Isotope Fractionation During Multicomponent Diffusion in Molten Basalts

熔融玄武岩多组分扩散过程中的同位素分馏

基本信息

批准号：
2020603
负责人：
Youxue Zhang
金额：
$ 37.22万
依托单位：
Regents of the University of Michigan - Ann Arbor
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2020603&HistoricalAwards=false
关键词：
Isotope Fractionation During Multicomponent Diffusion

项目摘要

Isotope ratios in nature can change during equilibrium or kinetic processes because different isotopes of the same element have slightly different physical and chemical properties. Isotope fractionation during diffusion is a fundamental process with multiple applications, including development of methods for separation of isotopes, correction for isotope ratios in isotope age determination, examination of atomic scale processes of diffusion, and inference of history and rate of rock formation. This project will investigate isotope fractionation during multicomponent diffusion in molten basalts with natural isotope compositions. Specifically, diffusive isotope fractionation of three major elements in rocks, K, Ti, and Mg, will be evaluated. The project will provide a research opportunity for a graduate student. New methodologies and analytical protocols will be developed that will be useful to many other researchers. Isotope ratios of K, Ti ad Mg in existing well-characterized experimental charges will be measured by pushing the limits of current SIMS instruments to resolve the isotope ratio variation in the quenched glass. The isotope data to be acquired will ultimately enable researchers to understand diffusion mechanisms at the fundamental molecular and ionic level. The project will also advance the SIMS technique for isotope ratio measurements and will have applications to isotope fractionation during natural processes of magma mixing as well as mineral dissolution and growth. This work will contribute to the fundamental understanding of diffusion and isotope fractionation in mafic silicate melts. In addition, the results can be applied to understand magma mixing and mineral growth, and to infer cooling time scales of rocks. Graduate students will be trained and will attend scientific meetings.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.

自然界中的同位素比在平衡或动力学过程中会发生变化，因为同一元素的不同同位素具有略有不同的物理和化学特性。扩散过程中的同位素分馏是具有多种应用的基本过程，包括开发同位素分离的方法，同位素年龄确定中同位素比的校正，检查扩散的原子量表过程以及岩石形成的历史和速率的推理和速率。该项目将研究具有天然同位素组成的熔融玄武岩的多组分扩散期间的同位素分馏。具体而言，将评估岩石，K，Ti和Mg中三个主要元素的扩散同位素分馏。该项目将为研究生提供研究机会。将开发新的方法论和分析方案，这对许多其他研究人员都会有用。在现有良好表征实验指控中K，TI AD MG的同位素比通过推动当前的SIMS仪器的限制来解决淬灭玻璃中的同位素比变化。要获得的同位素数据最终将使研究人员能够理解基本分子和离子水平的扩散机制。该项目还将推进同位素比率测量的SIMS技术，并在岩浆混合的自然过程以及矿物质溶解和生长期间对同位素分馏应用。这项工作将有助于对镁铁质硅酸盐融化的扩散和同位素分馏的基本理解。此外，结果可以应用于了解岩浆混合和矿物质的生长，并推断岩石的冷却时间尺度。研究生将接受培训，并将参加科学会议。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评论标准来评估值得支持的。