Problems in Ore Metal Partitioning: Melt-Vapor-Brine Equilibria

矿石金属分配问题：熔体-蒸气-盐水平衡

• 批准号: 0738992
• 负责人: Philip Piccoli
• 金额: $ 37万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-15 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0738992&HistoricalAwards=false
• 关键词: Problems; Ore; Metal; Partitioning; Melt

Intellectual Merit. Prior experimental studies of melt-vapor-brine systems showed conclusively that copper partitions strongly in favor of a brine relative to a vapor. However, many studies of natural fluid inclusions from magmatic-hydrothermal ores and barren systems show the reverse behavior. This fundamental disagreement must be reconciled to arrive at realistic models for (1) formation of magmatic-hydrothermal ores; (2) the mobility of elements in the Earth's upper crust; and (3) exploration for the resources contained in magmatic-hydrothermal deposits. It is proposed to test experimentally the influences of various intensive parameters (including temperature and fugacities of O2, H2S, HCl, CO2 and other components) on Cu partitioning between vapor and coexisting brine. Experiments will be performed using cold-seal hydrothermal techniques, with vapor and brine phases trapped in situ in fractured quartz at run P&T. Cu, Ag, Zn and other cations will be analyzed in vapor and brine inclusions trapped in quartz (as well as coexisting the melt phase where present).Broader Impacts. Beyond the collection of important data on vapor+brine+/-melt equilibria, and the fundamentals of partitioning and element redistribution in the crust, these data will also serve as a basis for the construction of exploration models for porphyry and related deposits. The project will also support a mix of high school, undergraduate, masters and doctoral students. The graduate students are also involved in undergraduate teaching. Additionally, the PIs and students will highlight this research in campus outreach activities. Furthermore, the PIs actively participate in outreach in a variety of other formats (science lectures in a retirement community and a church group; Partners in Education Program (PEP) sponsored by GSA; training for the Ranger Interpreter Program in Yosemite National Park for the National Park Service; and visits to local Maryland elementary schools as part of the earth science curriculum).

智力优势。熔体-蒸汽-盐水系统的先前实验研究结论性地表明，铜分配强烈地有利于盐水相对于蒸汽。然而，许多来自岩浆热液矿石和贫瘠系统的天然流体包裹体研究显示相反的行为。必须调和这一根本性分歧，以便就下列问题建立现实的模型：（1）岩浆热液矿石的形成;（2）地球上地壳中元素的流动性;（3）岩浆热液矿床中所含资源的勘探。实验研究了温度和O2、H2S、HCl、CO2等组分的逸度对Cu在水蒸气和共存卤水之间分配的影响。实验将使用冷封水热技术进行，在运行P T时，将蒸汽相和盐水相原位捕获在断裂石英中。铜，银，锌和其他阳离子将被分析的蒸汽和盐水包裹体中捕获的石英（以及共存的熔体相，如果存在）。除了收集关于蒸汽+盐水+/-熔体平衡的重要数据以及地壳中分配和元素再分配的基本原理之外，这些数据还将作为构建斑岩和相关矿床勘探模型的基础。该项目还将支持高中生、本科生、硕士生和博士生。研究生也参与本科教学。此外，PI和学生将在校园外展活动中突出这项研究。此外，私人侦探还积极参与各种其他形式的外展活动（在退休社区和教会团体举办科学讲座; GSA赞助的教育伙伴计划（PEP）;为国家公园服务处在约塞米蒂国家公园举办护林员翻译计划培训;以及作为地球科学课程的一部分访问当地马里兰州小学）。