1. a Chinese Academy of Geological Sciences , Beijing , 100037 , PR China
2. b The Shengli Oil Company , Dongying , 257100 , PR China
3. c School of Earth and Space Sciences, University of Science and Technology of China , Hafei , 230026 , PR China
4. d Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou , 510640 , PR China
5. e Institute of Geology and Geophysics, Chinese Academy of Sciences , Beijing , 100029 , PR , China