CAREER: Tracking mantle carbon through the life cycle of Large Igneous Provinces

纵观地球历史，被称为大火成岩省(LIP)的巨大火山喷发与大规模灭绝和气候变暖事件同时发生。跟踪这些喷发释放的二氧化碳是解决岩浆活动和观测到的气候变化之间联系的关键。然而，由于二氧化碳倾向于从岩浆中泄漏出来，测量过去喷发时的二氧化碳是具有挑战性的。这项职业奖将使用从可能记录过去二氧化碳浓度的三个嘴唇中精心挑选的样本来调查不同的嘴唇来源。这项工作的目标是阐明一些唇部喷发如何、何时以及为什么会对地球上的气候和生命造成重大破坏，而其他一些则不会。新的方法将跟踪地球更深处的二氧化碳，提供对过去气候的估计，并帮助预测未来的气候变化。该项目在本科课程中使用同伴辅导，将研究、公众参与和教学结合在一起。这项工作还支持在学生群体多样化的公共机构进行研究生和本科生培训。该项目的一部分包括与一位电影制作人合作，通过一部新的纪录片和纽约虚拟火山观测站的外联活动来传达过去气候破坏的教训。这部电影和推广活动将使每年夏天数以千计的游客获得探索火山的体验。这项工作的两个主要科学目标是寻找嘴唇岩浆中最真实的岩浆二氧化碳记录，并控制不同的地幔来源，以了解嘴唇生命周期中的地幔碳释放。因此，这个项目建立了一系列自然实验的框架，这些实验对比了：1)不同类型的熔体包裹体挥发性和微量元素记录，以及2)来自海洋和大陆嘴唇的样品，这些样品利用了不同的和不断演变的地幔来源。这些自然实验将揭示玄武岩岩浆中各种二氧化碳岩石学档案的优势和劣势，包括一系列熔融包裹体寄主晶体和原始二氧化碳的地球化学替代物。这一结果将被用来检验一种假设，即决定气候变暖和碳循环破坏的严重程度和速度的是在嘴唇熔融期间挖掘的不断演化的地幔储集层--而不是通常认为的沉积围岩--以回应岩浆作用。如果成功，这个项目将阐明地幔中鲜为人知的储集层的挥发性系统学，包括大陆地幔岩石圈、羽流中的回收物质和高3He/4He原始地幔-在这个过程中，展示了地幔中嘴唇的起源如何设定地表二氧化碳排放和气候变化的蓝图。这一奖项反映了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。

Throughout Earth’s history, enormous volcanic eruptions known as Large Igneous Provinces (LIPs) coincide with mass extinction and climate warming events. Tracking CO2 release from these eruptions is key to resolving links between magmatism and observed climatic changes. However, because CO2 tends to leak out of magmas, measuring CO2 from past eruptions is challenging. This CAREER award will investigate distinct LIP sources using carefully selected samples from three LIPs that may record past CO2 concentrations. The goal of this work is to clarify how, when, and why some LIP eruptions cause major disruptions in climate and life on Earth but others do not. New approaches will track CO2 deeper in the Earth, inform estimates of past climate, and help to project future climate change. The project uses peer mentoring in undergraduate course to integrate research, public engagement and teaching. The work also supports graduate and undergraduate student training at a public institution with a diverse student population. Part of the project includes collaboration with a film-maker to convey lessons from past climate disruptions through a new documentary and outreach at the New York Virtual Volcano Observatory. The film and outreach will make the experience of exploring a volcano accessible to thousands of visitors each summer. The two primary scientific objectives of this work are to find the most faithful records of magmatic CO2 in LIP magmas, and to control for different mantle sources to understand mantle carbon release through the life cycle of LIPs. Accordingly, this project frames a series of natural experiments that contrast: 1) different types of melt inclusion volatile and trace element records, and 2) samples from oceanic and continental LIPs that tap distinct and evolving mantle sources. These natural experiments will reveal the strengths and weaknesses of various petrologic archives of CO2 in basaltic magmas, including a range of melt inclusion host crystals and geochemical proxies for original CO2. The results will be used to test the hypothesis that it is the evolving mantle reservoirs tapped during LIP melting—rather than sedimentary country rocks as is commonly assumed—that determine the severity and pace of climatic warming and carbon cycle disruption in response to magmatism. If successful, this project will elucidate the volatile systematics of poorly understood reservoirs in the mantle including the continental mantle lithosphere, recycled material in plumes, and high 3He/4He primordial mantle—in the process demonstrating how the origins of LIPs in the mantle can set the blueprint for surface CO2 release and climate change.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.