Stable Isotope Constraints on Source, Contamination, and Alteration of Great Basin Igneous Rocks, and Implications for Metallogeny

ArehartCarlin型矿床是北美最丰富和最重要的热液金矿床之一，似乎在时间和空间上与始新世岩浆活动有关。 相比之下，较老的岩浆事件似乎没有产生类似的存款。 为了更好地了解上升岩浆（这些热液系统的驱动力）与岩浆所通过的地壳岩石之间的相互作用，将对大盆地中未蚀变的深成岩进行硫和氧稳定同位素的测量。 这些测量结果将与可能为这些火成岩提供成分的地壳（晚元古代裂谷充填沉积岩、晚元古代沉积岩）和地幔物质的类似同位素测量结果进行比较。 这些数据与现存的地质、地球化学和地球物理数据相结合，将用于阐明该地区的地壳结构，了解其对巨型热液系统发展的控制。 这些数据还将解决为什么不同年龄的岩浆活动，但在同一地区，显然没有产生相同的大规模金属再分配在地壳中发生在始新世的问题。拟议的研究将提供机会，专注于发展事业的学生在矿床研究。 由行业和政府支持的应用科学的结合将使学生接触到矿物存款研究的多个方面，并在培训即将到来的一代矿物地球科学家在工业，学术界或政府的职位至关重要。 对这项研究的支持将有助于维持和加强研究和教育的基础设施，包括内华达州稳定同位素实验室

EAR-0309935ArehartCarlin-type deposits are amongst the richest and most important hydrothermal gold deposits in North America and appear to be associated in time and space with Eocene magmatism. In contrast, older magmatic episodes do not appear to have generated similar deposits. To better understand the interaction of ascending magmas, which were the driving force for these hydrothermal systems, with crustal rocks through which the magmas passed, measurements of stable isotopes of sulfur and oxygen will be made of unaltered plutonic rocks in the Great Basin. These measurements will be compared to similar isotopic measurements of crustal (cratonic basement, late Proterozoic rift-filling sedimentary rocks, Phanerozoic sedimentary rocks) and mantle materials that could have provided components to these igneous rocks. These data, when combined with extant geological, geochemical and geophysical data, will then be used to elucidate the crustal architecture of the region, to understand its control on the development of giant hydrothermal systems. These data will also address the question of why magmatism of different ages but in the same region, apparently did not generate the same large-scale metal redistribution in the crust that occurred in the Eocene.The proposed research will provide opportunities to students focused on developing careers in mineral deposits research . The combination of applied science supported by both industry and government will provide students exposure to multiple aspects of mineral deposit research, and is critical in training the upcoming generation of mineral geoscientists for positions in industry, academia, or government. Support for this research will help to maintain and enhance the infrastructure for research and education, including the Nevada Stable Isotope Laboratory