MCA: Advances in Understanding the Biogeochemical Evolution of Serpentinites (AUBES)

该项目由地球科学部的中期职业发展（MCA）计划和刺激竞争性研究的既定计划（EPSCoR）共同资助。微生物生命在数十亿年的地球历史中完善了矿物的精细化学，留下了复杂，持久的代谢活动记录。 岩石中的裂缝网络保存了这些古老过程的持久矿物记录，经常触及与地球上岩石宿主微生物生命的起源和早期适应策略有关的问题。 在该项目中，地球化学研究的目标是通过科学钻探在北方加州海岸山脉蛇绿岩中收集的来自地幔的富铁岩石（也富含铬、镍和其他金属）。 这些约1.5亿年前的岩石中的断裂带是地下古代条件下微生物活动的热点。 这项工作使用了一系列的地球化学工具来绘制裂缝中形成的材料的化学性质，并应用了一种基于高能X射线的技术（Fe K边XANES）来定义裂缝填充矿物中的氧化或还原结合铁可能是如何的，作为过去铁（用于能量）的地球化学循环的证据。研究涉及与布鲁克海文国家实验室的专业光束线科学家和主题专家D。霍利奥克山学院的戴尔。增加了对这种岩石类型中矿物反应的了解（全球海底下巨大的连续地层，也存在于地球表面的广泛区块）带来了多种社会效益：（一种温室气体）和氢气使用地球化学模型可以更好地限制来自这些岩石的铁和伴生金属（易燃但快速损失的气体产物）的释放;铁和伴生金属的释放（例如，有害健康的Cr 6+）进入通过这些岩石的净化水中的可能性可以被绘制成图表并标记以引起公众健康注意;并且可以评估这些种类的岩石与二氧化碳的工程反应以产生固体中的螯合碳的情况。 这项研究的完成还将确保多个新一代地球科学家将通过多元化和公平意识的研究生和本科生教育接受尖端分析工具的培训。该奖项反映了NSF的法定使命，并通过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，被认为值得支持。

This project is jointly funded by the Division of Earth Sciences' Mid-Career Advancement (MCA) Program and the Established Program to Stimulate Competitive Research (EPSCoR).Microbial life has refined the fine-scale chemistry of minerals for billions of years of Earth history, leaving complex, durable records of metabolic activity behind. Fracture networks in rocks preserve a durable mineral record of these ancient processes, often touching questions related to the origin and early adaptive strategies of rock-hosted, microbial life on Earth. In this project, iron-rich rocks (also high in chromium, nickel, and other metals) from Earth’s mantle, collected through scientific drilling in northern California’s Coast Range Ophiolite, are targeted for geochemical study. Fracture zones in these ~150-million-year-old rocks were hotspots of microbial activity under ancient conditions in the subsurface. This work uses an array of geochemical tools to map the chemistry of materials formed in fractures and applies a high energy x-ray-based technique (Fe K edge XANES) to define how oxidized or reduced bound iron in fracture fill minerals may be, as evidence for biogeochemical cycling of iron (for energy) in the past. Research involves collaboration with professional beamline scientists at Brookhaven National Lab and with topic expert Dr. D. Dyar of Mount Holyoke College. Increased understanding of the mineral reactions in this rock type (an enormous, continuous layer beneath the global seafloor and also present in extensive blocks at Earth’s surface) brings multiple societal benefits: the incompletely understood emissions of naturally forming methane (a greenhouse gas) and hydrogen (a flammable but quickly lost gaseous product) from these rocks may be better constrained using geochemical models; the release of iron and associated metals (e.g., health-damaging Cr6+) into percolating water passing through these rocks may be charted and flagged for public health attention; and the case for engineered reaction of these kinds of rocks with carbon dioxide to generate sequestered carbon in solids may be evaluated. Completion of this research will also ensure that multiple new generation geoscientists will be trained in cutting edge analytical tools, through diversity- and equity-minded graduate and undergraduate education.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.