Figure 5

Organic petrographical analysis of Da’anzhai member in the study area. (a) 2883.80 m, vitrinite and humic amorphogen; (b) 2896.49 m, vitrinite and humic amorphogen; (c) 2909.55 m, Humic amorphogen; (d) 2941.55 m, vitrinite and humic amorphogen.