1. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
2. School of Earth Resources, China University of Geosciences, Wuhan 430074, China
3. School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China
4. Department of Earth Sciences, University of Adelaide, Adelaide, SA 5005, Australia
5. Geological Survey Institute of Inner Mongolia Autonomous Region, Hohhot 010020, China
6. School of Earth Science, East China University of Technology, Nanchang 330013, China