Ore Metals in Magmatic Systems

“该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。“智力优点：拟议中的研究旨在填补关键的空白，我们的知识有关的岩浆分配硫化物，Fe-（Cu）-S-O熔体，并选择氧化物和硅酸盐之间的选定元素。在岩浆热液矿床中，这些元素可分为两个重要的组：Mo-W组和Cu-Ag-Au组。该项目建立在以前的工作上的矿物/熔体分配系数的实验测定长英质熔体-蒸汽-卤水-氧化物-磁黄铁矿系统中的许多矿石和相关元素，通过研究分配的Mo，W，Ag和Au之间的熔体，硫化物，氧化物，硅酸盐矿物在指定的，低方差的条件下。详细地说，这项工作包括：[1]综合评价硫和氧逸度对岩浆阶段之间矿石金属分配的影响; [2]对选定元素进行LA-ICP-MS分析（其中许多在过去很难研究）;[3]扩大矿物/熔体对的研究范围，包括造岩硅酸盐。新的和以前收集的分区数据将被用来定量评估有关岩浆过程，有助于矿石金属的多样性在岩浆热液矿床的竞争假说。这些模型所需的重要参数是估算在岩浆到达地壳浅层之前因结晶而损失的金属比例。更广泛的影响：除了收集有关矿石金属分配的重要数据及其在地壳中重新分布的基本原理之外，这些数据还将作为构建斑岩矿床勘探模型的基础。该研究小组有一个良好的记录，涉及高中，本科，硕士和博士生的混合在积极的研究。所有研究生都参与本科教学。此外，教师和学生参加，并突出他们的研究在马里兰州日（每年四月举行）;校园吸引了约70，000游客平均为这个事件。此外，私人侦探还积极参与各种形式的外展活动（在退休社区和教会团体举办科学讲座;由GSA赞助的教育伙伴方案;为国家公园服务处在约塞米蒂国家公园举办护林员口译员方案培训;作为地球科学课程的一部分访问当地马里兰州小学;以及为当地宝石和宝石协会举办讲座）。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Intellectual Merit: The proposed research is designed to fill critical gaps in our knowledge concerning the magmatic partitioning of selected elements among sulfides, Fe-(Cu)-S-O melts, and selected oxides and silicates. These elements fall into two important groups found in magmatic-hydrothermal ore deposits: the Mo-W group, and the Cu-Ag-Au group. This project builds on previous work on the experimental determination of the mineral/melt partition coefficients of many ore and related elements in felsic melt - vapor - brine - oxide - pyrrhotite systems by studying the partitioning of Mo, W, Ag and Au among melts, sulfides, oxides, and silicate minerals under well specified, low-variance conditions. In detail, this work involves: [1] Comprehensive evaluation of the effects of sulfur and oxygen fugacity on ore metal partitioning among magmatic phases; [2] LA-ICP-MS analysis of selected elements (many of which were difficult to study in the past); and [3] Expand the range of mineral/melt pairs to be investigated to include rock-forming silicates. New and previously collected partitioning data will be used to quantitatively evaluate competing hypotheses regarding magmatic processes that contribute to ore metal diversity in magmatic-hydrothermal deposits. Important parameters needed for such models are estimates of the proportion of metals lost to crystallization before magmas reach shallow crustal depths.Broader Impacts: Beyond the collection of important data on ore metal partitioning, and the fundamentals of their redistribution in the crust, these data will also serve as a basis for the construction of exploration models for porphyry deposits. The research group has an excellent track record of involving a mix of high school, undergraduate, masters and doctoral students in active research. All graduate students are involved in undergraduate teaching. Additionally, faculty and students participate in, and highlight their research in Maryland Day (held in April each year); the campus attracts an average of some 70,000 visitors for this event. Furthermore, the PIs actively participate in outreach in a variety of 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; visits to local Maryland elementary schools as part of the earth science curriculum; and lectures to local gem and lapidary societies).