Pure and applied problems in metamorphic geology

变质地质学的纯粹问题和应用问题

• 批准号: RGPIN-2022-02988
• 负责人: Pattison, David
• 金额: $ 3.72万
• 依托单位: University of Calgary
• 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=755106
• 关键词: Pure; applied; problems; metamorphic; geology

Over half of Canada's land surface is underlain by metamorphic and igneous rocks, and by far the majority of Canada's mineral deposits occur in these areas. Understanding how metamorphic and igneous rocks form is thus of scientific and societal interest. My research program is concerned with the metamorphic half of the relationship, namely metamorphic petrology (= the scientific study of the make-up and genesis of metamorphic rocks). Metamorphic petrology is the primary probe of the burial, heating and exhumation of Earth's crust arising from plate tectonic interactions. When combined with structural, geochronological and thermochronological techniques, metamorphic petrology helps unravel the evolution of Earth's plate tectonic interactions through time, and informs the formation and modification of mineral deposits. Researchers in other fields of geoscience (structure, tectonics, ore deposits) rely on the estimates of pressure (depth) and temperature (P and T) that metamorphic petrologists provide from reading the metamorphic rock record. If inaccurate estimates are provided, it sets back advances in all these areas. The long-term objectives of my research program are thus two-fold: (1) to advance our understanding of metamorphic recrystallization, the aim being to enhance the reliability of our estimates of pressure (depth) and temperature of metamorphosed rocks; and (2) to apply this enhanced understanding in concert with allied techniques to provide insights into the evolution of Earth's orogenic (mountain) belts, especially the southern Canadian Cordillera. Each objective stimulates progress in the other. Proposed short-term objectives include: (1-1)Creating a database of natural mineral assemblages and mineral compositions from metamorphic settings of varying P and T from around the world, and using these to test and refine our thermodynamic modelling of these relationships; (1-2)Creating the first comprehensive mineral assemblage map of Barrow's Zones in Scotland, arguably the most famous and most studied metamorphic sequence on Earth; (1-3)Assessing how reliable are the depths of metamorphism that are inferred from phase equilibrium analysis of metamorphic rocks; (1-4)Analyzing the degree to which rock deformation catalyzes metamorphic recrystallization; and (2-1)Determining the evolution of the Valhalla complex, Shuswap domain, British Columbia, a "type example" of a core complex ( = an "uplift" of mid-deep crustal rocks bounded by faults, such found in extensional oceanic and continental settings around the world). From a training perspective, engagement in this research will educate the next generation of geoscientists, providing them with observational, analytical, computational, interpretational and communication skills that are highly valued in academia, government and industry. They will be in the vanguard of the future generation of adaptable, interdisciplinary geoscientists Canada needs.

加拿大一半以上的陆地表面覆盖着变质岩和火成岩，迄今为止加拿大的大部分矿藏都产于这些地区。因此，了解变质岩和火成岩是如何形成的具有科学和社会意义。我的研究项目涉及变质关系的一半，即变质岩石学（=变质岩的组成和成因的科学研究）。 变质岩石学是板块构造相互作用引起的地壳埋藏、加热和折返的主要探测手段。当与结构、地质年代学和热年代学技术相结合时，变质岩石学有助于揭示地球板块构造相互作用随时间的演变，并为矿床的形成和改造提供信息。地球科学其他领域（结构、构造、矿床）的研究人员依赖变质岩石学家通过阅读变质岩记录提供的压力（深度）和温度（P 和 T）估计值。如果提供不准确的估计，就会阻碍所有这些领域的进展。 因此，我的研究计划的长期目标有两个：（1）增进我们对变质重结晶的理解，目的是提高我们对变质岩压力（深度）和温度的估计的可靠性； (2) 将这种加深的理解与相关技术结合起来，以深入了解地球造山带，特别是加拿大南部科迪勒拉山脉的演化。 每个目标都会刺激另一个目标的进步。 拟议的短期目标包括： (1-1) 创建一个来自世界各地不同 P 和 T 的变质环境中的天然矿物组合和矿物成分的数据库，并使用这些数据库来测试和完善我们对这些关系的热力学模型； (1-2)绘制苏格兰巴罗带的第一张综合矿物组合图，这可以说是地球上最著名、研究最多的变质序列； (1-3)评估由变质岩的相平衡分析推断的变质深度的可靠性； (1-4)分析岩石变形催化变质再结晶的程度； (2-1) 确定不列颠哥伦比亚省 Shuswap 域的 Valhalla 复合体的演化，这是核心复合体的“类型示例”（= 以断层为边界的中深地壳岩石的“隆起”，如在伸展海洋中发现的以及世界各地的大陆环境）。 从培训的角度来看，参与这项研究将教育下一代地球科学家，为他们提供在学术界、政府和工业界高度重视的观察、分析、计算、解释和沟通技能。他们将成为加拿大所需的下一代适应性强、跨学科的地球科学家的先锋。