Evaluation of Favorable Shale Gas Intervals in Dawuba Formation of Ziyun Area, South Qian Depression

Figure 9

The resolution comparison of reducing environment exquisite changes for variety of parameters: (a) cross plot of Ce/La values and depth for the four member shale samples; (b) cross plot of Cr/Cu values and depth for the four member shale samples; (c) cross plot of Th/U values and depth for the four member shale samples; (d) cross plot of V/Sc values and depth for the four member shale samples.

(a)

(b)

(c)

(d)