Extensive glaciations between MIS 8 and MIS 5 on the eastern side of the Guliya ice cap, West Kunlun Mountains

Abstract

Glacial chronology is critical to the reconstruction of former glaciers. The West Kunlun Mountains represent one of the most important areas for understanding the response of glacier to climate change in regions dominated by the Westerlies. However, accurate chronologies for Quaternary glaciations in this area are still lack. In this work, we identified two sets of moraines at the eastern side of the Guliya ice cap in the West Kunlun Mountains and constrained their emplacement times using the cosmogenic 10Be exposure dating method. The outer moraine set, within ~6 km in front of the modern glaciers, was dated to 231.8 ± 14.7 ka ago, and the inner moraine set, within ~3.5 km downstream of the modern glaciers, was dated to 113.7 ± 7.0 ka ago. This suggested that two glacier advances could have occurred during the marine isotope stages (MIS) 8–7 and MIS 6–5, respectively, and the glaciers became progressively less extensive between these two glacial periods at the eastern side of the Guliya ice cap. Comparing our dating results with previous studies in the Gurla Mandhata, the Tashkurgan Valley, the Muztag Ata and Kongur Shan, we concluded that regional aridification was the most likely explanation for the progressively less extent of the two glacier advances in the western Tibetan Plateau regions.