Collaborative Research: Stable strontium isotope ratios (88/86Sr) in abiotic and microbially mediated barite

拟议中的研究结果将对重晶石进行新的同位素测量，重晶石是一种高度稳定且广泛分布的矿物，存在于所有年龄的岩浆岩、变质岩和沉积岩中，以及土壤、气溶胶尘埃和地外物质中。建立重晶石稳定锶同位素分馏的控制参数，将为地质环境研究开辟一条新的途径，包括地球化学、水文地质、热液和古环境研究。这项基础性研究将为今后利用重晶石中质量相关的锶同位素进行地球科学研究奠定基础。重晶石可能是一个理想的工具来解决地球科学中的关键问题，包括早期地球生物地球化学，地外样品中潜在生命的证据，重建地层流体(如泉水和渗漏)中的温度，水-岩相互作用，追踪大气输入土壤的来源，以及重建地球期间全球锶预算的变化？S过去。世界上很少有实验室开发出测量稳定的锶同位素比率的方法；而这里提出的这个新的稳定同位素系统的工作将提供一个独特的机会，在开始阶段为这个新的同位素系统的发展做出贡献。研究生和本科生将有机会在多个实验室(肯特州立大学、南加州大学、肯特州立大学)就这一研究项目进行工作和互动。加州大学洛杉矶分校阿克伦分校俄克拉何马州)，从而发展和指导研究和分析技能。他们将进行仔细的实验，在俄克拉荷马州西部一个既定的田野地点收集样本，并与参与该项目的学生以及科罗拉多州西部和犹他州北部的田野地点互动。当地高中的外展活动将通过出版的实践学习模块来建立，该模块调查温室效应的基本概念。并将雇用我们目前的地质学学生参观他们的老高中，并传达他们对地球科学作为未来职业的兴奋。

Results from the proposed research will generate novel isotope measurements from barite, a highly stable and widely-distributed mineral found in magmatic, metamorphic, and sedimentary rocks of all ages, as well as in soils, aerosol dust, and extraterrestrial material. Establishing the controlling parameters of stable Sr-isotopic fractionation in barite will open a new avenue for geological and environmental research including geochemical, hydrogeological, hydrothermal, and paleoenvironmental studies. This fundamental research will lay the groundwork for future studies in the earth sciences using measurements of mass dependent Sr isotopes in barite. Barite may be an ideal vehicle to address critical questions in the earth sciences, including early earth biogeochemistry, evidence of potential life in extraterrestrial samples, reconstruction of temperatures in formation fluids such as springs and seeps, water rock interactions, tracking provenances of atmospheric inputs into soils, and reconstructing global changes in Sr2+ budgets during earth?s past.Very few laboratories in the world have developed methods to measure stable Sr-isotope ratios; and work on this new stable isotopic system proposed here will provide a unique opportunity to contribute to the development of this new isotope system in its beginning stages. Graduate and undergraduate students will have the opportunity to work and interact in multiple laboratories on this research project (at Kent State Univ., USC, Univ. of Akron, UCLA, Univ. of Oklahoma) thus developing and mentoring research and analytical skills. They will conduct careful experiments, collect samples in the field at an established field site in western Oklahoma and interact with students involved in this project as well as field sites in western Colorado and northern Utah. Outreach activities in local high schools will be established through a published hands-on learning module which investigates fundamental concepts of the ?greenhouse effect? and will employ our current geology students to visit their old high schools and relay their excitement for the geosciences as a future career.