Collaborative Research: Tectonic Links, Magma Fluxes, and Single Mineral Geochemistry in Plutonic Systems From 5-30 km Depth, Cascades Core, Washington

合作研究：5-30 公里深度的深成系统中的构造联系、岩浆通量和单一矿物地球化学，Cascades 核心，华盛顿智力成果。大陆岩浆弧是地幔衍生岩浆大量添加的场所，这些岩浆有助于推动地壳的熔化、增厚和重组。我们对白垩纪和更古老的大陆岩浆弧的了解大部分来自对深成岩物理和化学的研究，而衍生数据强烈影响地壳生长和演化的模型。与可以分析单个喷发单元的现代弧相比，岩体记录了更丰富但复杂的历史，并且比单独的火山岩代表了总岩浆通量的更大百分比。关键问题涉及中间成分岩浆如何以及以什么速度穿过地壳柱，以及地壳如何容纳这些潜在的大通量？回答这些问题的关键是了解大量结晶岩浆或岩体和岩基是如何形成的。为了解决这些问题，提出了合作研究，以更好地了解弧下岩浆管道系统。该项目的重点是北喀斯喀特大陆岩浆弧的根源，该岩浆弧由位于地壳不同深度的三个暴露良好的侵入体组成。将采用综合野外测绘、结构分析、矿物地球化学、高精度地质年代学和耦合同位素研究来[1]确定岩体代表单一岩浆批次或不同来源的部分结晶岩浆的复杂混合物的程度，[2]估计岩浆通量速率和中间成分岩浆熔体生成、输送和喷发的时间尺度，以及[3]评估区域构造应变和岩浆形成之间的潜在联系。这项多学科合作研究预计将大大有助于了解岩浆管道系统和大陆岩浆弧中岩体的形成。更广泛的影响。这项研究将支持博士学位。麻省理工学院和南加州大学的学生，以及至少 2 个硕士学位SJSU 的学生，以及所有 4 个机构的多名本科生助理。 Bpth SJSU PI 指导过 2 个 B.S.帕特森在南加州大学教授一个正式的研究课程，该课程有 20 名本科生参与了 NSF 支持的研究。 SJSU 和 USC 的研究生将访问 OSU 的肯特实验室进行自己的分析，麻省理工学院的研究生将访问 SJSU 并协助 SHRIMP 分析。四个硕士学位SJSU 的学生已前往 MIT 在 PI Bowring 和他的学生的指导下进行 U-Pb 测年，并且这种类型的互动预计将继续下去。所有 PI 都会定期将他们的研究纳入课堂讲座，并在实验室课程中使用研究样本。最重要的是，PI 正在向广大新生展示强大的跨学科和协作工作的力量。

Collaborative Research: Tectonic links, magma fluxes, and single mineral geochemistry in plutonic systems from 5-30 km depth, Cascades core, WashingtonIntellectual Merit. Continental magmatic arcs are the site of massive additions of mantle derived magmas which serve to drive melting, thickening, and reorganization of the crust. Much of what we know about Cretaceous and older continental magmatic arcs results from studies of the physics and chemistry of plutonic rocks, and the derivative data strongly influence models of crustal growth and evolution. In contrast to modern arcs where single eruptive units may be analyzed, plutons record a much richer, albeit complex, history and represent a much greater percentage of the total magmatic flux than volcanic rocks alone. Critical questions concern how and at what rate intermediate composition magmas move through the crustal column, and how the crust accommodates these potentially large fluxes? Key to answering these questions is to understand how large masses of crystallized magmas or plutons and batholiths are constructed. To address these questions, collaborative research is proposed to better understand sub-arc magmatic plumbing systems. This project focuses on the roots of a continental magmatic arc in the North Cascades that comprises three well-exposed intrusive bodies emplaced at different depths in the crust. Integrated field mapping, structural analysis, mineral geochemistry, high-precision geochronology and coupled isotopic studies will be employed to [1] determine the degree to which plutons represent single magma batches or complex mixtures of partially crystallized magmas of different origins, [2] estimate magma flux rates and timescales for melt generation, transport, and eruption of intermediate composition magmas, and [3] evaluate potential linkages between regional tectonic strain and magma formation. This multidisciplinary collaborative research is expected to contribute significantly to understanding of magma plumbing systems and the formation of plutons in continental magmatic arcs.Broader Impacts. This research will support Ph.D. students at MIT and USC, and at least 2 M.S. students at SJSU, and multiple undergraduate student assistants at all 4 institutions. Bpth SJSU PIs have supervised 2 B.S. research projects supported by their most recent grants, and Paterson teaches a formal research class at USC that has involved 20 undergraduates in NSF-supported research. Graduate students from SJSU and USC will visit Kent's lab at OSU to conduct their own analyses, and the MIT graduate student will visit SJSU and assist in SHRIMP analyses. Four M.S. students at SJSU have gone to MIT to carry out U-Pb dating under the tutelage of PI Bowring and his students, and this type of interaction is expected to continue. All of the PIs routinely incorporate their research in class lectures and use research samples in lab courses. Most importantly, The PI's are demonstrating to a large cross section of new students the power of strongly interdisciplinary and collaborative work.