Collaborative Research: Volcanic Evolution in the Galapagos: A Geological, Petrological, and Geochemical Investigation of Volcan Ecuador

合作研究：加拉帕戈斯群岛的火山演化：厄瓜多尔火山的地质、岩石学和地球化学调查

• 批准号: 9612110
• 负责人: Dennis Geist
• 金额: $ 10.07万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-15 至 2000-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9612110&HistoricalAwards=false
• 关键词: Collaborative; Research; Volcanic; Evolution; Galapagos

9612110 Geist This project is an integrated field, petrological, and geochemical study of Volcan Ecuador, Isla Isabela, Galapagos. The immediate objectives of this study are as follows: 1. Determine the eruptive and structural history of the volcano through field studies and K-Ar dating. 2. Obtain a sufficiently complete suite of chemical data so that the liquid line of descent can be determined and the nature of the parental magmas constrained. 3. Identify any temporal trends in composition, through analysis of suites of samples whose ages are constrained by a combination of stratigraphy and K-Ar dating. For this purpose, samples will be taken from stratigraphic sections exposed in fault scarps and caldera walls. Determine what, if any, effect has the apparent faulting on Ecuador had on magma composition? Laboratory based work will include major element analyses, petrographic studies, electron microprobe analyses of mineral phases, Sr, Nd, Pb, and Hf isotopic analyses, and trace element analyses. The results obtained will be used, along with thermodynamic models of magmas, to model magma generation and evolution. These will be compared with the results of studies of other volcanoes in the Galapagos. This in turn will be used to address the problem of how the Galapagos mantle plume interacts with lithosphere and asthenosphere at shallow levels in the mantle beneath the Galapagos. The proposed study is a joint Franco-American project involving a collaboration between Francis Albarede of the Ecole Normale Superieure de Lyon, Dennis Geist of the University of Idaho, and William White of Cornell University.

9612110 Geist这个项目是对加拉帕戈斯的伊萨贝拉岛的火山厄瓜多尔进行的一项综合野外、岩石学和地球化学研究。本研究的近期目标如下：1.通过野外考察和K-Ar测年确定火山的喷发历史和构造历史。2.获得一套足够完整的化学数据，以便确定液态下降线并限制母岩浆的性质。3.通过对年龄受地层学和K-Ar年龄限制的样品进行分析，找出其组成的任何时间趋势。为此，将从断层陡坎和破火山口墙中暴露的地层剖面中提取样本。确定厄瓜多尔的明显断层对岩浆成分有什么影响？以实验室为基础的工作将包括主要元素分析、岩相学研究、矿物相的电子探针分析、锶、钕、铅和氢同位素分析以及微量元素分析。所获得的结果将与岩浆的热力学模型一起用于模拟岩浆的生成和演化。这些结果将与加拉帕戈斯其他火山的研究结果进行比较。这反过来将被用来解决加拉帕戈斯地幔羽流如何与加拉帕戈斯之下地幔浅层的岩石圈和软流圈相互作用的问题。这项拟议的研究是一个法美联合项目，涉及里昂高等学院的弗朗西斯·阿尔巴德、爱达荷大学的丹尼斯·盖斯特和康奈尔大学的威廉·怀特的合作。