阿尔金断裂中段新生代隆升过程研究进展  

Research Progress of the Cenozoic Uplift Process in the Middle Part of Altyn Tagh Fault

作　　者：张益银 郭佩[1,2] 徐崇凯 李被 ZHANG Yi-yin, GUO Pei, XU Chong-kai, LI Bei(a. State Key Laboratory- of Continental Dynamics, b. Department of Geology-, Northwest University, Xi＇ an 710069)

机构地区：[1]西北大学大陆动力学国家重点实验室,西安710069 [2]西北大学地质学系,西安710069

出　　处：《西安文理学院学报（自然科学版）》2018年第4期99-105,共7页Journal of Xi’an University(Natural Science Edition)

摘　　要：阿尔金断裂以其典型的左行走滑形迹令世人瞩目,其活动过程分析对青藏高原隆升机制研究具有重要意义.通过总结、归纳前人在该区的热年代学研究成果,并结合柴达木盆地构造、沉积特征,对阿尔金断裂中段的隆升过程作了系统的探讨.阿尔金断裂在中生代就曾活动过,随后进入较长的休眠期,在新生代期间随着印度板块与欧亚板块的碰撞,阿尔金断裂活化并相继发生了六次阶段性隆升,分别为:53-50 Ma、45-40 Ma、34-30 Ma、20-15 Ma、12-8 Ma、5 Ma至今.这与柴达木盆地内沉积事件具有良好的对应关系,具体表现为岩性变粗、沉积速率加快、地层呈角度不整合接触以及同构造生长地层的发育.其新生代的活动可划分为两个阶段,早期构造变形表现为基底韧性剪切,导致柴西北缘基底发生倾斜,形成了阿尔金斜坡;晚期由于应力的不断积累使得该地区应力场发生了变化,表现为大规模地表走滑.As a huge left-lateral sliping site,the Altyn Tagh Fault has attracted a lot of attention over the world. Its activity is the key to study the growth mechanism of the Tibetan Plateau. By reviewing previous thermochronological work and the sedimentary and structural responses in the northwestern margin of the Qaidam Basin,we try to summarize the uplift history of the Altyn Tagh and the coupling effect between basin and range. The Altyn Tagh Fault had activity in the Mesozoic,and then step into a long hiatus before the collision of the India Plate and Eurasian Plate in the Cenozoic,during which the Altyn Tagh Fault was reactivated and experienced stepwise tectonic uplift. Six prominent uplifting events have been recognized as followings： 53-50 Ma,45-40 Ma,34-30 Ma,20-15 Ma,12-8 Ma, 〈 5 Ma. The uplifting have good corresponding with the Qaidam Basin sedimentary events,it characterized by dilatation of the lithology,sedimentary speed accelerate,formation in angular unconformity contact and syntectonic growth strata of development. The Cenozoic activity patterns can be divided into two stages,and the early tectonic deformation is the ductile shearing in basement,which leads to the tilt of the basement of the northern Qaidam Basin and the formation of the Altyn slope. Due to the continuous accumulation of stress in the late stage,the stress field in the area has changed,which is characterized by large-scale strike-slip movement on surface.

关 键 词：阿尔金断裂 热年代学 盆山耦合 沉积响应 阶段性隆升 

分 类 号：P542.3[天文地球—构造地质学]