Ore Systems, Tectonics and the Geochemical Cycles of Metals

矿石系统、构造和金属地球化学循环

• 批准号: RGPIN-2018-04961
• 负责人: Fayek, Mostafa
• 金额: $ 3.13万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712619
• 关键词: Ore; Systems; Tectonics; Geochemical; Cycles

Global geochemical cycles maintain the Earth in a more-or-less steady state. Fluid-rock interaction is a major process which helps maintain these geochemical cycles and is responsible for mass (e.g., elemental) transport in near-surface environments (e.g., U deposits) as well as the deeper crust (e.g., Orogenic Au deposits). Although we know a considerable amount about certain geochemical cycles such as the carbon and sulfur cycles, there are gaps in our understanding of geochemical cycles of metals and their relation to tectonics and ore systems. Identifying these gaps or inconsistencies in the global metal geochemical balance may point to similar gaps in our knowledge of potential resources. My research aims to address these gaps by understanding the processes that extract, transport and concentrate metals, and the relationship between large-scale (crustal) fluid events and mass transport at the regional, local and atomic levels. In so doing, I plan to make fundamental contributions to science that will find application in the environmental sciences and mineral exploration. Most elements of economic value (e.g., Au, U) occur in the Earth's crust in concentrations of a few parts per million (ppm) or lower. For these metals to be economically extractible they must accumulate in the Earth's crust in sufficient concentrations. Therefore, several processes must occur at the appropriate time. Isotopes can provide information on these processes that distribute and concentrate metals in natural systems. The utility of using the fractionation of traditional light stable isotopes (H, C, O, N, and S) and Pb as tracers of fluid-solid interactions, geothermometers, mass transport and contaminants is well established, and radiogenic isotopes (e.g., U-Pb) are useful chronometers of fluid events. However, the use of non-traditional light isotopes such as B and Li, and transition- (e.g., Fe) and other heavy-metal isotopes (e.g., U), is in its infancy. Therefore, during this funding period my students and I plan to combine traditional and non-traditional isotope systems to address some key questions related to uranium ore systems. We plan to combine field observations and analysis of natural samples to verify our observations and interpretations. The novelty of the work is that diverse mineralogical and isotopic techniques are combined to provide insights into the genesis of mineral deposits. This proposal involves extensive training of Highly Qualified Personnel in the form of graduate and undergraduate students, and collaborative work with visiting scientists from other Universities and government institutions. In particular, the collaborative work proposed will give students an unusually wide and diverse background in science, preparing them to develop the research of the future.

全球地球化学循环使地球保持在或多或少的稳定状态。 流体-岩石相互作用是一个主要过程，有助于维持这些地球化学循环，并负责近地表环境（例如铀矿床）以及更深地壳（例如造山金矿床）中的质量（例如元素）传输。 尽管我们对某些地球化学循环（例如碳和硫循环）了解相当多，但我们对金属地球化学循环及其与构造和矿石系统的关系的理解存在差距。识别全球金属地球化学平衡中的这些差距或不一致可能会指出我们对潜在资源的了解中存在类似的差距。我的研究旨在通过了解提取、运输和浓缩金属的过程，以及区域、局部和原子层面的大规模（地壳）流体事件与质量运输之间的关系来解决这些差距。在此过程中，我计划为科学做出基础性贡献，并将其应用于环境科学和矿物勘探。 大多数具有经济价值的元素（例如金、铀）在地壳中的浓度为百万分之几 (ppm) 或更低。为了经济地开采这些金属，它们必须在地壳中积累足够的浓度。因此，几个过程必须在适当的时间发生。同位素可以提供有关自然系统中金属分布和浓缩过程的信息。使用传统光稳定同位素（H、C、O、N 和 S）和 Pb 的分馏作为流固相互作用、地温计、质量传输和污染物的示踪剂的效用已得到充分证实，而放射性同位素（例如 U -Pb）是流体事件的有用计时器。然而，非传统轻同位素（例如 B 和 Li）以及过渡同位素（例如 Fe）和其他重金属同位素（例如 U）的使用还处于起步阶段。因此，在这个资助期间，我和我的学生计划将传统和非传统同位素系统结合起来，解决与铀矿石系统相关的一些关键问题。 我们计划结合实地观察和自然样本分析来验证我们的观察和解释。这项工作的新颖之处在于，结合了不同的矿物学和同位素技术，为矿床的成因提供了见解。 该提案涉及对研究生和本科生等高素质人才的广泛培训，以及与其他大学和政府机构的访问科学家的合作。特别是，所提出的合作工作将为学生提供异常广泛和多样化的科学背景，为他们开展未来的研究做好准备。