Affiliation: | Institute for Rock Magnetism, Department of Geology and Geophysics, University of Minnesota, 55455,;USA. E-mail: Center for Arid Environment and Paleoclimate Research, Department of Geography, University of Lanzhou, Lanzhou, Gansu, China 730000; Paleomagnetism Lab, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China 100101 |