Experimental Studies of Petrologic and Geochemical Kinetics

这个项目包括对地壳和上地幔在高压和高温下发生的化学现象进行实验研究。具体来说，这些实验旨在揭示低丰度化学元素及其同位素在地球上移动的机制和途径。目前正在研究三个具体的子课题：1)同位素质量对熔融岩石中原子或分子迁移速率的影响（强调气体形成元素S、C、H、O和Cl）；2)稀有气体（He、Ne、Xe）在地壳和上地幔关键矿物中的溶解度和迁移速率；3)地幔矿物颗粒边界中稀有金属元素（Pt、Au、Pd、W）的迁移速率和储量。这些研究的智力价值主要在于它们解决了地球物质的基本特性，这些特性为理解我们的星球及其子系统（地核、地幔、地壳和大气）的化学演化奠定了基础。例如，对挥发性元素流动性的质量效应可能导致火山喷发物与其“母体”岩浆之间迄今未预料到的同位素差异。稀有气体在深部矿物中的行为直接关系到地球上气体的储存和大气的演化。晶界中稀有金属原子的存在和迁移可能会影响地核-地幔分离模型以及地核和地幔在地质时期持续的化学“交流”。除了纯粹的科学价值之外，该项目更广泛的影响在于对研究生在高压高温材料科学实验的设计、执行和解释方面的教育和培训。在这一努力中获得的各种技能与人造材料和地球材料同样相关，并且所开发的技术可转移到高压和高温技术对材料合成或加工很重要的任何领域或应用中。

This project involves experimental investigations of chemical phenomena occurring at high pressures and temperatures in the Earth's crust and upper mantle. Specifically, the experiments are designed to shed light on the mechanisms and pathways by which low-abundance chemical elements and their isotopes move around in the Earth. Three specific sub-topics are being examined: 1) the effect of isotopic mass on the migration rates of atoms or molecules in molten rock (emphasizing the gas-forming elements S, C, H, O, and Cl); 2) the solubilities and migration rates of noble gases (He, Ne, Xe) in key minerals of the Earth's crust and upper mantle; and 3) the migration rates and storage of rare metallic elements (Pt, Au, Pd, W) in the boundaries between mineral grains of the Earth's mantle. The intellectual merit of these studies resides mainly in their addressing fundamental properties of Earth materials that serve as a basis for understanding the chemical evolution of our planet and its subsystems (core, mantle, crust and atmosphere). The mass effect on volatile-element mobility, for example, may lead to heretofore-unanticipated isotopic differences between volcanic emanations and their "parent" magmas. The behavior of noble gases in deep-seated minerals has a direct bearing on gas storage in the Earth and the evolution of the atmosphere. The presence and mobility of rare-metal atoms in grain boundaries could influence models of core-mantle separation and continued chemical "communication" between core and mantle over geologic time. Beyond the purely scientific merits, the broader impacts of this project lie in the education and training of graduate students in the design, execution and interpretation of experiments in high pressure-temperature materials science. The diverse skills gained in this endeavor are equally relevant to man-made materials as to those of the Earth, and the techniques developed are transferable to any field or application where the technology of high pressures and temperatures is important for materials synthesis or processing.