Economic and Environmental Geology

Fig. 6.

Fig. 6. Diagrams showing δ¹³C_C2 versus δ¹³D_CH4 (a) and δ¹³C_CH4 (b) of coalbed gases in AA-1 core samples. The coalbed gases of AA-1 core samples (red solid circles) were plotted to non-marine coal-type gas or a mixture of microbial and coal-type gases in the genetic fields (Liu et al., 2019). Coal-type gases in the Bohai Basin samples (blue solid circles) were distinguished from microbial gases in the Qaidam Basin (green solid circles), China (Liu et al., 2019).

Econ. Environ. Geol. 2022;55:261-71 https://doi.org/10.9719/EEG.2022.55.3.261