CAREER: The Evolution of Super-Hydrous Magmas in the Earth's Crust

岩石学和地球化学是地质学和地球系统和过程研究的基石。实验研究往往是推动了解板块构造，特别是俯冲带的必要组成部分。这项建议描述了一个以实验岩石学、热力学和火山学为基础的综合研究和教学计划，以促进对火山如何工作、水如何影响火山演化及其行为的理解，同时提供新的实践教学工具，使目前处于研究生、本科或高中水平的未来岩石学家感到兴奋。特别是，这项提案将研究世界上最具爆炸性的活火山的喷发产物。这里提出的研究是一项实验和地球化学研究，主要是为了利用角闪石化学来量化地壳深部和上地幔条件下超水弧岩浆中喷发前的水含量。这项研究包括三项广泛的研究任务，它们将构成了解地球中挥发性通量和循环的新范式的基础，以及一项教育计划，该计划将开发将技术和岩石学教学结合在一起的新方法。该项目将承担四项相互关联的任务，旨在研究世界上产岩浆最多的火山区的岩浆储存和演化的喷发前动力学，并特别侧重于与超水岩浆有关的地球化学。进行实验的广泛目标是弥合我们对岩浆水含量认识上的差距，即水合熔剂熔融的终止，以及熔体包裹体的捕获和斜长石在地壳浅层的结晶。实验研究将探索水化岩浆的地球化学演化，并首次定量测量下地壳条件下角闪石中氢、氟和氯的分配。只有考虑到控制熔体和晶体之间的地球化学分配和角闪石脱氢的密集而广泛的变量，测量角闪石中的氢含量才能提供巨大的地质价值。将在受控的P、T、XH2O和fO2条件下进行闪石合成实验。结果将被纳入LEPR等数据库，并可用于纳入重要的社区热力学模型，如Melts及其后续的Enki。目前，角闪石是这些建模算法中唯一没有包括在内的主要相，这突显了对这种矿物进行一般实验研究的重要性。文献中较低地壳压力下的水合实验很少，这些实验将有助于填补这一空白。这项研究将扩大我们目前对角闪石稳定性的了解，角闪石是地壳中的一个重要阶段，但没有低压稳定场，因此它在产生弧形地球化学趋势方面的作用经常被低估。通过职业计划，PI将开发新的教学和推广工具，将改进岩石学课程中教授三元相图的方式，并制作可用于虚拟野外旅行和火山学推广的火山3D模型。这项工作的目标是：1。为本科生创建岩石学和火山学的实践教学方法，以提高理解和记忆。2.通过将新的可视化图像提供给其他本科院校，为这些学科的本科生创造激发兴奋的途径。为了实现这些目标，将实施一项计划，包括软件开发、课程开发和将3D渲染分发到AR应用程序平台。该奖项反映了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。

Petrology and geochemistry are cornerstones of geology and the study of Earth systems and processes. Experimental studies have often been the necessary component for advances in understanding plate tectonics and subduction zones in particular. This proposal describes an integrated research and teaching program with foundations in experimental petrology, thermodynamics, and volcanology, to advance the understanding of how volcanoes work, how water affects the evolution of volcanoes and their behavior, while providing new hands-on teaching tools to generate excitement for future petrologists currently at the graduate, undergraduate or high school level. In particular, this proposal will study the eruptive products from the most explosively active volcano in the world. The research proposed here is an experimental and geochemical study primarily designed to use amphibole chemistry to quantify pre-eruptive water contents in super-hydrous arc magmas at deep crustal and upper mantle conditions. This study consists of 3 broad research tasks that will form the foundation of a new paradigm for understanding volatile flux and recycling in the Earth, and an education plan that will develop new ways of bringing technology and teaching petrology together in the classroom. This project will undertake four interrelated tasks aimed at studying the pre-eruption dynamics of magma storage and evolution in the most magmatically productive volcanic area of the world and focuses specifically on geochemistry related to super-hydrous magmas. Experiments are to be executed with the broad goal of bridging the gap in our knowledge about magmatic water contents between the termination of hydrous flux melting, and the trapping of melt inclusions and crystallization of plagioclase in the shallow crust. Experimental studies will explore the geochemical evolution of hydrous magmas and make the first quantitative measurements on hydrogen, fluorine, and chlorine partitioning in amphibole at lower crustal conditions. Measuring the H contents in amphiboles will provide immense geologic value only if we can account for the intensive and extensive variables that control the geochemical partitioning between melt and crystal, and the dehydrogenation of amphibole. Amphibole synthesis experiments at controlled P, T, XH2O and fO2 will be conducted. Results will be incorporated into databases such as LEPR and be available to incorporate into important community thermodynamic models such as MELTS and its successor ENKI. Currently, amphibole is the only major phase not included in these modeling algorithms, highlighting the importance of general experimental studies on this mineral. There is a paucity of hydrous experiments at lower crustal pressures in the literature and these experiments will help to fill that gap. This study will be expanding our current knowledge of the stability of amphibole, an important phase in Earth's crust, but one without a low-pressure stability field so it has often gone under-appreciated in its role in producing geochemical trends at arcs.Through the CAREER program, the PI will develop new teaching and outreach tools that will improve the way ternary phase diagrams are taught in petrology classes, as well as produce 3D models of volcanoes that can be used for virtual field trips and volcanology outreach. The objectives of this effort are to: 1. Create hands-on methods for teaching petrology and volcanology to undergraduate students, to improve understanding and retention. 2. Create pathways to generate excitement in these subjects among undergraduates by making the new visualizations available for distribution to other undergraduate institutions. To achieve these goals a plan will be implemented that includes software development, curriculumdevelopment, and distribution of 3D renderings to the AR app platform.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.