1. School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu Province 210023, China
2. Department of Earth, Environmental and Geographic Sciences, The University of British Columbia, Okanagan, 3247 University Way, Kelowna, BC, Canada, V1V 1V7
3. Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada