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

Figure 3

(a) Plot of δ¹³C-C₂H₆ versus δ¹³C-CH₄; (b) relationship between δ¹³C-CO₂ and CO₂ content of gases in different gas fields of the Ordos Basin (modified from [33]). Note: symbols for samples from different areas of the Ordos Basin are used in all subsequent figures.

(a)

(b)