稻城古冰帽末次冰期冰川年代学研究—以查牙拉冰碛垄为例

项目名称： 稻城古冰帽末次冰期冰川年代学研究—以查牙拉冰碛垄为例

项目编号： No.41503054

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 张志刚

作者单位： 南京师范大学

项目金额： 22万元

中文摘要： 青藏高原地区第四纪气候变化研究是理解北半球乃至全球尺度上环境变化的关键，古冰川事件是第四纪时期气候波动最直接、最有力的地质证据，而如何准确测定冰川遗迹的形成年代是目前第四纪冰川研究的重点。目前，宇生核素暴露测年和光释光测年技术被广泛应用在冰川地貌的年代测定并取得了一些可靠的结果。位于青藏高原东南部的稻城古冰帽，第四纪曾多次发生冰川大规模作用，保留了大量的古冰川地貌为宇生核素暴露测年和光释光测年研究提供了天然实验室。尽管该区已有大量研究，然而关于末次冰期冰川作用历史还存在一些争论。本项目拟在前人研究的基础上，综合应用地貌地层法、宇生核素Be-10、Al-26暴露测年和光释光测年技术测定冰帽中部查牙拉系列冰碛垄的形成年代，以此重建稻城古冰帽末次冰期间冰川演化历史。该研究对进一步认识稻城古冰帽的演变历史以及冰川地貌年代测定，将是一项具有突破意义的工作。

中文关键词： 原地宇生核素；暴露测年；光释光；冰期划分；青藏高原

英文摘要： The glacial landforms of the Qinghai-Tibetan Plateau (QTP) provide a unique opportunity to research hemispheric and global environmental changes. The Quaternary glaciations are the most direct and convincing evidence of climate fluctuations. An accurate chronology of these palaeo-glaciations on the QTP is highly demanded. At present, the TCN (in situ terrestrial cosmogenic nuclides) exposure dating and OSL (optically stimulated luminescence) methods are widely used to date glacial landforms. Meanwhile, some reliable results are obtained. The temperate p-DIC (palaeo-Daocheng Ice Cap), located in the southeastern QTP, is sensitive to climate change. There was a repeatedly formed ancient ice cap during the Quaternary and left special glacial erosional-depositional landforms. The well-preserved glacial remnants provide a natural laboratory for developing the TCN and OSL methods in the field of dating glacial landforms. Although there has been a lot of work in this area, consensus has not reached on the history of glacier advance during last glaciations. Based on the previous research, we intend to determine the moraines chronology in the Chayala which lie in the center of p-DIC area by using morphostratigraphy, TCN Be-10 , Al-26 exposure dating and OSL methods, so that can reconstruct the history of p-DIC during last glaciations. The research will be a breakthrough for further understanding the evolution history of the p-DIC and glacial geomorphology dating.

英文关键词： in situ cosmogenic nuclides;surface exposure dating;optically stimulated luminescence;glacial periods;Tibetan Plateau