The geometry and kinematics of first-order structural systems on the Tibetan Plateau (TP) are key to understanding how the continental crust and lithosphere deformed during the India-Asia collision. The Altyn Tagh Fault (ATF), which is a large-scale fault bounding the northern edge of the Tibetan Plateau (NTP), absorbed as much as one-third of the total convergence in the collision between India and Eurasia. The Baiganhu Fault, in the western Qimen Tagh Mountains on the NTP, is recognized as belonging to the ATF and has played an important role in the development of its adjacent region. Due to the high elevation and harsh working conditions, this fault has received little attention, and the timing of its activation has not been thoroughly researched. In this study, we collected granite samples from close to the Baiganhu Fault in the Qimen Tagh Mountains, and used zircon and apatite fission track dating to constrain the timing of activation for this fault. The fission track ages and HeFTy modeling results reveal two rapid cooling stages along the Baiganhu Fault: one during the Jurassic-cretaceous (~180–120 Ma) and the second since the mid-Miocene (~15–10 Ma), consistent with other regions on the NTP. The first fast exhumation event was a far-field response to the Lhasa-Qiangtang collision, and the second stage most likely resulted from crustal thickening, with a connection to the ATF occurring at around ~15–10 Ma.

青藏高原（TP）一阶结构系统的几何学和运动学是了解印度洋与亚洲碰撞期间大陆地壳和岩石圈如何变形的关键。Altyn Tagh断层（ATF）是青藏高原（NTP）北部边缘的大型断层，吸收了印度与欧亚大陆碰撞总收敛量的三分之一。NTP在祁门塔河西部的白干湖断层被认为属于ATF，并在其邻近地区的发展中发挥了重要作用。由于高海拔和恶劣的工作条件，该故障很少引起注意，并且尚未对其激活的时机进行深入研究。在这项研究中，我们从祁门塔格山白干湖断层附近采集了花岗岩样品，并利用锆石和磷灰石裂变径迹法来约束该断层的活化时间。裂变径迹年龄和HeFTy模拟结果揭示了沿白干湖断层的两个快速冷却阶段：一个在侏罗纪-白垩纪（〜180–120 Ma）期间，第二个自中新世中期（〜15-10 Ma）以来，与其他相一致。 NTP上的区域。第一个快速发掘事件是对拉萨-ian塘碰撞的远场响应，第二个阶段很可能是地壳增厚造成的，与ATF的关系发生在约15-10 Ma。裂变径迹年龄和HeFTy模拟结果揭示了沿白干湖断层的两个快速冷却阶段：一个在侏罗纪-白垩纪（〜180–120 Ma）期间，第二个自中新世中期（〜15-10 Ma）以来，与其他相一致。 NTP上的区域。第一个快速发掘事件是对拉萨-ian塘碰撞的远场响应，第二个阶段很可能是地壳增厚造成的，与ATF的关系发生在约15-10 Ma。裂变径迹年龄和HeFTy模拟结果揭示了沿白干湖断层的两个快速冷却阶段：一个在侏罗纪-白垩纪（〜180–120 Ma）期间，第二个自中新世中期（〜15-10 Ma）以来，与其他相一致。 NTP上的区域。第一个快速发掘事件是对拉萨-ian塘碰撞的远场响应，第二个阶段很可能是地壳增厚造成的，与ATF的关系发生在约15-10 Ma。