Determination of the age of lake terraces, the last glacial advance, and rates of normal faulting in the Tangra Yum Co graben using 10Be exposure and optically stimulated luminescence dating

使用 10Be 曝光和光激发光测年法确定 Tangra Yum Co 海沟中湖泊阶地的年龄、末次冰川推进和正常断层的速率

基本信息

批准号：
202886354
负责人：
Professor Dr. Manfred Anton Frechen
金额：
--
依托单位：
Leibniz-Institut für Angewandte Geophysik (LIAG)
依托单位国家：
德国
项目类别：
Priority Programmes
财政年份：
2011
资助国家：
德国
起止时间：
2010-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/202886354?language=en
关键词：
Determination age lake terraces last

项目摘要

Terraces and benches around many lakes on the Tibetan Plateau record significant changes in water level and document pronounced variations in past climatic and environmental conditions. We propose to date a sequence of paleo-shorelines at Tangra Yum Co – a deep lake situated in an active graben system in southern Tibet – with in situ-produced cosmogenic 10Be and luminescence dating. Wellpreserved lake terraces extend to a height of about 200 m above the present water level of Tangra Yum Co, however, it is unknown whether the related lake level highstands occurred during the early Holocene climate optimum, in the course of the last deglaciation, or are even older. In addition to dating lake terraces and benches, we will constrain the age of the last glacial advance by 10Be dating of granitic boulders from moraines. Finally, we aim to derive slip rates for major normal faults at the margin of the lake. The latter will be achieved by combining topographic surveying of fault scarps, dating of displaced surfaces, paleoseismologic investigations of fault exposed in gullies, and determination of catchment-wide erosion rates in the footwalls of the faults. The planned research will unravel the relationship between lake-level variations, changes in climate, and normal faulting, and – combined with the results of the other TiP groups – resolve the impact of these processes on the subsidence and sedimentation patterns in an active graben system typical for southern Tibet.

藏族高原上许多湖泊周围的露台和长凳都记录了水位的显着变化，并记录了过去的气候和环境条件下的明显变化。我们建议在Tangra Yum Co（一个位于西藏南部活跃的Graben系统中的深湖）上约会一系列古毛线，并具有原位生产的宇宙基因10BE和发光约会。保存良好的湖泊露台延伸至坦拉（Tangra Yum Co）目前的水位高约200 m的高度，但是，未知相关的湖泊高台是否发生在早期全新世气候最佳期间，在最后一次脱水过程中，甚至更老。除了约会湖泊露台和长凳外，我们还将以10be的大巨石来限制上一次冰川前进的年龄。最后，我们的目标是在湖泊边缘得出主要正常断层的滑动速率。后者将通过结合断层陡坡的地形测量，流离失所的表面约会，对沟渠中暴露的断层的古介质研究以及确定断层足球中流域范围内的侵蚀率的确定。计划的研究将揭示湖泊水平的变化，气候变化和正常断层之间的关系，并与其他尖端组的结果结合在一起 - 解决这些过程对南部典型的活跃的抓取系统中的沉降和沉降模式的影响。