Experimental Investigation of Mineral-Fluid Equilibria at High Pressure

ManningEAR-0337170富水流体普遍存在于地壳深部和上地幔。由于矿物在这些环境中的溶解度很高，这种流体的释放和迁移会导致显著的传质。俯冲岩石圈产生的流体从板块中转移溶质，因此在地球化学循环中起着基础性的作用。捕虏体套装表明，上地幔的大部分区域可能被H2O-CO2-NaC l流体的通道所改变。在地壳变质过程中，富溶质流体可能对物质的重新分配起到至关重要的作用。要定量了解流体输送物质的过程，需要准确了解矿物的溶解度。在高压(5kbar)下，以前的实验挑战限制了关键数据的可获得性，然而，新的技术使得对重要的模型系统的研究成为可能。这个项目包括三组实验研究，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研究硅-聚合物的形成；(2)与钠长石-水系统的第二个临界终点有关的溶质化学变化的实验；以及(3)含挥发分相方解石和无水石相的溶解度表征。拟议研究的智力价值将是对高压下水物种化学的定量限制，而现有数据有限。这些数据对于理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。提出的钠长石-共晶石-石英实验是安廷加诺博士研究的一个组成部分。PI还包括来自加州大学洛杉矶分校岩石学研究的不同背景的本科生，导致在专业会议上发表摘要。

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.