1. Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education, China University of Mining and Technology, Xuzhou, China
2. School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, China
3. Hubei Key Laboratory of Resources and Eco-Environment Geology, Hubei Geological Bureau, Wuhan, China
4. Department of geology, Northwest University, Xi’an, China
5. Ningxia Mineral and Geological Survey Institute (Autonomous Region Institute of Mineral Geology), Yinchuan, China
6. Division of Urban Construction and Transport Engineering, PowerChina Northwest Engineering Corporation Limited, Xi’an, China