Mio-Pliocene Tectonics and Exhumation Histories of the NW– and NE–Himalaya
Mio-Pliocene Tectonics and Exhumation Histories of the NW– and NE–Himalaya
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中新世构造和喜马拉雅西北和东北的折返历史
DOI：
10.18814/epiiugs/2020/020024
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发表时间：
2020
期刊：
影响因子：
3.1
通讯作者：
R. Manmohan
中科院分区：
文献类型：
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作者：
R. Manmohan
碰撞喜马拉雅造山带通常表现为从喜马拉雅山西北到东北的横向上基本一致，具有几乎相似的地质和构造背景。尽管喜马拉雅山自数百万年来一直活跃的连续辐合和降水，但喜马拉雅西北和东北喜马拉雅不同地区的热年代/冷龄模式、隆起和折返率随结构位置的变化而变化，如穹窿/窗/同步峰、瀑布/推覆结构以及沿不同主要断层的逆冲/逆冲。这些表面结构似乎反映了喜马拉雅主逆冲断层（MHT）的几何形状和运动学以及在 MHT 斜坡上形成的复式结构。这些观测结果表明，在这种以陡峭地形和强烈风暴为特征的构造活跃环境中，热年代/冷龄模式和折返模式并不反映降水梯度或驱动百万年时间尺度的变形。相反，折返模式是由局部构造控制的，而局部构造是由 MHT 及其相关结构的地下几何形状决定的。
The collisional Himalayan orogen is commonly presented as largely laterally uniform from the NW– to NE–Himalaya, with almost similar geological and tectonic settings. Despite active continuous convergence and precipitation since many million years in the Himalaya, thermochronological/cooling age pattern, uplift and exhumation rates vary in different parts of NW– and NE–Himalaya as a function of structural positions such as dome/window/synform, klippen/nappe structures and thrusting/back-thrusting along different major faults. These surface structures appear to reflect the geometry and kinematics of the Main Himalayan Thrust (MHT) and duplex structures formed over the ramp of the MHT. These observations suggest that in this tectonically-active setting characterized by steep topography and intense storms, thermochronological/cooling age pattern and exhumation patterns do not mirror precipitation gradients or drive deformation on million-year timescales. Rather, exhumation patterns are controlled by local tectonics that is dictated by the subsurface geometry of the MHT and its associated structures.