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：构造联系，岩浆通量，和单矿物地球化学深成系统从5-30公里深，瀑布核心，华盛顿州。大陆岩浆弧是幔源岩浆大量增积的场所，这些岩浆的作用是驱动地壳的熔融、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石物理和化学的研究，而衍生数据强烈影响着地壳生长和演化的模型。与现代弧不同的是，现代弧可以分析单个喷发单元，而深成岩记录了更丰富的历史，尽管复杂，并且比单独的火山岩占总岩浆流量的百分比要大得多。关键的问题是如何和以什么速度中间组成的岩浆移动通过地壳柱，以及地壳如何容纳这些潜在的大流量？回答这些问题的关键是要了解大量的结晶岩浆或深成岩和岩基是如何构成的。为了解决这些问题，建议进行合作研究，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山脉大陆岩浆弧的根源，该岩浆弧包括三个位于地壳不同深度的暴露良好的侵入体。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将用于[1]确定岩体代表单一岩浆批次或不同起源的部分结晶岩浆的复杂混合物的程度，[2]估计岩浆流量率和熔体生成、运输和中间成分岩浆喷发的时间尺度，[3]评价区域构造应变与岩浆形成之间的潜在联系。这一多学科的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的岩体形成。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，至少2个硕士学位。学生在SJSU，和多个本科生助理在所有4个机构。Bpth SJSU PI监督了2个B.S. Paterson教授在南加州大学教授一个正式的研究班，有20名本科生参与了NSF支持的研究。来自SJSU和南加州大学的研究生将访问肯特在俄勒冈州立大学的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。四个硕士在PI Bowring和他的学生的指导下，SJSU的学生已经去麻省理工学院进行U-Pb测年，这种类型的互动预计将继续下去。所有的PI都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正在向大量的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.