Collaborative Research: Characterizing Iron Deposits in Puerto Rico to Elucidate Metal Transport and Magnetite Mineralization Processes in Skarn Systems

合作研究：表征波多黎各铁矿床以阐明矽卡岩系统中的金属迁移和磁铁矿成矿过程

• 批准号: 2217928
• 负责人: Thomas Hudgins
• 金额: $ 24.84万
• 依托单位: University of Puerto Rico Mayaguez
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2217928&HistoricalAwards=false
• 关键词: Collaborative; Research; Characterizing; Iron; Deposits

Characterizing ore deposits, the sources of metal for our society, provides key information about the processes related to their formation. Iron is a metal that is vital for the infrastructure of developed countries and essential for those that are developing as it is the primary component of steel. Iron is also critical for the production of a more sustainable infrastructure that includes technologies such as wind turbines and electric cars. Therefore, an improved understanding of how and where iron ore deposits form works toward increased security for societal progress. This project will characterize three iron ore deposits in Puerto Rico, where ore deposits have remained largely unstudied. As these deposits are relatively unchanged after tens of millions of years, they will provide insight into the processes involved in their formation, which are generally lost due to extensive metamorphism and/or erosion. This work will provide field and research opportunities for at least ten undergraduate and four graduate students from Auburn University (AU) in Alabama and the University of Puerto Rico, Mayagüez (RUM) over three years. Students from these two universities will unite virtually on a monthly basis and in person for annual field seasons in Puerto Rico and analytical workshops at AU, fostering a diverse lab group called AURUM. Establishing and growing AURUM will cultivate long-lasting relationships between diverse early career scientists, setting the foundation for future collaborations and success of persons underrepresented in Geoscience. In the future, this research will help inform local management decisions related to these resources. The scientific goals of this study are: 1) to characterize in detail the iron skarn deposits of Puerto Rico; 2) to track the timing and relationship between metal transport, fluid flow events, and magmatic activity. Ore deposits are excellent records of geologic processes and environments, yet detailed studies of most deposits on this island have never been published. In particular, the Tibes, Keystone, and Island Queen iron skarns were prospected and briefly mined decades ago. However, these potentially economic deposits have not been investigated since. These sites present a unique opportunity to study relatively undisturbed iron skarn examples because they have not experienced extensive post-depositional metamorphism. The research goals will be achieved through field mapping, microscopic observations, magnetite trace element and stable isotope (iron, Fe; oxygen, O) geochemistry, and garnet geochemistry and geochronology at each site. This project will further develop the use of Fe isotope ratios and paired Fe-O isotopes in magnetite as tools in skarn characterization by strategically generating data in these three unaccreted skarn systems. Expanding the existing Fe-O database is a critical step in establishing Fe-O isotope systematics as an effective tool in skarn research and magnetite-bearing deposits in general. Geochronology of garnets associated with the mapped ore bodies will provide an effective date for ore formation, while the geochronology of garnets throughout the skarn will constrain the duration of skarn-forming fluid events. Garnet geochemistry coupled with geochronology will allow for temporal and chemical discrimination between ore-forming versus non-ore-forming events. Considering the relative lack of research on the ore deposits of Puerto Rico and the opportunity to study in detail unaccreted iron skarn systems, the new data will contribute significantly to foundational knowledge on where and how iron ore deposits form.This project is jointly funded by the Petrology & Geochemistry Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

对矿床（我们社会的金属来源）进行表征，提供了与其形成相关的过程的关键信息。铁是一种对发达国家的基础设施至关重要的金属，对于发展中国家的基础设施也至关重要，因为它是基础设施的主要组成部分。钢铁对于生产更可持续的基础设施（包括风力涡轮机和电动汽车）也至关重要。因此，更好地了解铁矿石矿藏的形成方式和地点有助于提高社会进步的安全性。波多黎各的三个铁矿床，由于这些矿床在数千万年之后相对没有变化，因此它们将提供对其形成过程的深入了解，而这些过程通常由于广泛的变质作用和/或侵蚀而消失。三年内，为来自阿拉巴马州奥本大学 (AU) 和波多黎各大学马亚圭斯分校 (RUM) 的至少 10 名本科生和 4 名研究生提供研究机会，这两所大学的学生将每月进行虚拟和面对面的交流。每年野外季节AURUM 的建立和发展将在不同的早期职业科学家之间培养持久的关系，为未来在地球科学领域的合作和成功奠定基础。 ，这项研究将有助于为与这些资源相关的当地管理决策提供信息。这项研究的科学目标是：1）详细描述波多黎各铁矽卡岩矿床的特征；2）跟踪金属运输、流体之间的时间和关系。矿床是地质过程和环境的优秀记录，但对该岛上大多数矿床的详细研究从未发表过，特别是对蒂布斯、基斯通和岛皇后铁矽卡岩进行了勘探和短暂开采。然而，自从几十年前以来，这些潜在的经济矿床就没有被研究过，因为它们没有经历过广泛的沉积后变质作用。该项目将通过每个地点的现场测绘、显微观察、磁铁矿微量元素和稳定同位素（铁、Fe；氧，O）地球化学以及石榴石地球化学和地质年代学来进一步开发铁同位素比和配对铁氧的使用。通过战略性地在这三个非凝固矽卡岩系统中生成数据，将磁铁矿中的同位素作为矽卡岩表征的工具是关键的一步。建立铁氧同位素系统学作为夕卡岩研究和一般含磁铁矿矿床的有效工具，与绘制的矿体有关的石榴石地质年代学将为矿石形成提供有效的日期，而整个夕卡岩中石榴石的地质年代学将受到限制。形成矽卡岩的流体事件的持续时间与地质年代学相结合将允许在成矿与成矿之间进行时间和化学区分。考虑到对波多黎各矿床的研究相对缺乏以及详细研究未增生铁矽卡岩系统的机会，新数据将极大地有助于了解铁矿床形成地点和方式的基础知识。该项目由岩石学与地球化学计划和刺激竞争性研究既定计划 (EPSCoR) 联合资助。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。