New paleomagnetic constraints on middle Miocene strike‐slip faulting along the middle Altyn Tagh Fault

作者：Bingshuai Li, Maodu Yan, Weilin Zhang, Xiaomin Fang, Qingquan Meng, Jinbo Zan, Yi Chen, Dawen Zhang, Yongpeng Yang, Chong Guan · 发表于：Journal of Geophysical Research Solid Earth · 年份：2017 · DOI：10.1002/2017jb014058 · 被引用次数：54 · 研究领域：Geological and Geochemical Analysis、earthquake and tectonic studies、Geomagnetism and Paleomagnetism Studies

Abstract Knowledge of the evolution of the Altyn Tagh Fault (ATF) has significant implications for our understanding of the tectonic deformation of the Tibetan Plateau. Controversy exists regarding the formation of the orocline‐like arcuate structures or curved thrust faults south of the ATF. In this paper, we conducted a paleomagnetic rotation study of the Akatengnengshan (AK) and Youshashan (YSS) anticlines to determine whether the changes in the anticlines' axes were caused by frictional drag associated with sinistral strike‐slip faulting along the ATF. No significant paleomagnetic rotations during the last 20 Ma were observed at the Xichagou and Laomangai localities, which are situated along the YSS anticline, whereas significant counterclockwise (CCW) rotations of ~50° that occurred between ~16.2 and 11.1 Ma were noted at the Yitunbulake locality, which lies along the western edge of the AK anticline. This amount of CCW rotation is consistent with the difference in axes between the AK and YSS anticlines. Combined with other geological evidence, we believe that the middle ATF was active between ~16 and 11 Ma. Frictional drag associated with sinistral strike‐slip motion likely resulted in the ~50° CCW rotation of the AK anticline, which was originally straight or parallel to the YSS anticline. There was concentrated or insignificant strike‐slip faulting along the middle ATF before ~16 Ma, but rapid and distributed (< 40 km) strike‐slip faulting occurred between ~16 and ...