ESR dating of glacial tills and glaciations in the Urumqi River headwaters, Tianshan Mountains, China

Electron spin resonance (ESR) dating of the Shangwangfeng, the Xiawangfeng, and the Gaowangfeng tills in the headwaters of the Urumqi River was carried out using Ge centers in quartz grains. The Shangwangfeng till is dated at 35±3.5 ka BP. Three dates from the lower portion of the Xiawangfeng till are 171.1±17, 176±18, and 184.7±18 ka BP, respectively, and the age of the Gaowangfeng till is 459.7±46 ka BP. Considering the available ages (i.e. 14C, TL and ESR) and the principles of geomorphology and stratigraphy, the Shangwangfeng till is determined to be deposited in marine isotopic stage 2–3 (MIS2–3). The upper part of the Xiawangfeng till was formed in MIS4 and the lower part was deposited in MIS6. The Gaowangfang till is the oldest at the head of the Urumqi River, corresponding to MIS12. The age of the Gaowangfang till also demonstrates that the Tianshan Mountains lay at a suitable altitude for a glacial climate at that time, when the glaciers on this segment of the mountain began to develop.