Collaborative Research: The Geodynamics of the Andean Southern Volcanic Zone, A Geochemical Approach

知识价值。了解与会聚边缘岩浆作用有关的化学成分的分布和组成是理解大陆地壳的起源、组成和演化以及地幔的非均质性的基本要求。建立地幔辐合边缘挥发物的收支和分布是理解弧火山形成过程的必要步骤。挥发物影响地幔熔融、岩浆结晶和火山喷发，其丰度和空间分布为地幔流动、板块脱水和地壳再循环模型提供了重要约束。在过去的30年里，人们对安第斯南火山区（SVZ）进行了广泛的研究，地球化学、岩石学、地球物理、构造和地质研究为岩浆弧的组成、地壳和地幔的结构和演化提供了重要信息。然而，关于SVZ熔岩挥发性浓度和稳定同位素组成的数据几乎不存在。该项目旨在通过确定选定的SVZ玄武岩中挥发性含量和同位素组成的区域变化来填补这一空白。新的数据将帮助我们对大陆环境中辐合边缘的内部工作建立一个更完整、更真实的描述。它们将用于区分挥发物的来源（例如，板块脱水与俯冲沉积物），并用于测试板块通量与减压融化的模型。将现有的地震信息、二维温度和流动模型与地球化学数据相结合，可以更可靠地描述SVZ下地幔流动、熔体产生、迁移和地幔水化程度。更广泛的影响。该项目将促进来自6个国内机构（布朗大学，DTM， FIU，康奈尔大学，CWRU， WHOI）和5个国外机构（阿根廷科尔多瓦大学，智利康塞普西昂大学，德国IFM-GEOMAR和GFZ-Postdam，日本Okoyama大学）的地球物理学家，地球化学家和地球动力学家之间的合作。这些合作将允许交叉受精，这将使所有参与的科学家受益，在那里，样本、数据、模型和想法将在各方之间自由流动。三个实验室：布朗大学的Eprobe、DTM-CIW的离子探针和世卫组织的icpms实验室将得到本研究的财政支持。该项目将资助布朗大学和科尔多瓦大学的一名博士生和几名本科生。我们期待两所大学都能发表几篇高级论文。因此，最近安第斯火山活动的研究将首次在科尔多瓦大学地质系进行。

Intellectual merit. Knowledge of the distribution and composition of the chemical components associated with convergent margin magmatism is a fundamental requirement for understanding the origin, composition and evolution of the continental crust and the heterogeneity of the mantle. Establishing the budget and distribution of volatiles in the mantle at convergent margins is a necessary step to understand the processes responsible for the generation of arc volcanoes. Volatiles influence mantle melting, magma crystallization and volcanic eruption, and their abundances and spatial distribution provide important constraints on models of mantle flow, slab dehydration and crustal recycling. Over the last 30 years, the Andes Southern Volcanic Zone (SVZ) has been extensively investigated, with geochemical, petrological, geophysical, tectonic and geological studies providing important information on the composition of the magmatic arc, and the structure and evolution of the crust and mantle. However, data on volatile concentration and stable isotopic composition of lavas from the SVZ are virtually nonexistent.This project aims to fill this gap by determining regional variations in volatile contents and isotopic composition in selected SVZ basalts. The new data will help us build a more integrated and realistic portrait of the inner-workings at convergence margins in continental environments. They will be used to discriminate sources of volatiles (e.g., slab dehydration vs. subducted sediments) and to test models of slab-flux versus decompression melting. Combination of the existing seismic information, and two-dimensional temperature and flow models with the geochemical data will provide a more reliable representation of the mantle flow, melt production, migration, and extent of the mantle hydration beneath the SVZ.Broader Impact. This project will promote collaboration between geophysicists, geochemists and geodynamicists from six domestic (Brown U., DTM, FIU, Cornell U., CWRU, WHOI) and five foreign institutions (U. Cordoba, Argentina; U. Concepcion, Chile; IFM-GEOMAR and GFZ-Postdam, Germany; Okoyama U., Japan). These collaborations will allow cross-fertilization that will benefit all scientists involved, where the sharing of samples, data, models and ideas will flow freely between the parties. Three laboratories: the Eprobe at Brown U., the ion-probe at DTM-CIW, and the ICPMS-labs at WHOI will be financially supported by this research. The project will support one PhD student and several undergraduates from Brown University and undergraduates from University of Cordoba. We anticipate several senior theses from both institutions. Thus, research on recent Andean volcanism will be represented for the first time in the Geology Department at the Universidad de Cordoba.