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: 0809733
• 负责人: Erik Hauri
• 金额: $ 7.28万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0809733&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。了解与汇聚边缘岩浆作用相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异质性的基本要求。确定地幔中收敛边缘挥发物的预算和分布是了解弧火山生成过程的必要步骤。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型提供重要约束。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有关岩浆弧的组成、地壳和地壳的结构和演化的重要信息。地幔。然而，关于 SVZ 熔岩的挥发性浓度和稳定同位素组成的数据实际上不存在。该项目旨在通过确定选定的 SVZ 玄武岩中挥发物含量和同位素组成的区域差异来填补这一空白。新数据将帮助我们对大陆环境中收敛边缘的内部运作建立一个更加综合和现实的描述。它们将用于区分挥发物的来源（例如，板片脱水与俯冲沉积物），并测试板片通量与减压熔融模型。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，将为 SVZ 下方的地幔流动、熔体生产、迁移和地幔水化程度提供更可靠的表示。更广泛的影响。该项目将促进来自六个国内机构（布朗大学、DTM、FIU、康奈尔大学、CWRU、WHOI）和五个国外机构（阿根廷科尔多瓦大学、智利康塞普西翁大学、IFM- GEOMAR 和 GFZ-Postdam，德国；Okoyama U.，日本）。这些合作将实现交叉融合，使所有参与其中的科学家受益，样本、数据、模型和想法的共享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 WHOI 的 ICPMS 实验室将得到这项研究的财政支持。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。我们预计这两个机构都会发表几篇高级论文。因此，对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。