CAREER: Did Carlin-type Gold Come From Magmas?

美国近80%的黄金产自北方内华达州的卡林型金矿。尽管这些矿床已有50多年的生产历史和巨大的经济重要性，但其成因仍有争议。一些研究人员认为，黄金一定来自地壳浅层的岩浆，而另一些人则认为，黄金已经存在于沉积宿主岩石中，岩浆作用并不是创造黄金经济浓度的必要条件。该项目解决了科学争议，旨在通过更好地了解卡林型金矿的形成来促进勘探工作。特别是在内华达州多产的卡林趋势，许多研究试图将黄金与始新世岩浆联系起来;尽管数据是允许的，但明确的证据仍然难以捉摸。该项目采取了一种新的方法，重点放在北方巴特尔山区，那里有卡林型金矿、斑岩和矽卡岩矿床，已知这些矿床是岩浆成因的，还有远距离浸染型矿床，具有所有这些存款类型的混合特征。为了确定远距离浸染型矿床是否将卡林型金矿与成因岩浆侵入体联系起来，本项目将确定矿石流体的性质和邻近金矿的成矿时间。除了填补经济地质学方面的长期知识空白外，这项工作还有助于推动更广泛的地球科学举措，以确定地壳中岩浆活动和金属流动的特征。尽管采矿对国家安全至关重要，而且采矿所处的环境和社会框架日益复杂，但美国在这一领域缺乏熟练劳动力。该项目整合了矿床的教学和研究，以开发创新的课程，将招募和留住学生的教育途径，导致职业生涯的采矿。项目科学将被纳入科罗拉多矿业学院的研究生实地课程和本科生案例研究模块，以及与接力教育研究生院和科罗拉多矿业协会合作举办的K-12教师培训研讨会。除了作为两个博士论文的基础，5年的项目将达到50名研究生，150名本科生，25+科学教师和600+ K-12学生。

Nearly 80% of the gold produced in the United States comes from northern Nevada's Carlin-type gold deposits. Despite more than 50 years of production and the great economic importance of these deposits, their genesis is debated. Some researchers argue that the gold must have come from magmas emplaced in the shallow crust, while others propose that the gold was already present in the sedimentary host rocks and magmatism was not necessary to create economic concentrations of gold. This project addresses the scientific controversy and aims to facilitate exploration efforts through improved understanding of how Carlin-type gold deposits formed. Particularly in Nevada's prolific Carlin trend, many studies have attempted to link the gold to Eocene magmas; although the data are permissive, unequivocal evidence remains elusive. This project takes a new approach by focusing on the northern Battle Mountain district, where there is Carlin-type gold, porphyry and skarn deposits that are known to have a magmatic origin, and distal disseminated deposits bearing hybrid characteristics of all of those deposit styles. In order to determine whether the distal disseminated deposits link the Carlin-type gold to causative magmatic intrusions, this project will characterize the nature of the ore fluids and the timing of mineralization at adjacent gold deposits. In addition to addressing a long-standing knowledge gap in economic geology, this work contributes towards advancing broader geoscience initiatives to characterize magmatism and metal flux in the crust. Despite the critical importance of mining to national security and the increasingly complex environmental and social framework in which mining occurs, the United States has a shortage of skilled labor in this sector. This project integrates teaching and research on ore deposits to develop innovative curricula that will recruit and retain students in educational pathways leading to careers in mining. The project science will be incorporated into a graduate field course and undergraduate case study modules at Colorado School of Mines, and a K-12 teacher training workshop conducted in collaboration with Relay Graduate School of Education and the Colorado Mining Association. In addition to serving as the basis for two PhD dissertations, the 5-year project will reach 50 graduate students, 150 undergraduate students, 25+ science teachers, and 600+ K-12 students.