School of Energy Resources;
China University of Geosciences;
Beijing 100083;
China;
Chinese Academy of Natural Resources Economics;
Beijing 101149;
China;
Huadian Coal Industry Group Co.;
Ltd.;
Beijing 100035;
China;
Second Oil Production Plant;
PetroChina Changqing Oilfield Company;
Qingyang 745100;
China;
Late Paleozoic; shale; geochemistry; paleoenvironment; eastern Ordos Basin;