The growth of the Tibetan Plateau is related to the Cenozoic India‐Eurasia plate collision; however, its growth and evolution to its present margins remain matters of debate. The Qilian Shan, which is located along the northeastern margin of the Tibetan Plateau, plays a central role in understanding the outward growth of the plateau. In this paper, we present new low‐temperature thermochronologic data from the hanging wall of the Huangcheng‐Shuangta fault (HSF) and the Lenglongling west region in the eastern part of the Qilian Shan. Cooling ages and thermal history modeling show increased exhumation rates at ~15 Ma along the HSF and ~5 Ma in the Lenglongling west region. We suggest that the middle Miocene beginning of rapid exhumation reflects the expansion of the larger Qilian Shan driven by thrust fault systems. The fast Pliocene exhumation may have been related to left‐lateral motion on the Haiyuan fault during the late stage of orogenic development. Post‐Miocene episodes of rapid exhumation in the eastern Qilian Shan are similar to those in other regions on the northeastern margin of the Tibetan Plateau, suggesting that middle to late Miocene initiation or acceleration of crustal shortening occurred along this margin.

中文翻译：

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青藏高原东北部祁连山新生代发掘活动：低温热年代学的证据

青藏高原的增长与新生代印度-欧亚大陆板块碰撞有关。然而，它的增长和演变到现在的边缘仍然是有争议的问题。祁连山位于青藏高原的东北边缘，在了解高原的向外增长方面起着核心作用。在本文中，我们从from城—双塔断层（HSF）的悬壁和祁连山东部的冷龙岭西部地区提供了新的低温热年代学数据。冷却年龄和热历史模型表明，沿HSF的〜15 Ma和冷龙岭西部地区的〜5 Ma出土率增加。我们认为，快速发掘的中新世中期开始反映了由逆冲断层系统驱动的较大的祁连山的扩张。上新世快速发掘可能与造山发育后期海原断层的左旋运动有关。祁连山东部中新世后快速发掘的事件与青藏高原东北缘的其他地区相似，这表明中新世中晚期到地壳缩短发生在该边缘。