Understanding how tectonic inheritance controls the evolution of mountain belts

了解构造继承如何控制山带的演化

• 批准号: RGPIN-2022-05360
• 负责人: White, Shawna
• 金额: $ 1.89万
• 依托单位: Saint Mary's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=755044
• 关键词: Understanding; how; tectonic; inheritance; controls

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.

拟议的研究将旨在确定以下的控制，即地球地壳的先前存在结构（例如断层）和异质性所定义的构造遗传对山地腰带（Orogens）额叶的山区建筑过程和断层重新激活（Orogens）具有。在山区建筑期间，现有的地下室结构是至关重要的，相对较弱的区域容易重新激活，并为岩浆，热和地下采购的金属提供了必要的途径。该研究计划将重点介绍北部阿巴拉契亚人（在加拿大和美国），在那里构成构造遗产是对山地建筑过程产生重大造型的影响；然而，显示前源性断层几何形状的证据是投机性的，而前源性断层的显着重新激活在很大程度上未被识别。我最近在NL阿巴拉契亚人的工作表明，构造继承意义重大，在阿巴拉契亚山区建筑期间，深层植根的断层已被多次重新激活。我假设在山区建造之前生成的类似地下室结构，并在魁北克和新英格兰（北阿巴拉契亚造山基因的南部延伸）中也发生了多次重新激活。拟议的研究将通过一项多学科研究计划来检验这一假设，该计划需要详细的地质映射，地层和结构分析，地质学和地球物理解释。如果在北阿巴拉契亚人沿线显示构造继承，则将大大修改如何形成阿巴拉契亚山脉的传统模型，以表明地下室过失与大量运输相关，并且这些断层具有复杂的运动历史。从经济角度来看，结果将允许鉴定在地下室断层重新激活过程中通常形成的关键地质结构，这些地质结构通常与石油陷阱或潜在的注入位点有关。地下室断层的重新激活也与流体流动发作直接相关，这对于将金属和从地壳深处传输到较浅的深度至较浅的深度以形成沉积托管矿物质系统并提供地热能资源至关重要。从地质阵神的角度来看，这些结果将使我们能够更好地理解遗传结构和地震事件之间发生的联系，而遗传性事件发生在造型的全球范围内。