Collaborative Research: NSF GEO-NERC: The Cracking of a Craton: Understanding Volatile Release during Continental Breakup

合作研究：NSF GEO-NERC：克拉通的破裂：了解大陆破裂期间的挥发物释放

• 批准号: 2319898
• 负责人: Tobias Fischer
• 金额: $ 32.08万
• 依托单位: University of New Mexico
• 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: 2023-12-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2319898&HistoricalAwards=false
• 关键词: Collaborative; Research; NSF; GEO; NERC

This is a project that is jointly funded by the National Science Foundation's Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own country.Cratons are the oldest and most stable parts of the Earth’s continents. During continental break-up or rifting events, these stable crustal areas split apart and eventually give way to magma rising from Earth’s deep interior and the formation of new crust. Volatile elements such as helium, nitrogen and carbon dioxide play an important role during all aspects of plate tectonics. Major volatiles are transported from the Earth’s surface into Earth’s interior during subduction and may accumulate below and within the stable cratons due to radiogenic production and upwelling from the mantle below. The mechanisms and time-scales of this accumulation remain poorly understood, yet are significant because these processes form reservoirs of economically valuable gases such as helium and hydrogen, and geologically important gases such as carbon dioxide. When cratons eventually break apart, these gases are released to the atmosphere and have potentially significant climatic impacts on geological time scales. The objective of this work is to determine the geological processes that control volatile production in the craton, their migration through the crust and release at the surface. The investigated field site is the area surrounding the Tanzania Craton, a type example of a stable craton surrounded by the East African Rift, and a location of intense magmatism and extensional tectonics. This particular geologic setting is ideally suited to investigate the formation processes of cratonic volatiles and their potential release mechanism due to magnetism and rifting. During the course of the project two Tanzanian students will get their Ph.D. education and experience at the Woods Hole/MIT graduate program and the University of New Mexico. The students will be trained in field and laboratory techniques, data interpretation and application of these techniques for understanding the processes of reservoir formation of these economically valuable gases. This project is a comprehensive study of the volatile gases that are being emitted from gas and water seeps along the flanks of the Tanzanian craton - a region where the stable continental craton is actively being “cracked” by rifting and simultaneously heated by plume-induced volcanism. The overall aims are to understand: 1) the mechanisms by which gases have been produced and stored in stable cratons over 109-year timescales, and 2) how they are liberated and transported to the surface during cratonic breakup. The study primarily focuses on helium (He) and nitrogen (N2) and their isotopic characteristics, which are the main constituents of cratonic gas accumulation, but we will measure all other noble gases (Ne, Ar, Kr, Xe) and their isotopes, CO2, CH4 (as well as their isotopes) and H2 in seeps. The PIs will use field- and lab-generated gas chemistry results to form an integrated model of gas formation and transport along the flanks of the Tanzania craton. Volatile fluxes will be calculated to understand the extent of gas release when a cratonic region is disrupted by rifting and volcanism. Determining how cratonic gases are released to the crust and eventually to the atmosphere is important for understanding volatile movements on large spatial and temporal scales. By constraining how volatiles are accumulated and released during steady-state rifting and magmatic conditions, the PIs will characterize cratonic volatile inventories and fluxes. This information will be of interest to the broader Earth science community, and provide valuable context to researchers studying the potential climatic effects when gases are abruptly released from the stable craton to the atmosphere as well as the formation of economically valuable gas reservoirs of helium and hydrogen. Two Tanzanian students will be jointly supervised by the PI’s of the award and trained in field and laboratory techniques at their respective institutions. There will be opportunity for the students to obtain in depth training in noble gas geochemistry, gas geochemistry and stable isotopes, as well as modeling approaches to understand the processes of formation of these economically valuable gas reservoirs.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.

这是一个由国家科学基金会地球科学局（NSF/GEO）和英国国家环境研究委员会（NERC）共同资助的项目。该协议允许该机构提交和同行评审的一项联合提案，其调查员的预算比例最大。成功确定裁决后，每个机构都为预算的比例和与其自己的国家相关的调查人员提供了资金。Cratons是地球上最古老，最稳定的部分。在连续分解或撕裂事件中，这些稳定的地壳区域分开，并最终使岩浆从地球深内部和新地壳形成中升起。氦，氮和二氧化碳等挥发性元素在板块构造的各个方面都起着重要作用。在俯冲期间，主要挥发物从地球的表面转移到地球内部，并且由于放射原源产生并从下面的地幔上升而在稳定的克拉通下以及稳定的cratons内部运输到地球内部。这种丙烯酸的机制和时间量表仍然很少了解，但很重要，因为这些过程形成了经济上有价值的气体（例如氦气和氢）的储层，以及地质上重要的气体，例如二氧化碳。当克拉通最终破裂时，这些气体会释放到大气中，并对地质时间尺度产生重大的杂交影响。这项工作的目的是确定控制克拉顿中挥发性产生的地质过程，它们通过外壳迁移并在表面释放。研究的现场是坦桑尼亚克拉顿（Tanzania Craton）周围的区域，这是东非裂谷周围稳定的craton的一个例子，以及强烈的岩浆和延伸构造的位置。这种特殊的地质环境非常适合研究克拉托挥发物的形成过程及其由于磁性和裂缝而引起的潜在释放机制。在项目过程中，坦桑尼亚两名学生将获得博士学位。伍兹霍尔/麻省理工学院研究生课程和新墨西哥大学的教育和经验。这些学生将接受培训，以了解这些经济有价值的气体的水库形成过程，以了解这些技术的数据解释和应用。该项目是对沿坦桑尼亚克拉顿（Tanzanian Craton）侧面渗出的挥发性气体的全面研究，该地区渗入坦桑尼亚克拉顿（Craton）的侧面 - 该地区稳定的连续克拉顿（Craton）通过裂解而通过裂缝被羽毛诱导的火山加热而积极地“破裂”。总体目的是要了解：1）在109年的时间标准的稳定的craton中生产并存储气体的机制，以及2）如何在克拉通分裂过程中解放并运输到表面。该研究主要侧重于氦（HE）和氮（N2）及其同位素特性，这些特性是克拉通气体积累的主要组成部分，但我们将测量所有其他所有贵重气体（NE，AR，KR，KR，XE）及其同位素，CO2，CO2，CH4（以及它们的同位素）（以及它们的同位素）和H2中的H2。 PI将使用现场和实验室生成的气体化学结果，形成沿坦桑尼亚克拉通的侧面的气体形成和运输的综合模型。将计算挥发性通量，以理解当裂谷和火山裂解破坏cratonic区域时气体释放程度。确定cratonic气体是如何释放到地壳上的，最终对大气的释放对于理解大型空间和临时尺度上的挥发性运动很重要。通过限制在稳态裂谷和岩浆条件下挥发物的积累和释放的方式，PIS将表征克拉托式挥发性库存和通量。该信息将引起广泛的地球科学界的关注，并为研究人员从稳定的克拉顿突然释放到大气以及经济上有价值的氦气和氢气储量时，为研究潜在气候影响提供了宝贵的背景。两名坦桑尼亚学生将由PI颁奖典礼共同监督，并在各自机构的现场和实验室技术中接受培训。学生将有机会在高贵的气体地球化学，气体地球化学和稳定的同位素方面进行深入培训，以及建模方法，以了解这些经济上有价值的气体储层的形成过程。这奖反映了NSF的立法任务，并通过基金会的智力效果和广泛的评估值得评估，这是值得通过评估来进行评估的。