1. School of Earth Science & Key Laboratory of Mineral Resources in Western China (Gansu Province), Lanzhou University, Lanzhou, China
2. Geological Survey of Gansu Province, Gansu Geological Survey Institute, Lanzhou, China
3. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China
4. College of Earth and Environment Sciences, Lanzhou University, Lanzhou, China