Molybdenum Isotope Geochemistry in Marine Sediments II: Experimental Determinations of Mo Isotope Fractionation Under Sulfidic Conditions

海洋沉积物中钼同位素地球化学 II：硫化物条件下钼同位素分馏的实验测定

• 批准号: 0727102
• 负责人: James McManus
• 金额: --
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0727102&HistoricalAwards=false
• 关键词: Molybdenum; Isotope; Geochemistry; Marine; Sediments

Transition elements play an essential role in the marine carbon and oxygen cycles, particularly because their stable isotopes offer significant potential for tracing or quantifying past and present chemical processes in the ocean. Molybdenum (Mo), whose marine geochemistry is dominated by the formation of various isotopic signatures, indicates significant potential as a paleoredox indicator.Laboratory experiments quantifying Mo fractionation in oxic environments have been carried out; however, Mo fractionation under reducing conditions have not been empirically investigated. A scientist from Oregon State University proposes a series of experiments to determine the geochemical mechanisms responsible for fractionating Mo isotopes in sulfidic marine environments. It is hypothesized that Mo isotope compositions in reducing continental margin marine sediments are controlled by Mo-sulfide adsorption to pyrite. To test the hypothesis, a suite of experiments would be done to measure sulfide-controlled Mo isotope fractionation. Achieving a quantitative understanding of Mo isotope behavior is needed for interpretating Mo isotope variations in the marine sediment record.In terms of the broader impacts, the principal investigator plans to collaborate with a scientist at Newcastle University. One high school student and one graduate student would be supported and trained as part of this project.

过渡元素在海洋碳和氧气周期中起着至关重要的作用，尤其是因为它们的稳定同位素为追踪或量化过去和现在的化学过程提供了重要潜力。钼（MO）的海洋地球化学以各种同位素特征的形成主导，表明作为paleodox指标的巨大潜力。实验室实验量化了量化MO分馏的质量分馏。但是，在还原条件下的MO分馏尚未经过经验研究。 俄勒冈州立大学的一名科学家提出了一系列实验，以确定负责分割硫磺海洋环境中MO同位素的地球化学机制。 假设MO同位素组成在减少大陆缘海洋沉积物中的Mo硫化物吸附到黄铁矿中受到控制。 为了检验假设，将进行一套实验，以测量硫化物控制的MO同位素分馏。 需要对MO同位素行为进行定量理解，以解释海洋沉积物记录中的MO同位素变化。根据更广泛的影响，主要研究人员计划与纽卡斯尔大学的一位科学家合作。 作为该项目的一部分，将为一名高中生和一名研究生提供支持和培训。