西藏阿里札达盆地地质构造的基本特征及其演化  

The basic characteristics and evolution of the geological structures in the Zhada basin,Ali,Tibet

作　　者：孟宪刚[1] 朱大岗[1] 邵兆刚[1] 杨朝斌[2] 韩建恩[1] 余佳[1] 孟庆伟[1] 吕荣平[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]西藏自治区国土资源厅

出　　处：《地学前缘》2006年第4期160-167,共8页Earth Science Frontiers

基　　金：国家自然科学基金资助项目(40572134);中国地质调查局资助项目"青藏高原第三纪重点古湖泊环境演变序列"(1212010511902)

摘　　要：通过对札达盆地及其周缘的野外地质调查和地层剖面的实测,确定了札达盆地的大地构造位置以及在喜马拉雅板块构造格局中的位置,并从基底构造、盆缘构造和盆内构造三个方面,论述了札达盆地的地质构造特征。从盆地类型、盆地的形成过程,对札达盆地的构造成因进行了探讨。尤其是札达盆地上新世—早更新世河湖相沉积中香孜组与古格组、古格组与托林组之间两个不整合面的发现,象泉运动与古格运动两次构造运动的确定,以及上新统褶皱的发现,为研究青藏高原喜马拉雅运动晚阶段(第Ⅲ幕)的表现形式及新近纪到第四纪时期高原隆升过程、方式等,提供了实际资料和重要依据。Through field geological investigation, comprehensive analysis of earlier studies and the study of measured stratigraphic sections in the Zanda basin, we have determined the position of the basin in the tectonic framework of the Himalayan plate. The Zanda basin is located in the southwestern Qinghai-Tibet plateau, in an impor- tant geotectonic setting. The major tectonic trends are NW-SE, having formed during Indian-Eurasian plate continental convergence and underthrusting. The NW-SE deformation can be divided into early and late stages, which developed the basic tectonic framework of the Zanda basin. The Zanda basin is a hinterland basin of Himalayas. It developed in proximity to the Yarlung Zangbo river suture zone and the Himalayas fold belt on the north side of the Himalayas and above the north-dipping A-type subduction zone of the Siwaliks fault block orogenic belt. We address the characteristics of the Zanda basin structures through the study of basement, basin-periphery and intrabasin structures; and we discuss the tectonic origin of the basin. The authors believe that the Zanda basin is a ＂seesaw type＂ dustpan fault basin. According to measured sections, major unconformities in fluvio-lacustrine sediments of the Pliocene-early Pleistocene Zanda basin between the Xiangzi and Guge groups, and the Guge and Tuolin groups, define the Xiangquan and Guge tectonic movements, respectively. Our research provides important information and evidence for the nature of the late episode （third phase） of the Himalayan movement, and the Neogene to Quaternary uplifting process of the plateau.

关 键 词：西藏札达 上新世-早更新世 地质构造组合 构造演化 

分 类 号：P548[天文地球—构造地质学]