Deconvolving Magmatic, Crustal and Atmospheric Gases in Yellowstone using a Coupled Noble Gas and Nitrogen Isotope Approach

使用耦合稀有气体和氮同位素方法对黄石公园的岩浆、地壳和大气气体进行反卷积

• 批准号: 2151120
• 负责人: Peter Barry
• 金额: $ 59万
• 依托单位: Woods Hole Oceanographic Institution
• 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 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2151120&HistoricalAwards=false
• 关键词: Deconvolving; Magmatic; Crustal; Atmospheric; Gases

The Earth’s surface is rich in volatile elements (e.g., H, C, N), providing the unique conditions that sustain life on our planet. However, the origin of terrestrial volatiles remains enigmatic, with considerable debate and uncertainty surrounding regarding volatile source(s) and the overall timing of planetary accretion. Analyzing the composition of primordial gases emanating from Earth's mantle represents one of the best avenues to determine the origin of terrestrial volatiles. The Yellowstone–Columbia River volcanic mega-province is one of the few volcanic localities on Earth where pristine, plume-derived magmatic gas reaches the surface and can be easily collected for analysis. Geochemical data from previous studies in Yellowstone suggest that gas vents are sourced from a deep-seated mantle plume, that is dominantly chondritic in origin. In this project, a comprehensive study of gas emissions from Yellowstone National Park (YNP) will be conducted. The aims are to: (i) investigate the nature and extent of the Yellowstone plume's interaction with the Archean-aged crustal basement, which will provide further insight into (ii) the source of the YNP plume, and the (iii) processes acting to obfuscate mantle source signals. Specifically, the proposed research will constrain the composition of YNP magmatic gases and their parental plume mantle source with unprecedented spatial and analytical resolution. The PIs will employ static noble gas mass spectrometry techniques, clumped N isotope measurements and the first ultra-high-precision (sub per mil (‰) precision) dynamic mass spectrometry measurements of magmatic gas to deconvolve mantle, crustal and atmospheric endmembers and to place firmer constraints on the origin of volatiles in the Yellowstone plume, which will help pinpoint the origin of volatiles on Earth. Questions pertaining to the origin of volatiles on Earth are of broad interest to the scientific community. Results from this study will provide insight into the relationship between mantle volatiles and Earth’s atmospheric composition, which is of direct relevance to understanding the drivers of Earth’s habitability and the subsequent evolution of life. Findings will be communicated to the scientific community through peer-reviewed publications and to the public through a multi-faceted outreach approach, including newsletter publications and field-based lectures that will be simulcast as a Facebook Live Event in coordination with YNP rangers. Further, the PIs will work with the YNP Exhibits Specialist to incorporate geochemical findings from this and other studies into a permanent “wayside exhibit” within the park. If possible, a short geochemical synopsis will also be included in the YNP welcome packet (distributed to the 4 million annual visitors). Additionally, an interactive website presenting a “Yellowstone Geochemical Trail Map.” will also be constructed and linked to the aforementioned wayside exhibit and entry brochure.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.

地球表面富含挥发性元素(如H、C、N)，为维持地球上的生命提供了独特的条件。然而，陆地挥发物的起源仍然是个谜，关于挥发性物质的来源(S)和行星吸积的总体时间，存在相当大的争论和不确定性。分析源自地幔的原始气体的组成是确定陆地挥发物来源的最佳途径之一。黄石-哥伦比亚河火山巨型省是地球上为数不多的几个火山地点之一，那里有原始的、从羽流中产生的岩浆气体到达地表，可以很容易地收集起来进行分析。黄石公园之前研究的地球化学数据表明，气体喷口来自深部地幔热柱，其来源主要是球粒陨石。在这个项目中，将对黄石国家公园的气体排放进行全面的研究。其目的是：(1)调查黄石热柱与太古代地壳基底相互作用的性质和程度，这将进一步深入了解(2)扬子岩柱的来源，以及(3)混淆地幔源信号的过程。具体地说，拟议的研究将以前所未有的空间和分析分辨率限制YNP岩浆气体及其母地幔来源的组成。PIS将采用静态惰性气体质谱学技术、块状N同位素测量和第一次岩浆气体超高精度(每毫升(‰)精度)动态质谱学测量，以去卷积地幔、地壳和大气端元，并对黄石羽流中挥发物的来源施加更严格的限制，这将有助于查明地球上挥发物的来源。有关地球上挥发物来源的问题引起了科学界的广泛兴趣。这项研究的结果将深入了解地幔挥发分与地球大气成分之间的关系，这对于理解地球宜居和随后生命进化的驱动因素具有直接关系。调查结果将通过同行评议的出版物向科学界传播，并通过多方面的外联办法向公众传播，包括通讯出版物和实地讲座，这些讲座将在YNP护林员的协调下作为Facebook Live活动同时转播。此外，PIS将与YNP展品专家合作，将这项研究和其他研究的地球化学结果纳入公园内的永久“路边展品”中。如有可能，YNP欢迎邮包内亦会附上简短的地球化学摘要(派发给每年400万名参观者)。此外，还建立了一个互动网站，展示“黄石公园地球化学轨迹图”。该奖项反映了NSF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。