Pressure‐temperature (P‐T) conditions and high‐resolution paths from 11 garnet‐bearing rocks collected across Himalayan fault systems exposed along the Bhagirathi River (Uttarakhand, NW India) reveal the tectonic conditions responsible for their growth. A garnet from the Tethyan metasedimentary unit has a 50.3 ± 0.6 Ma (Th‐Pb, ±1σ) monazite inclusion, suggesting that ductile mid‐crustal metamorphism occurred synchronously or soon after (<10 Myr) India‐Asia collision, depending on timing. High‐resolution garnet P‐T paths from the same rock show ∼1 kbar fluctuations in P as T increases over a ∼20°C interval, consistent with a period of erosion. We report garnets from the Main Central Thrust (MCT) hanging wall that have Eocene to Miocene monazite ages, and one garnet yields paths consistent with motion along the Main Himalayan Thrust (MHT) décollement. Most high‐resolution MCT footwall P‐T paths fluctuate in P (±1 kbar) as T increases, consistent with imbrication and paths from equivalent structural assemblages in central Nepal. Like those rocks, MCT footwall (Lesser Himalayan Formation, LHF) monazite ages are Early Miocene (9.3 ± 0.6 Ma) to Pliocene (3.0 ± 0.2 Ma). The results demonstrate the consistency in timing and conditions across the MCT at locations ∼650 km apart. If the present‐day Himalayan tectonic framework has not significantly changed since the Pliocene, the LHF duplex can be considered when attributing seismic events to particular faults. The MHT is undisputedly the significant factor in accommodating Himalayan seismic activity, but MCT footwall faults may explain some shallower hypocenters, without the need for unusual MHT geometries.

中文翻译：

---

沿印度西北印度Bhagirathi断面暴露的喜马拉雅断层的高分辨率P-T-Time路径：对喜马拉雅造山带构造和持续变形的影响

压力温度（PT）条件和从沿Bhagirathi河（印度西北部，北阿坎德邦）暴露的喜马拉雅断层系统中收集的11颗石榴石承载的高分辨率岩石路径揭示了造成其生长的构造条件。Tethyan沉积沉积单元的石榴石的50.3±0.6 Ma（Th-Pb，± 1σ）独居石包裹体，表明延展性中地壳变质同步发生或在（<10 Myr）印度-亚洲碰撞后不久发生，具体取决于时间。来自同一块岩石的高分辨率石榴石P‐T路径显示，随着T在约20°C的间隔内增加，P中的〜1 kbar波动，与侵蚀时间一致。我们报道了从中部主推力（MCT）悬挂壁上的石榴石具有始新世至中新世独居时代，并且一副石榴石产生的路径与沿喜马拉雅主冲（MHT）背斜的运动一致。随着T的增加，大多数高分辨率的MCT下壁P-T路径都在P（±1 kbar）内波动，这与尼泊尔中部的岩溶作用和来自等效结构组合的路径一致。像这些岩石一样，MCT底盘（Lesser Himalayan组，LHF）独居石年龄为中新世早期（9.3±0.6 Ma）至上新世（3.0±0.2 Ma）。结果表明，整个MCT的时间和条件在相距约650公里的位置上具有一致性。如果自上新世以来当今的喜马拉雅构造框架未发生重大变化，则在将地震事件归因于特定断层时，可以考虑采用LHF双工。毫无疑问，MHT是适应喜马拉雅地震活动的重要因素，但是MCT底盘断层可以解释一些较浅的震源，而无需异常的MHT几何形状。