天山木扎尔特河流域的冰川地貌与冰期  

Glacial Geomorphology and Glaciations in the Muzhaerte River Valley,Tianshan Mountains

作　　者：赵井东[1] 王杰[2] 刘时银[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室,兰州730000 [2]兰州大学西部环境教育部重点实验室,兰州730000

出　　处：《地理学报》2009年第5期553-562,共10页Acta Geographica Sinica

基　　金：中国科学院知识创新工程重要方向性项目(KZCX2-YW-301);国家自然科学基金项目(40501007);国家重点基础研究发展计划项目(2007CB411500);科技部科技基础性工作专项项目(2006FY110200)~~

摘　　要：木扎尔特河流域位于天山最大现代冰川作用中心托木尔峰的东南坡,在第四纪冰期与间冰期气候旋回中,河谷与山麓带留下了4套形态清晰的冰川沉积。冰碛地形包含着丰富的古环境变化信息,对它们进行研究有助于认识该流域的冰川演化与重建该地区的古环境。应用ESR测年技术,选用石英颗粒中对光照与研磨较敏感的Ge心作为测年信号,对该流域的第三套破城子多列终碛垅及其冰水沉积,第四套克孜布拉克冰碛剥蚀平原上覆河流相砾石沉积以及一出露完整的沉积剖面进行测年。结合地貌地层学原理以及其他古环境研究资料进行综合分析可得出:河谷中第一套3～4列终碛垅形成于小冰期;第二套高大的吐盖别里齐终碛垅为新冰期冰进产物;破城子终碛垅沉积于MIS2～4;克孜布拉克冰碛形成于MIS6。破城子终碛垅地形及测年结果表明末次冰期冰川作用过程中该处至少存在3次大的冰进,可分别对应于MIS4、MIS3b与MIS2。MIS2与MIS3b时冰川为复合山谷冰川,MIS4与MIS6时为山麓冰川。末次冰期冰川作用过程中,古木扎尔特冰川长约92～99km,克孜布拉克冰期最盛时的古木扎尔特冰川长约120km。The Muzhaerte River Valley is located on the southeastern slope of the Tumur Peak, the largest center of modern glaciation in the Tianshan Mountains of China. Four sets of moraines are well-preserved in the valley and on the piedmont. The landforms contain vital information about the variation of the palaeo-environment, and studies on them make it easy to understand the change of ancient glaciers and to reconstruct the palaeo-environment in this region. Electron spin resonance （ESR） dating of a well-exposed section, end moraines and associated outwashes, fluvial sediments on the Kezibulake moraines were carried out using Ge centers in quartz grains, which are sensitive to the sunlight and grinding. Considering the principles of geomorphology and stratigraphy and the available data of the palaeo-environment, some conclusions can be drawn as follows： the first set of moraines, consisting of 3-4 end moraines, were deposited in Little Ice Age; the Tugaibieliqi end moraine was the sediment of the Neo-glacial; the Pochengzi end moraines and the Kezibulake moraines were determined to deposit in the last glaciation and in MIS6. The Pochengzi end moraines and their dates demonstrate that at least three large glacial advances occurred during the last glaciation, corresponding to MIS4, MIS3b and MIS2, respectively. Furthermore the result shows that the glaciers were compound valley ones in MIS2 and MIS3b, while they were piedmont ones in MIS4 and MIS6. The length of the ancient Muzhaerte glacier was about 92-99 km during the Pochengzi glaciation and about 120 km during the Kezibulake glaciation.

关 键 词：冰川地貌 ESR测年 海洋氧同位素阶段(MIS) 木扎尔特河流域 天山 

分 类 号：P343.6[天文地球—水文科学]