Collaborative Research: Determining the role of uranium(V) in the global uranium cycle by characterizing burial mechanisms in marine sinks

合作研究：通过表征海洋汇埋藏机制确定铀（V）在全球铀循环中的作用

• 批准号: 2322206
• 负责人: Anthony Chappaz
• 金额: $ 34.86万
• 依托单位: Central Michigan University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-05-15 至 2027-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2322206&HistoricalAwards=false
• 关键词: Collaborative; Research; Determining; role; uranium

This study will investigate uranium (U) cycling in oxygen-depleted conditions on the ocean floor, the most important sink of U. Improving our understanding of U geochemistry is critical for geological applications as diverse as dating the age of rocks, paleoenvironmental reconstruction, water quality, and securing new critical mineral sources. Reconstructing the oxygen levels of ancient oceans helps to link the evolution of the environment with evolution of life on Earth and potentially on exoplanets. Interpreting tools to probe oxygen levels in the oceans through time, such as U and other elements sensitive to oxygen level, remain challenging because of the unknowns about how they behave in low-oxygen marine settings. To address this knowledge gap, this project will track the presence of a new U species, U(+V), and investigate its role in the U cycle in modern and ancient oceans. These results will provide important insights for reconstructions of oxygen of Earth’s oceans and atmosphere, as well as the global U cycle more broadly. The host phases and speciation of U in marine settings remain largely unknown, hampering our ability to reconstruct depositional conditions. This project will investigate U burial in the most significant marine sink to characterize the relationship between U speciation, removal pathways, and whole-rock U geochemistry, including its isotope composition. This goal will be accomplished with: (1) experiments of U phases relevant to marine settings; (2) characterizing the relationship between U speciation and U geochemistry in organic-rich shales and sediments; and (3) developing an interpretive model to predict U geochemistry from contextual information. In addition to graduate training, this project will promote museum collections and science communication for Earth and environmental science majors and K-12 outreach in environmental geosciences in rural Pennsylvania and Michigan.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.

这项研究将研究铀（U）在海底氧气耗尽条件下的铀（U）循环，这是U的最重要的水槽。提高我们对U地球化学的理解，对于地质应用，作为岩石时代，古环境重建，水质，水质，水质，并确保新的关键矿物质的时代至关重要。重建古老海洋的氧气水平有助于将环境的演变与地球上的生命进化联系起来，并有可能在外部球队上。解释工具以随着时间的流逝探测海洋中的氧气水平，例如U和对氧气敏感的其他元素，由于对它们在低氧海洋环境中的表现未知，因此仍然是挑战。为了解决这个知识差距，该项目将跟踪新的U物种U（+V）的存在，并研究其在现代和古老海洋中U周期中的作用。这些结果将为重建地球海洋和大气的氧以及全球U周期的重建提供重要见解。在海洋环境中，U的宿主阶段和规范在很大程度上未知，从而阻碍了我们重建沉积条件的能力。该项目将调查U葬在最重要的海洋水槽中，以表征U规格，去除途径和全岩U地球化学（包括其同位素组成）之间的关系。该目标将通过：（1）与海洋环境相关的U阶段的实验； （2）表征有机色的阴影和沉积物中U物种形成与地球化学之间的关系； （3）开发一种解释性模型，从上下文信息中预测地球化学。除研究生培训外，该项目还将促进宾夕法尼亚州农村和密歇根州环境地球科学的地球和环境科学专业的博物馆馆藏和科学传播。该奖项反映了NSF的法定任务，并通过评估该基金会的智力功能和广泛的影响来评估NSF的法定任务。