Collaborative Research: RUI: The Origin and Evolution of the Galapagos Lithosphere, Floreana Volcano

合作研究：RUI：加拉帕戈斯岩石圈、弗洛雷纳火山的起源和演化

• 批准号: 0207425
• 负责人: Karen Harpp
• 金额: --
• 依托单位: Colgate University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-12-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0207425&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Origin; Evolution

HarppEAR-0207425Floreana Island is the most distinctive volcano of the Galapagos hotspot system. Unlike other Galapagos Islands, Floreana experienced extensive explosive activity, and its alkalic lavas are anomalously enriched in incompatible trace elements, exhibit evidence of metasomatism, have unique isotopic compositions, and contain abundant mantle xenoliths. The fundamental goal of the proposed project is to use Floreana's unique features to elucidate the magmatic processes that construct and modify the lithosphere forming the Galapagos Platform, which will be accomplished through a detailed volcanologic, petrologic, and geochemical study. Determining the volcanic history and compositional evolution of Floreana volcano will permit estimation of variations in the depths and extents of melt production through analysis of major and trace element variations and how those change with time. These results will be applied to questions about Floreana's volcanic evolution, including: a) the relationship between the different eruptive sequences; b) apparent shallow depths of melting, which may contradict a deep plume origin; c) compositional variations within single eruptive episodes; d) the relationship between Floreana lavas and the giant volcanic terraces which underlie the southern Galapagos Platform; and e) the origins of the xenoliths and their relationship to Floreana lavas and other parts of the Galapagos lithosphere. The powerful combination of high precision geochemical and petrologic analysis coupled with detailed field observations will provide a rare opportunity to gain insight into elusive questions about plume-lithosphere interaction, ocean-island magmatism, and, ultimately, mantle evolution.

Harppear-0207425floreana岛是加拉帕戈斯热点系统中最独特的火山。与其他加拉帕戈斯群岛不同，佛罗里亚州经历了广泛的爆炸活性，其碱性熔岩异常富集在不兼容的微量元素中，表现出交代的证据，具有独特的同位素组成，并且包含丰富的地幔Xenoliths。拟议项目的基本目标是利用Floreana的独特功能来阐明构建和修改岩石圈形成Galapagos平台的岩浆过程，该岩石圈将通过一项详细的火山学，岩石学和地球化学研究来完成。 通过分析主要和痕量元素变化以及这些时间如何随着时间的变化，确定佛罗里亚火山火山的火山历史和组成演变将允许估计熔体生产的深度和范围的变化。这些结果将应用于有关佛罗里亚州火山进化的问题，包括：a）不同喷发序列之间的关系； b）明显的熔化深度，这可能与深羽的起源相矛盾； c）单个喷发发作中的组成变化； d）弗洛雷亚纳熔岩与南部加拉帕戈斯台平台基础的巨大火山露台之间的关系； e）异种石的起源及其与弗洛雷纳熔岩和加拉帕戈斯岩石圈的其他部分的关系。高精度地球化学和岩石学分析以及详细的现场观察的强大组合将为难以置信的机会洞悉有关羽流圈相互作用，海洋爱岛岩浆主义的难以捉摸的问题，并最终，地幔进化。