Improved Constraints on Mantle and Crustal Source Signals in CO2 well gases: New Insights from Ultra-high Precision Noble Gas and Clumped Isotope Measurements

改进对 CO2 井气体中地幔和地壳源信号的约束：超高精度稀有气体和聚集同位素测量的新见解

• 批准号: 2321494
• 负责人: Michael Broadley
• 金额: $ 55万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2321494&HistoricalAwards=false
• 关键词: Improved; Constraints; Mantle; Crustal; Source

Volatile elements (like carbon, nitrogen, oxygen, water, and other gases) are critical for life on Earth. But there are still many open questions about how Earth formed, where volatile elements originated from, and how they move between the atmosphere, oceans, and Earth’s deep interior. By studying the gases that are released from inside Earth, we can learn more about the original sources of volatile elements. Different volatile origins will have different chemical signatures – akin to a fingerprint. Some of these chemical signatures may have been preserved deep within Earth's mantle for most of Earth’s history. In this research project, researchers will use new analytical techniques to study the composition of gases from Earth's mantle, focusing on samples from magmatic carbon dioxide (CO2) wells in Australia and the Colorado Plateau. This team also hopes to gain insight into how carbon dioxide can be stored underground, which could help us combat increasing levels of CO2 in the atmosphere and climate change. The natural movement of CO2 gas through Earth's subsurface can provide clues about how we can store CO2 effectively over long periods of time. In the Australian field site, magmatic CO2 gas is being re-injected into the ground to study whether long term geological storage is a viable tool to tackling rising atmospheric CO2 levels. This project will also provide opportunities for undergraduate students to gain experience in various aspects of scientific research such as fieldwork, laboratory work, modeling, and data analysis. Past measurements of noble gases in CO2 well gases in the Colorado Plateau provide important constraints on the cycling of volatiles within Earth’s mantle. Owing to their chemical and biological inertness, noble gases are exceptionally conservative tracers of sources and processes. New high-precision measurements of Ar, Kr, and Xe isotopes in CO2 well gas samples – made at 10 to 100 times higher precision than was previously attainable – will shed new light on the timing of volatile cycling and the cosmochemical origin of heavy noble gases in our atmosphere. Novel state-of-the-art measurements of clumped N2 and CH4 in these systems will provide unprecedented insight into the formation temperature and sources of volatiles, which will aid in understanding the recycling of deep nitrogen to the atmosphere and in disentangling biotic from abiotic methane production in hydrothermal systems. In cooperation with colleagues working on CO2 sequestration projects in Australia, measurements of noble gas isotopes made before, and after, test injection will be utilized as a novel tracer for subsurface transport of injected CO2, with possible implications for monitoring other sequestration sites worldwide. The new measurements made in this study will be shared with the broader community through a series of peer-reviewed publications, conference presentations, and will be made freely available to the public through online data repositories.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.

挥发性元素（例如碳，氮，氧，水和其他气体）对于地球上的生命至关重要。但是，关于地球的形成，挥发性元素的起源以及它们如何在大气，海洋和地球深内部的内部之间移动，仍然存在许多开放问题。通过研究从地球内部释放的气体，我们可以了解有关挥发性元素原始来源的更多信息。不同的挥发性起源将具有不同的化学特征 - 类似于指纹。这些化学特征中的一些可能已经在地球大部分历史上都保存在地球地幔中。在该研究项目中，研究人员将使用新的分析技术研究地球地幔的气体组成，重点是澳大利亚和科罗拉多高原的岩浆二氧化碳（CO2）井的样品。该团队还希望深入了解如何将二氧化碳存储在地下，这可以帮助我们打击大气和气候变化中二氧化碳水平的提高。二氧化碳气体通过地球地下的自然运动可以提供有关我们如何在长时间内有效存储CO2的线索。在澳大利亚现场，正在将岩浆二氧化碳气体重新注入地面，以研究长期地质存储是否是解决大气中二氧化碳水平上升的可行工具。该项目还将为本科生提供机会，以在科学研究的各个方面获得经验，例如实地研究，实验室工作，建模和数据分析。科罗拉多高原中二氧化碳气体中贵重气体的过去测量对地球内挥发物的循环产生了重要的限制。由于它们的化学和生物学惰性，高贵的气体是源和过程的绝对保守的示踪剂。二氧化碳气体样品中AR，KR和XE同位素的新的高精度测量值（比以前可实现的精度高10至100倍），将为我们氛围中挥发性循环的时机和宇宙化学的宇宙化学起源提供新的启示。这些系统中簇的N2和CH4的新最新测量将提供对挥发物的形成温度和来源的前所未有的见解，这将有助于理解深层的回收利用。在水热系统中，将生物剂与非生物甲烷产生的氮和使生物分解为氮。与从事澳大利亚二氧化碳隔离项目的同事合作，对之前进行的贵重同位素的测量将被用作注射二氧化碳的地下运输的新型示踪剂，并可能含义用于监测全球其他序列地点。这项研究中进行的新测量将通过一系列经过同行评审的出版物，会议演讲与更广泛的社区共享，并将通过在线数据存储库中自由向公众提供。该奖项反映了NSF的法定任务，并已通过评估基金会的知识和更广泛的影响来诚实地认为，通过评估诚实地将其视为诚实的支持。