CAREER: Heavy Noble Gases in the Azores Archipelago

职业：亚速尔群岛的重惰性气体

• 批准号: 2145663
• 负责人: Rita Parai
• 金额: $ 72.09万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2145663&HistoricalAwards=false
• 关键词: CAREER; Heavy; Noble; Gases; Azores

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.

地球上的大气和海洋在太阳系天体中是独一无二的。这些重惰性气体（氖气、氩气、氪气和氙气）追踪了挥发性元素和碳、氮和水等化合物的起源，以及它们的预算是如何随着时间在地球深处和地表储集层之间分布的。对来自地幔羽流影响地区的火山样本中重惰性气体的测量，已经对挥发物的起源和运输产生了新的见解，但精确的数据来自不寻常的样本，而不是典型的海底喷发的海洋岛屿玄武岩。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海洋岛屿玄武岩中的重惰性气体；这将阐明在亚速尔群岛取样的地幔柱在地球历史上是如何获得和失去挥发物的，并推动该领域更好地理解地幔柱挥发物的特征。将开发和传播一门现代课程，在统一的框架内展示用于研究地幔地球化学的不同同位素系统，以扩大从事深部地球化学高级研究的本科生的范围。重惰性气体（氖、氩、氪和氙）对挥发性吸积、早期地幔分异以及内部和地表储层之间的挥发性运输提供了独特而有力的见解。然而，由于样品脱气和大气污染，大多数海洋岛玄武岩中的重惰性气体难以测量。新的分析技术已经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上研究充分的地点进行采样，以获得大量新鲜材料，用于高精度分析氦、氖、氩、氪和氙的丰度和同位素比率。新的数据将用于探测地幔挥发物的起源，测试地幔柱间挥发物损失的非均匀特征，并研究深过去大气挥发物输送到地幔的效率。该项目将开发和测试一个新的地幔放射性成因同位素地球化学入门课程，包括稀有气体，在一个统一的框架内提出。通过研讨会和在线门户网站向教师传播课程，并促进课程整合，将增加和扩大从事地幔地球化学（包括惰性气体）高级研究的本科生人数。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。