Quaternary glacial history of the Paleo-Daocheng ice cap (southeast Tibetan Plateau) reconstructed from in situ cosmogenic 10Be ages

Abstract

Quaternary climate change on the Tibetan Plateau is vital for understanding environmental evolution both globally and in the Northern Hemisphere. The Paleo-Daocheng Ice Cap (PDIC), located on the southeastern Tibetan Plateau (TP), plays a crucial role in exploring the coupling mechanism between TP uplift and climate change. This study sampled granules, pebbles, boulders, and coarse-grained sand from the surfaces of moraines and bedrock samples in the PDIC area. The new ¹⁰Be exposure ages of 23 samples from three different glacial remnants of the PDIC ranged from 71.0 ± 4.6 to 15.6 ± 1.0 ka. Subsequently, a comprehensive analysis of both new and previously-compiled ¹⁰Be ages from the Shaluli Mountains was conducted. This analysis confirmed that the area entered the cryosphere around 0.8–0.6 Ma. Probabilistic cosmogenic age analysis tool (P-CAAT) analysis on the ¹⁰Be ages since Marine Isotope Stage (MIS) 6 was also conducted. This identified at least four significant glacial fluctuations (at 153.5 ± 17.6 ka, 109.7 ± 18.6 ka, 54.0 ± 14.4 ka, and 19.4 ± 9.2 ka). These glacial fluctuations represent a comprehensive response to temperature, precipitation, and insolation, with these climate determinants making varying contributions across different stages since MIS 6.