State Key Laboratory of Continental Dynamics/Department of Geology;
Northwest University;
Xi'an 710069;
Shaanxi;
China;
School of Earth and Environment;
University of Leeds;
Leeds LS2 9JT;
U.K;
Gansu Coal Geological Research Institute;
Lanzhou 730000;
Gansu;
China;
Key Laboratory of Petroleum Resources Research;
Institute of Geology and Geophysics;
Chinese Academy of Sciences;
Lanzhou 730000;
Gansu;
China;
Institute of Geochemistry;
Chinese Academy of Sciences;
Guiyang 550002;
Guizhou;
China;