Aeolian activities history since 20.8 ka recorded by aeolian sediment in the southwestern Junggar Basin

The loess deposits in Xinjiang play a crucial role in the dust deposition system of Asia, offering significant insights into the climate change in Central Asia arid regions. While previous studies have mainly focused on precipitation changes, research on the aeolian activity during the Late Quaternary remains relatively scarce, and this scarcity restricts a comprehensive understanding of the interaction between surface processes and climate changes. To fill this research gap, this study selected a 340 cm long loess-aeolian sand sequence (WS22, 44°59'18.96″N, 84°14'24.27″E) from the Aibi Lake basin in the southwestern Junggar Basin. We established a chronological framework over the past 20.8 ka using K-feldspar pIRIR dating, additionally, grain size end-member analysis was conducted to reconstruct the history of aeolian activity in the region over the past 20.8 ka. The results demonstrated that during the period of 20.8~16.5 ka, the study area experienced an extremely arid climate, characterized by intense regional dust storm activity; from 16.5 ka to 8.0 ka, aeolian activity remained relatively strong, with significant local sandstorms occurring during the periods of 16.5~14.8 ka and 12.8~11.2 ka, these enhanced sandstorm activities likely correspond to the cold events known as Heinrich 1(H1) and Younger Dryas (YD), in addition, a minor phase of enhanced local sand input was detected during 9.2~8.2 ka, which was likely driven by the 8.2 ka cold event; since 8.0 ka, as precipitation in the westerlies zone gradually increased and vegetation coverage expanded, regional dust storm activity has gradually diminished, this decrease in aeolian activity reflects the overall climate amelioration in the region. This study demonstrates that the aeolian activity was not solely driven by precipitation variability associated with the westerlies, it was also modulated by near-surface wind conditions, which are influenced by the Siberian high pressure system, additionally, local factors such as sand source availability and topography played significant roles in shaping the intensity and pattern of aeolian activity. The findings of this study provide valuable insights into the historical patterns of aeolian activity in Central Asia, contributing to a deeper understanding of past climate variability and its effects on the environment.