Gravitational Instability in Coexisting Layered Magmas: Isle au Haut, Maine

共存层状岩浆中的重力不稳定：缅因州奥豪特岛

• 批准号: 8904693
• 负责人: John Rhodes
• 金额: $ 6.22万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-15 至 1992-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8904693&HistoricalAwards=false
• 关键词: Gravitational; Instability; Coexisting; Layered; Magmas

This proposal seeks funding for an integrated field, geochemical and petrographic study of a granite-diorite-gabbro association on the island of Isle au Haut, Maine. These rocks are part of the more extensive Bays-of-Maine Igneous Complex. A major concern of this research will be to document and understand a spectacularly exposed sequence of layered gabbro and diorite units which we believe to be the frozen relics of a sequence of coexisting melts. Field relationships show clearly that several of these layers were gravitationally unstable, and were in the process of overturning and mixing. Recent theoretical studies applying fluid dynamics to magma chamber models predict that compositionally zone magma chambers, stratified magmatic layers, and mixing of distinct magma types play important roles in the petrogenesis of igneous rocks. On Isle au Haut we have, perhaps for the first time, an unprecedented opportunity to obtain systematic petrographic and geochemical data on coexisting magmas within a stratified magma chamber. From this data we will be able to evaluate many of the magmatic processes predicted to occur in magma reservoirs by recent fluid dynamics and experimental studies.

本提案寻求为一个综合领域提供资金， 花岗闪长辉长岩地球化学和岩相学研究 在缅因州的Au Haut岛上的协会。 这些岩石 是更广阔的缅因州湾火成岩复合体的一部分。 一 这项研究的主要关注点是记录和理解 一个层状辉长岩和闪长岩的异常暴露序列 我们认为这些单位是一系列 共存熔体 现场关系清楚地表明， 这些层的重力不稳定，并且处于 翻转和混合的过程。 近期理论研究 将流体动力学应用于岩浆房模型预测， 成分带岩浆房，层状岩浆层， 不同岩浆类型的混合作用在 火成岩的岩石成因 在Au Haut岛上，我们可能第一次看到了 前所未有的机会，获得系统的岩相和 层状岩浆中共存岩浆的地球化学数据 室。 从这些数据中，我们将能够评估许多 岩浆过程预测发生在岩浆库中， 最近的流体动力学和实验研究。