A Theoretical Basis for Mineralogy and the Behaviour of Minerals in Earth Processes

矿物学和矿物在地球过程中的行为的理论基础

• 批准号: RGPIN-2020-05675
• 负责人: Hawthorne, Frank
• 金额: $ 2.19万
• 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: 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=754971
• 关键词: Theoretical; Basis; Mineralogy; Behaviour; Minerals

Minerals are the fundamental materials of the Earth, and if we wish to understand the processes which formed the Earth, and which continue to modify its landscape and the human environment, we need to understand the behaviour of minerals under the full spectrum of conditions experienced on Earth. This proposal focuses on a wide variety of minerals in an attempt to understand the atomic-scale factors affecting their constitution and behaviour, and to use this understanding to rationalize and predict their behaviour at the macroscopic scale. I use various forms of radiation (X-rays, neutrons) to 'see' into a mineral at the atomic scale via diffraction, and to derive the arrangement of atoms from which it is built. Details concerning atomic disorder can be seen with spectroscopy using other forms of radiation (e.g. infrared, gamma rays). The resulting atomic-scale details of the mineral give us the information from which we can understand aspects of how and at what conditions the mineral formed, and under what conditions it is stable. Why do minerals have the chemical formulae that they do? Why do they have their specific structural arrangements? Why are minerals stable over specific ranges of pH, Eh, temperature, pressure and constituent activities? What are the relations between crystal structure and enthalpy, entropy and Gibbs free energy of formation? How can we derive the atomic-scale mechanisms of geological processes? What is the relation of mathematical complexity to mineral structures and the behaviour of minerals in equilibrium and non-equilibrium processes? These questions are fundamental to Mineralogy itself and yet have been ignored in the past because they are not susceptible to established theoretical techniques in Physics and Chemistry. The work proposed here addresses several of these problems from a fundamental perspective, and will further our understanding of different Earth materials and the way that they respond to changes in their environment. A major part of this proposal involves the further development of a theoretical approach to answering these questions, an approach based on the topology (connectivity) of chemical bonds in space. I will use various aspects of Mathematics (Graph Theory, Combinatorial Topology, Complexity Theory) and Chemistry (the moments approach to the energy density-of-states of solids) to [1] develop connections between patterns of bond connectivity (bond topology) and their energetic content; [2] examine how these connections dictate the chemical compositions and structural connectivities of minerals; and [3] how these factors affect how minerals participate in geological processes. This theoretical work is supported by an extensive experimental program of mineral characterization involving amphiboles and tourmalines, gem minerals, TS-block minerals, new minerals, and other diverse projects that can benefit from our local experimental capabilities and theoretical expertise.

矿物是地球的基本材料，如果我们希望了解形成地球的过程，并继续改变地球的景观和人类环境，我们需要了解矿物在地球经历的全方位条件下的行为。地球。该提案重点关注各种矿物，试图了解影响其构成和行为的原子尺度因素，并利用这种理解在宏观尺度上合理化和预测其行为。我使用各种形式的辐射（X 射线、中子）通过衍射在原子尺度上“观察”矿物，并得出构成矿物的原子排列。有关原子无序的细节可以通过使用其他形式的辐射（例如红外线、伽马射线）的光谱来观察。由此产生的矿物原子级细节为我们提供了信息，我们可以从中了解矿物如何形成、在什么条件下形成以及在什么条件下稳定的各个方面。为什么矿物质有这样的化学式？为什么它们有其特定的结构安排？为什么矿物质在特定的 pH、Eh、温度、压力和成分活性范围内保持稳定？晶体结构与焓、熵和吉布斯形成自由能之间有什么关系？我们如何推导出地质过程的原子尺度机制？数学复杂性与矿物结构以及矿物在平衡和非平衡过程中的行为有何关系？这些问题是矿物学本身的基础，但在过去却被忽视，因为它们不易受到物理和化学中既定理论技术的影响。这里提出的工作从基本角度解决了其中几个问题，并将进一步我们对不同地球材料及其响应环境变化的方式的理解。该提案的主要部分涉及进一步发展回答这些问题的理论方法，一种基于空间化学键拓扑（连通性）的方法。我将使用数学（图论、组合拓扑、复杂性理论）和化学（固体能量态密度的矩方法）的各个方面来[1]开发键连接模式（键拓扑）和他们充满活力的内容； [2] 研究这些联系如何决定矿物的化学成分和结构连接性； [3]这些因素如何影响矿物参与地质过程的方式。这项理论工作得到了广泛的矿物表征实验计划的支持，涉及角闪石和电气石、宝石矿物、TS-块矿物、新矿物以及其他可以受益于我们当地实验能力和理论专业知识的不同项目。