CAREER: Heavy Noble Gases in the Azores Archipelago

在太阳系天体中，陆地大气和海洋是独一无二的。重惰性气体(霓气、氩气、氪和氙气)追踪挥发性元素和化合物(如碳、氮和水)的来源，以及它们的收支随着时间的推移在地球深处和地表水库之间的分配情况。对受地幔热柱影响地区的火山样品中重惰性气体的测量，为不稳定的来源和运输提供了新的见解，但准确的数据来自不寻常的样品，而不是典型的海底喷发的洋岛玄武岩。这项综合研究和教育工作将利用新的技术能力来测量亚速尔群岛海底喷发的洋岛玄武岩中的重惰性气体；这将阐明在亚速尔群岛采样的地幔热柱如何在地球历史上获得和损失挥发物，并推动该领域朝着更好地了解地幔热柱挥发性特征的方向发展。将开发和传播一门现代课程，其中介绍了在统一框架内用于研究地幔地球化学的不同同位素系统，以扩大对地球深处地球化学进行高级研究的本科生队伍。重惰性气体(Ne、Ar、氪和Xe)提供了关于挥发分吸积、早期地幔分异以及内部和地表储集层之间的挥发分运输的独特和强大的见解。然而，由于样品脱气和大气污染，在大多数洋岛玄武岩中很难测量到重惰性气体。新的分析技术使得能够测量从海洋岛屿橄榄石的大气成分中分解出来的重惰性气体成分。该项目将对亚速尔群岛经过充分研究的地点进行采样，以获得大量新材料，用于高精度地分析氦、氦、氩、氪和氙气的丰度和同位素比率。新的数据将用于探测地幔挥发分的来源，测试地幔热柱之间挥发分损失的不同特征，并调查大气挥发分在深部过去进入地幔的效率。该项目将开发和测试在统一框架内提出的关于包括惰性气体在内的地幔放射性同位素地球化学的新的入门课程。通过研讨会和在线门户网站向教师传播课程，并促进其与课程的整合，将增加和扩大对地幔地球化学(包括稀有气体)进行高级研究的本科生人数。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The terrestrial atmosphere and ocean are unique among Solar System bodies. The heavy noble gases (neon, argon, krypton and xenon) trace where volatiles elements and compounds like carbon, nitrogen and water originated and how their budgets have been distributed between the deep Earth and surface reservoirs over time. Measurements of heavy noble gases in volcanic samples from localities influenced by mantle plumes have yielded new insights into volatile origins and transport, but precise data have come from unusual samples, rather than typical subaerially-erupted ocean island basalts. This integrated research and educational work will harness new technical capabilities to measure heavy noble gases in subaerially-erupted ocean island basalts from the Azores archipelago; this will shed light on how the mantle plume sampled at the Azores acquired and lost volatiles over Earth history and advance the field towards a better understanding of mantle plume volatile signatures. A modern curriculum that presents different isotope systems used to study the geochemistry of the mantle within a uniform framework will be developed and disseminated to broaden the pool of undergraduates who pursue advanced study of the geochemistry of the deep Earth. The heavy noble gases (neon, argon, krypton and xenon) provide unique and powerful insights into volatile accretion, early mantle differentiation, and volatile transport between the interior and surface reservoirs. However, heavy noble gases are difficult to measure in most ocean island basalts due to sample degassing and atmospheric contamination. New analytical techniques have enabled the measurement of heavy noble gas compositions resolved from the atmospheric composition in olivines from ocean islands. This project will sample well-studied sites in the Azores archipelago to obtain large quantities of fresh material for high-precision analysis of helium, neon, argon, krypton and xenon abundances and isotopic ratios. New data will be used to probe mantle volatile origins, test for heterogeneous signatures of volatile loss among mantle plumes, and investigate the efficiency of atmospheric volatile transport into the mantle in the deep past. This project will develop and test a new introductory curriculum for mantle radiogenic isotope geochemistry including noble gases, presented within a unifying framework. Work to disseminate the curriculum to teachers through a workshop and online portals and facilitate its integration into courses will increase and broaden the pool of undergraduates who pursue advanced study of mantle geochemistry, including the noble gases.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.