Key Laboratory of Shale Gas and Geoengineering Institute of Geology and Geophysics Chinese Academy of Sciences Chaoyang District Beijing 100029 China;
Institute of Earth Science Chinese Academy of Sciences Beijing 100029 China;
University of Chinese Academy of Sciences Beijing 100049 China;
Arba Minch University Department of Geology P.O.Box 21 Arba Minch 00251 Ethiopia;
