Environmental changes during the last glacial in the Eastern Tibetan Plateau revealed by loess sediments in the Aba Basin

Loess deposits are widespread in the Eastern Tibetan Plateau (TP), and act as crucial terrestrial archives for past climate changes and dust activity. Studying their environmental signatures in detail offers valuable evidence to unravel the TP's environmental evolution processes and mechanisms. This study employs quartz optically stimulated luminescence dating to establish a robust chronology for the Gemo loess sequence in the Aba Basin. Utilizing multiple environmental proxies, we reconstructed the environmental change history since ~47 ka in the Aba Basin. Magnetic susceptibility, color index, and carbonate content records suggest a strengthened Indian summer monsoon during the Marine Isotope Stage 3, leading to a relatively humid Tibetan Plateau. The grain size records of the Gemo loess revealed four Heinrich events and Younger Dryas event, indicating the periods of intense dust activity and rapid climate change on the TP during the last glacial period. Comparisons with regional records highlight the significant influence of high-latitude climate system in the Northern Hemisphere on rapid climate change in the TP. Our results suggest that the Atlantic Meridional Overturning Circulation may be the controlling factor of dust activity and climate change in the TP. This study provided crucial evidence for deep understanding of the environmental evolution in TP during the last glacial period.