Tectonic inheritance, orogenesis, and seismicity

山带形成于构造板块的交汇处，最终形成于板块碰撞处。喜马拉雅是当今地球上最年轻也是最大的山带系统之一。了解这一高度暴露的山带对于解释岩石记录中许多更古老、暴露程度更低的系统至关重要。它是整个地质时代构造思想的标志性模板。这个项目将研究已经存在的地壳断层（这里称为继承基底断层）、造山过程和地震之间的相互作用。为了充分了解造山过程，包括在活动山前和远离活动山前的地震，必须在造山之前清楚地约束碰撞板块的几何形状。本研究选择喜玛拉雅山系，是因为其保存完好且演化较近，因此限制了构造叠印，并使喜玛拉雅山和前喜玛拉雅山变形得以区分。预计该项目将为了解格伦维尔山脉、阿巴拉契亚山脉和加拿大科迪勒拉山脉等较老山带的基底断层演化提供关键环节。这些深层构造控制地震破裂，影响横向沉积厚度变化和褶皱冲断带几何形状，并通过前陆沉积盆地圈定矿产资源和控制油气运移。在喜马拉雅系统的情况下，这种隐藏的地质灾害控制可能对地球上人口最稠密的地区之一产生巨大的影响。我假设印度板块内主要的东北向岩石圈规模断层在喜马拉雅山脉之下继续存在，并导致了沿山脉带长度表现出的大量变化。我进一步假设这些深层结构反复被激活。喜马拉雅变质核压力-温度演化的沿向变化，前陆褶皱-冲断带的侧向斜坡和/或沿向沉积厚度的变化，以及现今印度板内和喜马拉雅地震活动的分区，都可以记录到继承断裂的再活化历史。这些潜在的相互作用将通过hqp主导的几个主题进行探索，这些主题包括：与远离喜马拉雅锋面的基底断层重新激活相关的板内活动构造的研究；利用地震资料重建前陆褶皱冲断带实地和实验室调查，以评估沿走向的应变变化，变质峰条件和喜马拉雅变质岩心的挖掘；连接当今地震活动性、应力轨迹和基底断层的数值应力模拟；并进行了动态缩放离心机的变形模拟建模。

Mountain belts are constructed at the convergence and ultimately at the collision site of tectonic plates. The Himalaya is one of the youngest and certainly the largest mountain belt system on the planet today. Understanding this superbly exposed mountain belt is critical for the interpretation of many older and more poorly exposed systems in the rock record. It is an iconic template for tectonic thought for all of geologic time. This program will study the interplay between pre-existing crustal faults (termed here inherited basement faults), mountain building processes, and earthquakes. To fully understand mountain-building processes, including earthquakes in and away from the active mountain front, it is imperative to clearly constrain the geometry of the colliding plates prior to mountain building. The Himalayan system is chosen in this proposal because of its unrivaled preservation and recent evolution, which consequently limits tectonic overprinting and enables the distinction between Himalayan and pre-Himalayan deformation. It is anticipated that this program will provide key links to understand basement faults in the evolution of older mountain belts, such as the Grenville, the Appalachians, and the Canadian Cordillera. Such deep-seated structures are interpreted to control earthquake ruptures, influence lateral sedimentary thickness variations and fold-thrust belt geometry, and to localize ore resources and control hydrocarbon migration through foreland sedimentary basins. In the case of the Himalayan system, such hidden geohazard controls can have tremendous repercussions for one of the most densely populated regions on Earth. I postulate that major northeast-trending lithospheric-scale faults within the Indian plate continue beneath the Himalayan mountains and contribute to a multitude of changes expressed along the length of the mountain belt. I further hypothesize that these deep-seated structures have repeatedly reactivated. The reactivation history of the inherited faults may be recorded in along-strike changes in the pressure-temperature evolution of the metamorphic core of the Himalaya, as lateral ramps and/or along-strike sediment thickness variations in the foreland fold-thrust belt, and in the present-day partitioning of Indian intraplate and Himalayan seismicity. These potential interactions will be explored through several HQP-led themes that involve: investigation of intraplate active tectonics related to basement fault reactivation away from the Himalayan front; reconstruction of the foreland fold-thrust belt using seismic data; field and lab investigations to assess along-strike variation in strain, metamorphic peak conditions, and exhumation of the Himalayan metamorphic core; numerical stress modelling linking present-day seismicity, stress trajectories, and basement faults; and dynamically-scaled centrifuge analogue modelling of deformation.