Late Cenozoic Activity of the Tashkurgan Normal Fault and Implications for the Origin of the Kongur Shan Extensional System, Eastern Pamir

作     者：Shenqiang Chen Hanlin Chen Shenqiang Chen;Hanlin Chen

作者机构：School of Earth SciencesZhejiang UniversityHangzhou 310027China Department of Earth SciencesETH ZurichZurich 8092Switzerland 

出 版 物：《Journal of Earth Science》 (地球科学学刊（英文版）)

年 卷 期：2020年第31卷第4期

页      面：723-734页

核心收录：

学科分类：070904[理学-构造地质学] 070902[理学-地球化学] 0709[理学-地质学] 07[理学] 

基　　金：funded by the National Natural Science Foundation of China (Nos. 41720104003 and 41330207) the National Science and Technology Major Project of China (Nos. 2017ZX05008-001 and 2016ZX05003-001) Chen S Q receives a PhD grant (No. 201706320352) from the China Scholarship Council 

主　　题：Pamir Late Cenozoic extension normal fault low-temperature thermochronology 

摘      要：In the northwest of the Himalayan-Tibetan Orogen, the ~250 km-long Kongur Shan extensional system in the eastern Pamir was formed during the convergence between the Indian and Asian plates. Tectonic activity of the Kongur Shan normal fault and the Tashkurgan normal fault can help to reveal the origin of east-west extension along the Kongur Shan extensional system. The Kongur Shan fault has been extensively studied, while the Tashkurgan fault calls for systemic research. In this study, low-temperature thermochronology including apatite fission track analysis and apatite and zircon(U-Th)/He analyses is applied to constrain the timing of activity of the Tashkurgan fault. Results indicate that the Tashkurgan fault initiated at 10–5 Ma, and most likely at 6–5 Ma. The footwall of the Tashkurgan fault has been exhumed at an average exhumation rate of 0.6–0.9 mm/a since the initiation of the Tashkurgan fault. Combined with previous research on the Kongur Shan fault, we believe that the origin of east-west extension along the Kongur Shan extensional system was driven by gravitational collapse of over-thickened Pamir crust.