Favorable lithofacies types and genesis of marine-continental transitional black shale: A case study of Permian Shanxi Formation in the eastern margin of Ordos Basin, NW China

WU Jin,WANG Hongyan,SHI Zhensheng,WANG Qi,ZHAO Qun,DONG Dazhong,LI Shuxin,LIU Dexun,SUN Shasha,QIU Zhen

Fig. 3. Core samples of typical shale lithofacies of the Permian Shanxi Formation in the eastern margin of the Ordos Basin. (a) C-L: dark-gray massive silty shale with coal clasts and rip-up clasts, Well Daji51 2280.00 m; (b) C-L: dark-gray silty shale with fossilized plant stems and leaves, Well Daji51, 2268.93 m; (c) S-L: gray massive silty shale, showing bioturbation in the upper part and featuring mud gravel development, Well Daji51, 2288.82 m; (d) S-L: dark-gray shale with horizontal texture, Well Daji51, 2290.65 m; (e) S-M: dark-gray shale with horizontal texture, Well Daji51, 2292.59 m; (f) S-M: grayish-black shale, Well Daji51, 2296.33 m; (g) M-M: grayish-black calcareous shale, Well Daji51, 2298.50 m; (h) S-H: blackish-gray dolomitic shale, Well Daji51, 2297.67 m; (i) C-H: blackish-gray carbonaceous shale, Well Daji51, 2270.87 m.