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.

矿床是我们社会的金属来源，矿床的特征提供了有关其形成过程的关键信息。铁是一种金属，对发达国家的基础设施至关重要，对发展中国家至关重要，因为它是钢的主要成分。铁对于生产更可持续的基础设施也至关重要，包括风力涡轮机和电动汽车等技术。因此，更好地了解铁矿石矿床的形成方式和位置有助于提高社会进步的安全性。该项目将描述波多黎各的三个铁矿床，那里的铁矿床基本上尚未研究。由于这些沉积物在数千万年后相对不变，它们将提供对其形成过程的深入了解，这些过程通常由于广泛的变质和/或侵蚀而丢失。这项工作将提供至少10名本科生和4名研究生从奥本大学（Au）在亚拉巴马和波多黎各，马亚圭斯大学（RUM）在三年的实地和研究机会。来自这两所大学的学生将每月在波多黎各和Au的分析研讨会上亲自进行年度实地考察，培养一个名为AURUM的多元化实验室小组。建立和发展AURUM将培养不同的早期职业科学家之间的长期关系，为未来的合作和地球科学中代表性不足的人的成功奠定基础。在未来，这项研究将有助于告知当地管理决策有关这些资源。这项研究的科学目标是：1）详细描述波多黎各的矽卡岩矿床; 2）追踪金属迁移、流体流动事件和岩浆活动之间的时间和关系。矿床是地质过程和环境的最佳记录，但对这个岛上大多数矿床的详细研究从未发表过。特别是，几十年前，Tibes，Keystone和Island Queen铁矽卡岩被勘探和短暂开采。然而，这些潜在的经济存款没有被调查以来。这些地点为研究相对不受干扰的铁夕卡岩实例提供了独特的机会，因为它们没有经历过广泛的沉积后变质作用。研究目标将通过野外测绘、显微镜观察、磁铁矿微量元素和稳定同位素（铁、Fe;氧、O）地球化学、石榴石地球化学和地质年代学实现。该项目将进一步开发磁铁矿中Fe同位素比率和成对Fe-O同位素的使用，通过战略性地生成这三个非增生夕卡岩系统的数据，将其作为夕卡岩表征的工具。扩展现有的Fe-O数据库是建立Fe-O同位素系统学的关键一步，该系统学是矽卡岩研究和含磁铁矿矿床研究的有效工具。石榴石的地质年代学与映射的矿体将提供一个有效的成矿日期，而整个夕卡岩石榴石的地质年代学将限制夕卡岩形成流体事件的持续时间。石榴石地球化学与地质年代学相结合，将允许成矿与非成矿事件之间的时间和化学歧视。考虑到对波多黎各矿床的研究相对缺乏，以及详细研究非增生铁夕卡岩系统的机会，新数据将大大有助于了解铁矿床的形成地点和方式。&该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。