喜马拉雅山脉东段空布岗峰东麓的第四纪冰川作用序列及其初步的年代学约束  

Late Quaternary Glaciation Successions and Their Dating on the Eastern Piedmont of Kongbugang Peak in the Eastern Himalayas

作　　者：吴中海[1] 张永双[1] 赵希涛[2] 马志邦[2] 叶培盛[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《冰川冻土》2008年第5期807-813,共7页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(40501006);中国地质科学院地质力学研究所基本科研业务费项目(DZLXJK200706);科技部国际合作项目(2006DFA21320);中国地质调查局“滇藏铁路沿线地壳稳定性调查评价”项目(1212010541404)资助

摘　　要：野外调查表明，喜马拉雅山脉东段的空布岗峰东麓晚第四纪期间至少发育了4套冰碛物．初步的U系和热释光（TL）测年结果表明，该区最早的冰川作用出现在MIS6（深海氧同位素阶段）之前，并可能是该区规模最大的一次冰川作用过程．最近一次显著的冰川作用出现在倒数第二次冰期，其时代约为160．9～109．0kaBP或略早，大致对应MIS6，其中至少包含了两个阶段．最近的两次冰川作用分别发生于末次冰期和全新世期间，其中包含了多个次一级的冰川波动．Glacial successions on the eastern piedmont of Kongbugang Peak in the eastern Himala yong Co graben to east, are reassessed and preliminary glacial chronologies are presented for the region. Based on field investigation to the associated glacial landforms and detailed analysis on remote images, the glacial landforms are divided into four sets of tillscorresponding with so-called Nyanyxungla Ice Age, Jilongshi Ice Age, Ronbushi Ice Age and Holocene glaciations, respectively, from oldest to youngest in the area in the light of morphostratigraphy and relative weathering. The oldestGlacial Stage （orthe first tills）is represented by subdued and rounded moraine ridgesor platforms that contain boulders commonly exceeding several meters in diameter. These usually occur on high surfaces （about 4 900-5 000 m a. s. 1. ） above the main valleys and often are best seen on the interfluves between the lateral moraines of the second tills along the eastern piedmont of Kongbugang Peak, and deeply weathered on thetop of moraines platform. Becausethe tills have been dissected and partly overlaid by younger moraines, the reserved parts of the oldest tills are very limited in region, but it is believedthat the Glaciation maybe the largest in extentin light of evidence for piedmont glaciers, whichfill the whole Cona-Nariyong Co basin and joint with the glaciersfrom eastern mountains of the Cona-Nariyong Co basin. The second tills arerepresented by a few end moraines extendinginto Cona-Nariyong Co basin at an altitude about 4 800 m a. s. lin north of the basin, and some hummock moraines of piedmont glaciers at an altitude about 4 700-4 600 m a. s. 1 in the central basin. They extend to 10-11 km far from the present ridge of Kongbugang Peak and represent the last most prominent glaciation in the region. The boulders on these moraines are generally 1-3 m in diameter; they are limitedly weathered on surface. The tills may be divided into two sets of moraines on basis of the weathering and end moraines landform around Yab

关 键 词：西藏 喜马拉稚山脉 错那-拿日雍错地堑 第四纪 冰川作用 MIS6 

分 类 号：P534.63[天文地球—第四纪地质学]