1. Institute of Geological Survey; China University of Geosciences; Wuhan 430074 China
2. China Geological Survey, Chengdu Center; Chengdu 610081 China
3. Safety Engineering College, North China Institute of Science & Technology, Langfang; Hebei 065210 China
4. China Geological Survey, Wuhan Center; Wuhan 430205 China
5. School of Earth Sciences; China University of Geosciences; Wuhan 430074 China