Experimental Investigation of Mineral-Fluid Equilibria at High Pressure

ManningEAR-0337170富含水的流体在地壳深处和上地幔中很常见。由于矿物在这些环境中的溶解度很高，因此此类流体的释放和迁移会导致显着的传质。俯冲岩石圈产生的流体从板块转移溶质，因此在调节地球化学循环中发挥着重要作用。包体套件表明，上地幔的重要区域可能会因 H2O-CO2-NaCl 流体的通过而发生改变。在地壳变质作用过程中，富含溶质的流体可能在物质重新分布中发挥至关重要的作用。要定量了解流体输送物质的过程，需要准确了解矿物溶解度。在高压（5 kbar）下，实验挑战此前限制了关键数据的可用性；然而，现在新技术使得对重要模型系统进行研究成为可能。该项目涉及三组实验研究，旨在更好地了解高压矿物流体平衡：（1）在广泛的压力和温度范围内二氧化硅聚合物形成的研究； (2)钠长石-水系统中与第二个关键终点相关的溶质化学变化的实验； (3) 挥发性相方解石和硬石膏的溶解度表征。拟议研究的智力价值将是对高压下水性物质的化学性质的定量限制，而现有数据有限。这些数据对于了解流体如何参与地球的物质循环至关重要。更广泛的影响将包括学生培训和指导。拟议的钠长石-钠长石-石英实验是博士论文的一部分。 A. Antingano 的研究。 PI 还包括加州大学洛杉矶分校岩石学研究领域不同背景的本科生，并在专业会议上发表了摘要。

ManningEAR-0337170Water-rich fluids are common in the deep crust and upper mantle. Because mineral solubilities are high in these environments, liberation and migration of such fluids causes significant mass transfer. Fluids generated by subducting lithosphere transfer solutes from the slab and therefore play a fundamental role in mediating chemical cycling in the Earth. Xenolith suites show that significant regions of the upper mantle may be modified by passage of H2O-CO2-NaCl fluids. During crustal metamorphism, solute-rich fluids may play a crucial role in the redistributing matter. Quantitative understanding of the processes by which fluids transport material requires accurate knowledge of mineral solubility. At high pressures (5 kbar), experimental challenges have previously limited the availability of key data; however, new techniques now make it possible to carry out studies on important model systems.This project involves three sets of experimental studies of aimed at better understanding high-pressure mineral-fluid equilibria: (1) studies of silica-polymer formation over a broad range of pressure and temperature; (2) experiments on the changes in solute chemistry associated with the second critical end-point in the system albite-water; and (3) characterization of the solubility of the volatile-bearing phases calcite and anhydrite.The intellectual merit of the proposed investigation will be quantitative constraints on the chemistry of aqueous species at high pressure, where existing data are limited. Such data are critical for understanding how fluids participate in the material cycling in the Earth. Broader impacts will include student training and mentoring. The proposed experiments on albite- paragonite-quartz are a component of Ph.D. studies of A. Antingano. The PI has also included undergraduates from diverse backgrounds in petrologic research at UCLA, resulting in published abstracts at professional meetings.