Funding for this research was provided by:
Strategic Priority Research Program of the Chinese Academy of Sciences (XDB26000000)
National Natural Science Foundation of China (41602021)
Key Research Program of the Institute of Geology & Geophysics, CAS Grant (IGGCAS-201905)
National Social Science Foundation of China (19BKG009)
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment (SKLLQGZR2002)
Article History
Received: 16 February 2020
Accepted: 14 April 2020
First Online: 8 May 2020