Xie, Hao ， Liu, Caicai ， Zhang, Huiping ， Zhang, Zhuqi ， Xu, Hongyan ， Wei, Xiaotong
2024-09-15 PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 2024 650(卷), null(期), (null页)
The Qinghai Lake is located near the junction of the East Asian summer monsoon (EASM), East Asian winter monsoon (EAWM), and Westerlies. The aeolian deposits around Qinghai Lake hold significant value in tracking the paleowind direction, which is crucial to reconstruct paleo-atmospheric circulations. In this paper, a systematic study of anisotropy of magnetic susceptibility (AMS), rock and environmental magnetism, grain size distribution, and X-ray diffraction was conducted on a loess sequence (named Heimahe) in the Qinghai Lake area. The AMS results of the Heimahe section reveal two prevailing winds of NE-SW and NW-SE orientations during the last deglacial in the Qinghai Lake area. Grain size distribution and mineral composition analyses suggest that the NE-SW and NW-SE winds are respectively associated with the winter monsoon and the Westerlies. Moreover, the variations in magnetic lineation as well as other AMS parameters indicate that the dominant paleowind direction in the Qinghai Lake region during the last deglacial changed periodically with a similar to 300 yr frequency. It appears that magnetic fabric is capable of recording rapid changes in paleowind direction.