Understanding how tectonic inheritance controls the evolution of mountain belts

提出的研究将旨在确定构造继承（由已存在的构造（如断层）和地壳的非均质性定义）对山带（造山带）前缘的造山过程和断层再激活（运动）的控制作用。在造山过程中，已存在的基底构造是关键的，相对薄弱的区域，容易被重新激活，并为岩浆、热量和基底源金属的迁移提供了必要的途径。该研究项目将集中在北阿巴拉契亚山脉（加拿大和美国），那里的构造继承被认为对造山过程有重大的造山带规模影响；然而，表明前造山断层几何形状的证据是推测性的，前造山断层的重大再激活在很大程度上没有被认识到。我最近在北阿巴拉契亚山脉的工作表明，构造继承是重要的，在阿巴拉契亚山脉的构造过程中，深基底根植断层多次被重新激活。我假设，类似的基底结构，在造山之前就已经形成，并多次被激活，也出现在魁北克和新英格兰，北阿巴拉契亚造山带的南部延伸。拟议的研究将通过一个多学科研究项目来检验这一假设，该项目需要详细的地质测绘、地层和构造分析、地质年代学和地球物理解释。如果沿北阿巴拉契亚山脉显示出构造继承，那么解释阿巴拉契亚山脉如何形成的传统模型将得到重大修正，以表明基底断层与大量的搬运有关，并且这些断层具有复杂的运动历史。从经济角度来看，结果将允许识别通常在基底断层重新激活期间形成的关键地质构造，这些构造通常与石油圈闭或潜在的注入点有关。基底断裂的重新激活也与流体流动事件直接相关，流体流动是将地壳深处的金属和热量向上输送到较浅的地方，形成沉积矿物系统并提供地热能源的关键。从地质灾害的角度来看，这些结果将使我们更好地理解发生在世界各地造山带前陆的继承构造与地震事件之间的联系。

The proposed research will aim to determine the control that tectonic inheritance, defined by pre-existing structures (e.g. faults) and heterogeneity of the Earth's crust, has on mountain building processes and fault reactivation (movement) at the frontal parts of mountain belts (orogens). During mountain building, pre-existing basement structures are critical, relatively weak zones prone to reactivation and provide necessary pathways for the migration of magma, heat, and basement-sourced metals. The research program will focus on the Northern Appalachians (in Canada and the US) where tectonic inheritance has been invoked as having major orogen-scale impacts on mountain building processes; however, evidence showing pre-orogenic fault geometry is speculative and significant reactivation of pre-orogenic faults is largely unrecognized. My recent work in the NL Appalachians demonstrates that tectonic inheritance is significant and that deep-basement rooted faults have been reactivated multiple times during Appalachian Mountain building. I hypothesize that analogous basement structures, generated prior to mountain building and reactivated multiple times, also occur in both Quebec and New England, the southern extension of the Northern Appalachian orogen. The proposed research will test this hypothesis through a multidisciplinary research program requiring detailed geological mapping, stratigraphic and structural analyses, geochronology, and geophysical interpretation. If tectonic inheritance is shown along the Northern Appalachians, traditional models that explain how the Appalachian Mountains were formed will be significantly revised to show that basement-faults are associated with a significant amount of transport and that these faults have a complex history of motion. From an economic perspective, results will allow for the identification of critical geologic structures typically formed during basement fault reactivation, which are often associated with petroleum traps or potential injection sites. Reactivation of basement faults is also directly associated with fluid flow episodes, which are critical to transport metals and heat from deep in the Earth's crust upwards to shallower depths to form sedimentary-hosted mineral systems and provide geothermal energy resources. From a geohazard perspective, these results will allow us to better understand the link between inherited structure and seismic events, which occur in the foreland of orogen's worldwide.