The Xianshuihe Fault Belt (XSF), along which the syntectonic Zheduoshan batholith was emplaced, has great significance for the reconstruction of the tectonic framework in the eastern margin of the Tibetan Plateau. In this contribution, formation process and evolution of the XSF are discussed based on the structural deformation in the field and the geochronology of Zheduoshan batholith. The results show that the XSF current arc‐shaped protrusion to the north‐east probably was formed by a fracture of the clockwise rotation compression that extended northward to the periphery with the eastern Himalayan tectonic syntaxis as the centre. It is a complex fault belt formed by the superposition of multi‐stage structures. In the early‐stage formation and evolution of the XSF, the Oligocene‐Miocene migmatite zone and Miocene granites of the Zheduoshan batholith were emplaced. Among them, the lower limit of the XSF's initial activity time was not less than 47 Ma that was limited by the Zircon U–Pb geochronology of migmatite zone formed under the compression system. During the emplacement of Miocene granites, the XSF underwent a process from compression to sinistral strike‐slip, and the geochronology indicates that the onset of the XSF sinistral strike slip should not be less than 14 Ma. After syntectic magmatism, the XSF also experienced the shear deformation (from ductile to brittle) with sinistral kinematics. ⁴⁰Ar‐³⁹Argeochronology results show that the ductile shear deformation mainly occurred around 5.5–3.2 Ma and accompanied a staged and differential uplift from north to south. It extended to the south along the weak crustal zone of Anninghe, Daliangshan, Xiaojiang, and other faults, forming the Xianshuihe–Anninghe–Xiaojiang sinistral strike‐slip fault system on the eastern margin of the Tibetan Plateau, and large‐scale sinistral strike slip began around 5 Ma. Our new insights lay a foundation for understanding and dissecting the formation and evolution of the Tibetan Plateau eastern margin.

中文翻译：

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青藏高原东缘鲜水河断裂带的形成与演化：受构造变形和年代学的制约

咸水河断层带（XSF）被构造成同构的折多山岩基，对青藏高原东缘的构造构架的重建具有重要意义。在此贡献的基础上，根据折多山岩基的野外构造变形和年代学，讨论了XSF的形成过程和演化。结果表明，XSF向东北的弧形凸起可能是由顺时针旋转压缩的断裂形成的，该断裂向北延伸到以喜马拉雅东部构造语法为中心的外围。它是由多级结构叠加形成的复杂断层带。在XSF的早期形成和发展过程中，设置了蛇头山岩基的中新世-中新世辉铁矿带和中新世花岗岩。其中，XSF初始活动时间的下限不小于47 Ma，这受压缩系统下形成的辉石岩带锆石U–Pb年代学的限制。在中新世花岗岩的沉积过程中，XSF经历了从压缩到左旋走滑的过程，地质年代学表明，XSF左旋走滑的发作时间不应小于14 Ma。经过共晶岩浆作用之后，XSF还通过左旋运动学经历了剪切变形（从延性到脆性）。初始活动时间不少于47 Ma，这受压缩系统下形成的辉石矿区的锆石U–Pb年代学限制。在中新世花岗岩的沉积过程中，XSF经历了从压缩到左旋走滑的过程，地质年代学表明，XSF左旋走滑的发作时间不应小于14 Ma。经过共晶岩浆作用之后，XSF还通过左旋运动学经历了剪切变形（从延性到脆性）。初始活动时间不少于47 Ma，这受压缩系统下形成的辉石矿区的锆石U–Pb年代学限制。在中新世花岗岩的沉积过程中，XSF经历了从压缩到左旋走滑的过程，地质年代学表明，XSF左旋走滑的发作时间不应小于14 Ma。经过共晶岩浆作用之后，XSF还通过左旋运动学经历了剪切变形（从延性到脆性）。⁴⁰ Ar ^39的年代学结果表明，韧性剪切变形主要发生在5.5-3.2 Ma附近，并伴随着从北向南的阶段性和差异性隆升。它沿着安宁河，大山山，小江等断裂的弱地壳区向南延伸，形成了青藏高原东缘的咸水河—安宁河—小江左旋走滑断裂系统，并形成了大规模的左旋走滑带。开始于5 Ma。我们的新见识为理解和剖析青藏高原东缘的形成和演化奠定了基础。