Hydrous Magmatic Processes: An Experimental Study of Structure and Properties of Hydrous Silicate Melts, In-Situ, at High Pressure and Temperature

智力上的优点。 地球和类地行星的质量和能量转移过程涉及高温高压下的熔化和结晶。作为对我们理解这种岩浆过程的重要贡献，提出了一个研究计划：（1）在高压和高温下对含水硅酸盐熔体的结构进行原位实验研究，（2）确定熔体结构如何控制含水熔体的物理化学性质。这项研究的动机是几乎所有的岩浆过程都受到其H2O含量的强烈影响。水在硅酸盐熔体中的溶解机理的实验表征通常依赖于从作为硅酸盐熔体的代理的含水玻璃获得的数据。然而，含水熔体转变为含水玻璃引起结构变化。玻璃数据不能用于定量模拟含水熔体的物理化学性质。因此，在这项研究中，我们将确定二元金属氧化物-二氧化硅和三元金属氧化物-氧化铝-二氧化硅系统的水合熔体结构，而材料在高压和高温下。这些简单的模型系统将用于识别和分离控制结构和结构-性质关系的单个化学组分。结构研究将通过拉曼和傅里叶变换红外光谱的含水熔体在一个水热金刚石对顶砧单元操作在25- 1000 C和0.1MP-1.5 GPa的温度和压力范围内，分别进行。熔融数据将通过使用拉曼、FTIR和NMR光谱方法测定含水玻璃结构来增强。熔体及其玻璃的结构分析也将有助于我们理解玻璃形成过程，并提供信息，以评估硅酸盐玻璃结构在多大程度上可以用作熔体结构的代表。更广泛的影响。该研究计划将涉及，平均1-2博士后研究人员和2名本科生和高中生在整个3年的拟议研究期间。学生和博士后将参与实验项目的执行，并将实验结果应用于岩石形成过程的表征。此外，继续和扩大PI与地球内部研究所（ISEI，Misasa，日本）和地球仪研究所（巴黎，法国）的研究人员之间的国际合作将进一步帮助拟议的研究计划。

Intellectual merit. Mass and energy transfer processes in the Earth and terrestrial planets involve melting and crystallization at high temperature and pressure. As an important contribution to our understanding of such magmatic processes, a research program is proposed (1) to conduct an experimental study, in-situ, at high pressures and temperatures of the structure of hydrous silicate melts, and (2) to determine of how melt structure governs physicochemical properties of hydrous melts. The research is motivated by the fact nearly all magmatic processes are strongly affected by their H2O content. Experimental characterization of solution mechanisms of H2O in silicate melts commonly relies on data obtained from hydrous glasses serving as proxies for silicate melts. However, transformation of hydrous melts to hydrous glasses causes structural changes. The glass data cannot be used for quantitative modeling of physicochemical properties of hydrous melts. In this study, we will, therefore, determine hydrous melt structure of binary metal oxide-silica and ternary metal oxide-alumina-silica systems while the materials are at high pressure and temperature. These simple model systems will be used in order to identify and isolate individual chemical components governing structure and structure-property relationships. Structural studies will be conducted via Raman and FTIR spectroscopy of hydrous melts in a hydrothermal diamond anvil cell operating in the 25-1000C and 0.1MP-1.5 GPa temperature, and pressure ranges, respectively. The melt data will be augmented by determination of hydrous glass structure using Raman, FTIR, and NMR spectroscopic methods. Structure analysis of melts and their glasses will also contribute to our understanding of glass-forming processes and provide information to assess the extent to which silicate glass structure can be used as a proxy for melt structure. Broader impacts. The research program will involve, on average, 1-2 post-doctoral researchers and 2 undergraduate and high school students throughout the 3-year period of the proposed research. The students and post-docs will be involved in execution of experimental projects and in the application of the experimental results to characterization of rock-forming processes. In addition, continuing and expanding international collaboration between the PI and researchers from the Institute for the Study of the Earth''s Interior (ISEI, Misasa, JAPAN) and Institut de Physique du Globe (Paris, FRANCE) will further aid the proposed research program.