Phase Equilibria of Sulfur and Chlorine Bearing Phases in Magmas

建议研究开发含硫相和含氯相（气体、液体和固体）在熔融硅酸盐液体中的溶解度的热力学模型。重点将指向自然发生的“岩浆”成分的熔体。结果将被纳入软件包melt。所提出的硫模型将包括溶解熔体的还原和氧化形式，并将考虑与中间氧化态相关的溶解度最小值。它还将包括我们最近对硫化物液体在硅酸盐熔体中的溶解度的研究。最初的目标将是开发一个综合模型来预测硅酸盐熔体中硫的氧化状态，作为温度、体积组成和氧/硫逸度的函数。将在高温单大气气体混合炉中进行实验工作，以增加关于硫和氯溶解度关系的现有出版信息。与这些努力同时进行的是，一个初步的固体溶解液热力学模型将被开发出来，因为这些矿物代表了低硅活性岩浆中氯和硫的重要储集层。这项工作的应用将直接指向在地质温度和压力条件下阐明天然成分熔体中硫和氯的溶解度和相关系。

Ghiorso and KressEAR- 9980518Research is proposed to develop thermodynamic models for the solubility of sulfur- and chlorine-bearing phases (gasses, liquids and solids) in molten silicate liquids. Emphasis will be directed toward naturally occurring melts of "magmatic" compositions. Results will be incorporated into the software package MELTS. The proposed model for sulfur will include both the reduced and oxidized forms of dissolved melt species and will account for the solubility minimum associated with intermediate oxidation states. It will also incorporate our recent studies on the solubility of sulfide liquids in silicate melts. The initial goal will be development of a comprehensive model to predict the oxidation state of sulfur in silicate melt as a function of temperature, bulk composition, and oxygen/sulfur fugacity. Experimental work in high-temperature, one-atmosphere gas-mixing furnaces will be performed to augment existing published information on both sulfur and chlorine solubility relations. In parallel with these efforts, a preliminary thermodynamic model for solid solutions of the minerals sodalite, nosean, and hauyne will be developed, as these minerals represent important reservoirs of chlorine and sulfur in magmas of low silica activity. Applications of this work will be directed at illuminating sulfur and chlorine solubility and phase relations in natural composition melts under geologic temperature and pressure conditions.