Middle-Late Pleistocene Glacial Lakes in the Grand Canyon of the Tsangpo River,Tibet

作     者：ZHU Song WU Zhenhan ZHAO Xitao LI Jianping WANG Hua 

作者机构：Chinese Academy of Geological SciencesBeijing 100037China Institute of Geology and GeophysicsChinese Academy of SciencesBering 100029China State Key Laboratory of Earthquake DynamicsInstitute of GeologyChina Earthquake AdministrationBeijing 100029China Institute of Karst GeologyChinese Academy of Geological SciencesGuilin 541004China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2012年第86卷第1期

页      面：266-283页

核心收录：

学科分类：070905[理学-第四纪地质学] 0709[理学-地质学] 07[理学] 08[工学] 

基　　金：supported by Project No.1212011120185 sponsored by China Geological Survey 

主　　题：Zelunglung glacier blocking river dammed lakes Tsangpo River Namjagbarwa 

摘      要：Many moraines formed between Daduka and Chibai in the Tsangpo River valley since Middle Pleistocene. A prominent set of lacustrine and alluvial terraces on the valley margin along both the Tsangpo and Nyang Rivers formed during Quaternary glacial epoch demonstrate lakes were created by damming of the river. Research was conducted on the geological environment, contained sediments, spatial distribution, timing, and formation and destruction of these paleolakes. The lacustrine sediments 14C （10537±268 aBP at Linzhi Brick and Tile Factory, 22510±580 aBP and 13925±204 aBP at Bengga, 21096±1466 aBP at Yusong） and a series of ESR （electron spin resonance） ages at Linzhi town and previous data by other experts, paleolakes persisted for 691±305 kaBP middle Pleistocene ice age, 75-40 kaBP the early stage of last glacier, 27-8 kaBP Last Glacier Maximum （LGM）, existence time of lakes gradually shorten represents glacial scale and dam moraine supply potential gradually cut down, paleolakes and dam scale also gradually diminished. This article calculated the average lacustrine sedimentary rate of Gega paleolake in LGM was 12.5 mm/a, demonstrates Mount Namjagbarwa uplifted strongly at the same time, the sedimentary rate of Gega paleolake is more larger than that of enclosed lakes of plateau inland shows the climatic variation of Mount Namjagbarwa is more larger and plateau margin uplifted more quicker than plateau inland. This article analyzed formation and decay cause about the Zelunglung glacier on the west flank of Mount Namjagbarwa got into the Tsangpo River valley and blocked it for tectonic and climatic factors. There is a site of blocking the valley from Gega to Chibai. This article according to moraines and lacustrine sediments yielded paleolakes scale： the lowest lake base altitude 2850 m, the highest lake surface altitude 3585 m, 3240 m and 3180 m, area 2885 km2, 820 km2 and 810 km2, lake maximum depth of 735 m, 390 m and 330 m. We disclose the reason that previous expe