ESR dating of the sediments of the Last Glaciation at the source area of the Urumqi River, Tian Shan Mountains, China

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• 作者：Yi ; Chaolu ; Jiao ; Keqing ; Liu ; Kexin ; He ; Yuanqing ; Ye ; Yuguang
• 刊名：Quaternary International
• 出版年：2002
• 出版时间：2002
• 年：2002
• 卷：97-98
• 期：Complete
• 页码：141-146
• 全文大小：658 K

文摘

Electron spin resonance (ESR) dates were obtained from glacial quartz sands formed during the Last Glaciation at the source area of the Urumqi River, Tian Shan Mountains, northwestern China. ESR dating of a basal till, interpreted as a subglacial melt-out till deposited in an end moraine which was produced in the late stage of the Last Glaciation, is consistent with ages determined through the AMS ¹⁴C method. However, dating of the overlying sediment, interpreted as supraglacial melt-out till associated with the same moraine, produced a result that differs from that determined using the AMS ¹⁴C method. Subglacial comminution could reset the ESR signal, thus making ESR dating of basal till possible. The Lower Wangfeng Group, formerly of controversial age, was formed ca. 50–70ka, during the early stage of the Last Glaciation. It was deposited throughout the main valley as low as 2300ma.s.l., over a length in excess of 19km. Fluvial sandy gravel was deposited in the interstadial between the early and late stages of the Last Glaciation.