Applied thermochronology and the isotopic record of low-temperature crustal-scale tectonic processes

低温地壳尺度构造过程的应用热年代学和同位素记录

• 批准号: 355242-2013
• 负责人: Schneider, David
• 金额: $ 1.97万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=527722
• 关键词: Applied; thermochronology; isotopic; record; low

Mountain belts form in many ways but the two most common end-members are through squeezing the Earth's crust (compression) and stretching it (extension). A particular focus of this Discovery research program is aimed at the cores of mountain belts where most of the transport of crustal heat and mass occurs. Resolving a rock's thermal evolution in these settings has direct influence on the advancement of geodynamic, climate, and landscape evolution models. The processes that form rocks at high temperatures in mountain belts are reasonably well characterized. Little is known, however, of the timescales that rocks take to emerge at the Earth's surface, nor the effects of the deformation pathway on the isotopic systems. To better understand these processes, a quantitative understanding of the thermal evolution of rocks as they move through the Earth's outer shell and under a range of geologic settings is required. This research proposal addresses these needs by advancing innovative scientific approaches that shed light on rock's change in temperature, depth and deformation-state through time during mountain growth and decay. The rock's "travel log" is gleaned from detailed chemical and structural characterization of mineral assemblages and textures. Collectively, these make up the fingerprint of the tectonic process at work in mountains and advance our knowledge of how long-term, crustal-scale processes link to the dynamics of climate, surface processes and the Earth's solid interior. Together with Discovery Grant support, my work embarks upon a new phase of Earth science research involving students and collaborators, developing innovative geochronology techniques, and rewarding my students with having access to, and training on, world-class instruments. Although concentrating on fundamental issues such as the life cycle of mountain belts, this research has impacts through the Earth Sciences, from submicron-scale isotope mobility to mega-scale tectonism. More directly, this research has specific applications to natural resource exploration within Canada, including determining the timing and duration of ore-bearing fluid flow and the burial history of petroleum reservoirs.

山脉带的形成有很多种方式，但最常见的两种是挤压地壳（压缩）和拉伸地壳（伸展）。这一发现研究计划的一个特别重点是针对山区带的核心，那里发生了大部分地壳热量和质量的传输。在这些背景下解决岩石的热演化直接影响到地球动力学，气候和景观演化模型的进步。在高温下在山区形成岩石的过程是相当好的特点。然而，人们对岩石在地球表面出现的时间尺度知之甚少，也不知道变形路径对同位素系统的影响。为了更好地理解这些过程，需要定量地了解岩石在穿过地球外壳和一系列地质环境时的热演化。这项研究提案通过推进创新的科学方法来满足这些需求，这些方法揭示了岩石在山脉生长和衰退期间随着时间的推移在温度，深度和变形状态方面的变化。岩石的“旅行日志”是从矿物组合和纹理的详细化学和结构特征中收集的。总的来说，这些构成了在山区起作用的构造过程的指纹，并增进了我们对长期地壳规模的过程如何与气候动态、地表过程和地球固体内部联系的认识。随着发现补助金的支持，我的工作开始了地球科学研究的一个新阶段，涉及学生和合作者，开发创新的地质年代学技术，并奖励我的学生有机会获得，并培训，世界一流的仪器。虽然集中在基本问题，如生命周期的山区带，这项研究的影响，通过地球科学，从亚微米尺度的同位素流动性的大规模构造。更直接地说，这项研究对加拿大境内的自然资源勘探有具体的应用，包括确定含矿流体流动的时间和持续时间以及石油储层的埋藏历史。