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: 2322205
• 负责人: Kimberly Lau
• 金额: $ 35.13万
• 依托单位: Pennsylvania State Univ University Park
• 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=2322205&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.

这项研究将调查海底（美国最重要的汇）贫氧条件下的铀（U）循环。提高我们对铀地球化学的理解对于岩石年龄测定、古环境重建、水等多种地质应用至关重要。质量，并确保新的关键矿物来源有助于将环境的演变与地球上以及潜在的系外行星上的生命进化联系起来。海洋中随时间变化的元素，例如铀和其他对氧含量敏感的元素，仍然具有挑战性，因为它们在低氧海洋环境中的行为尚不清楚，为了解决这一知识差距，该项目将跟踪新的铀物种的存在， U(+V)，并研究其在现代和古代海洋中的 U 循环中的作用，这些结果将为重建地球海洋和大气的氧气以及更广泛的全球 U 循环的宿主阶段和提供重要的见解。海洋环境中 U 的规范在很大程度上仍然存在未知，阻碍了我们重建沉积条件的能力。该项目将研究最重要的海洋汇中的 U 埋藏，以表征 U 形态、去除途径和全岩石 U 地球化学（包括其同位素组成）之间的关系。这一目标将会实现。包括：(1) 与海洋环境相关的 U 相实验；(2) 表征富含有机物页岩和沉积物中 U 形态与 U 地球化学之间的关系；(3) 开发解释模型以根据背景预测 U 地球化学除了研究生培训之外，该项目还将促进地球和环境科学专业的博物馆收藏和科学传播，以及宾夕法尼亚州和密歇根州农村地区 K-12 环境地球科学的推广。该奖项是 NSF 的法定使命，并被认为值得通过支持。使用基金会的智力价值和更广泛的影响审查标准进行评估。