1. Chengdu Institute of Geology and Mineral Resources, Chinese Geological Survey, Chengdu 610081, PR China
2. School of Earth Sciences, Gansu Key Laboratory of Mineral Resources in Western China, Lanzhou University, Lanzhou 730000, PR China
3. State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210046, PR China