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

合作研究：安第斯山脉南部火山带的地球动力学，地球化学方法

• 批准号: 0810191
• 负责人: Alberto Saal
• 金额: $ 23.41万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0810191&HistoricalAwards=false
• 关键词: Collaborative; Research; Geodynamics; Andean; Southern

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.

智力上的优点。了解与会聚边缘岩浆活动有关的化学成分的分布和组成，是了解大陆地壳的起源、组成和演化以及地幔不均匀性的基本要求。建立预算和地幔中的挥发物在收敛边缘的分布是一个必要的步骤，以了解的过程负责弧火山的产生。挥发分影响地幔熔融、岩浆结晶和火山喷发，其丰度和空间分布对地幔流动、板片脱水和地壳再循环模式提供重要制约。在过去的30年里，安第斯山脉南部火山带（SVZ）得到了广泛的研究，地球化学、岩石学、地球物理、构造和地质研究提供了关于岩浆弧组成以及地壳和地幔结构和演化的重要信息。然而，有关SVZ火山岩的挥发物浓度和稳定同位素组成的数据实际上是不存在的。本项目旨在通过确定选定SVZ玄武岩的挥发物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建立一个更加综合和现实的内部工作在大陆环境中的收敛边缘的肖像。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），并测试板块通量与减压熔融模型。现有的地震信息，二维温度和流动模型与地球化学数据的结合将提供一个更可靠的表示地幔流动，熔体生产，迁移，以及在SVZ下面的地幔水合作用的程度。该项目将促进来自国内六个国家（布朗大学，DTM，FIU，康奈尔大学，CWRU，WHOI）和五个外国机构（美国。阿根廷科尔多瓦;孔塞普西翁，智利; IFM-GEOMAR和GFZ-Postdam，德国; Okoyama U.，日本）。这些合作将使所有参与的科学家受益，各方之间将自由交流样本、数据、模型和想法。三个实验室：布朗大学的Eprobe，DTM-CIW的离子探针和WHOI的ICPMS实验室将得到本研究的财政支持。该项目将支持布朗大学的一名博士生和几名本科生以及科尔多瓦大学的本科生。我们期待着两个机构的几个高级论文。因此，科尔多瓦大学地质系将首次开展对安第斯山脉近期火山活动的研究。