Experimental Study of HC1 in Magmatic-Hydrothermal Systems

矿床及相关矿物蚀变常与富硅火成岩相联系。这些火成岩侵入体被假设演化出一个或多个富水和富氯流体相，这些流体相有助于矿物蚀变和附近的矿床沉积。该岩浆挥发相中的盐酸（HCl）浓度已被证明会影响矿物的稳定性、金属的行为和矿石的沉淀机制。HCl对这些过程的影响程度尚不清楚，因为缺乏实验数据来检验目前关于挥发相影响矿物蚀变和金属运输程度的假设。将进行一系列的实验来解决这一基本知识的缺乏。本研究将研究岩浆热液系统在600-750℃的压力和温度下HCl的活性，在那里金属从结晶的石英熔体中分离出来并沉积在系统的高温部分。此外，拟议的研究将收集有关HCl在高盐度盐水和超临界流体中选择矿物系统的活性的重要数据。我们的研究将在温度为600-750C和50-140 MPa的蒸汽不饱和盐水和超临界流体相场的盐度范围内共同解决这些系统，并应用于更广泛的岩浆热液系统。一名本科生和一名研究生将参与本研究项目，并将接受实验地质学、热力学和地球化学方面的培训。研究生也将指导参与这个项目的初级成员。该研究成果可为改进现有高温矿床金属勘查模式提供直接的经济效益。

Ore deposits and related mineral alteration are often associated with silica-rich igneous rocks. These igneous intrusions have been hypothesized to evolve one or more water and chlorine-rich fluid phases, which contribute to mineral alteration and nearby ore deposition. The hydrochloric acid (HCl) concentration within this magmatic volatile phase has been shown to influence mineral stability, the behavior of metals and the mechanisms of ore precipitation. The extent to which HCl influences these processes is unknown because there is a dearth of experimental data with which to test current hypotheses on the extent to which volatile phases influence mineral alteration and metal transport. A succession of experiments will be conducted to address this lack of fundamental knowledge. This study will examine the activity of HCl at pressures and temperatures of the magmatic-hydrothermal system, 600-750C, where metals are partitioned from a crystallizing felsic melt and deposited in the high-temperature portion of the system. Additionally, the proposed research will compile important data regarding the activity of HCl in both high-salinity brines and supercritical fluids in select mineral systems. Our study will address these systems collectively over a range of salinities within the vapor-undersaturated brine and supercritical fluid phase fields at temperatures from 600-750C and 50-140 MPa with applications to the broader magmatic-hydrothermal system. An undergraduate student and a graduate student will participate in this research project and will be trained in experimental geology, thermodynamics, and geochemistry. The graduate students will also mentor the more junior members involved in this project. The results of this research can provide direct economic benefits by improving existing metal exploration models associated with high-temperature ore deposits.