Hydrogen Isotopic Reversals in Highly Mature Coal-Derived Gases: A Case Study of Paleozoic Gases in the Southern Ordos Basin, China

Figure 5

Carbon isotopic series of alkane gases in (a) Yan’an and upper Paleozoic South Jingbian gas fields; (b) lower Paleozoic South Jingbian field; (c) southern Sulige field; and (d) Daniudi, northern Sulige, and Shenmu gas fields.

(a)

(b)

(c)

(d)