Multiple Episodes of Fluid-Rock Interaction in Meta- Anorthosite Northwest of the Idaho Batholith

爱达荷基岩西北部变斜长岩中的多次流体-岩石相互作用

• 批准号: 8922638
• 负责人: Claudia Mora
• 金额: $ 7.22万
• 依托单位: University of Tennessee Knoxville
• 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: 1989-12-01 至 1992-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8922638&HistoricalAwards=false
• 关键词: Multiple; Episodes; Fluid; Rock; Interaction

The Boehls Butte anorthosite is exposed within the broad border zone of the northern Idaho batholith and has experienced multiple episodes of fluid-rock interaction, including magmatic, regional metamorphic and meteoric-hydrothermal events. This study will examine the stable isotopic and geochemical effects of superimposed fluid-rock interaction on the anorthosite and metasediments at its contact. The objectives of this study are (1) to differentiate the isotopic and geochemical effects of post-metamorphic and synmetamorphic fluid-rock interaction, (2) to constrain the relative contributions of igneous, metamorphic and hydrothermal processes to the development of unique mineralogies and isotopic compositions in the anorthosite and (3) to determine the extent to which regional metamorphism was accompanied by, or merely overprinted by, hydrothermal fluid convection associatated with batholith intrusion. Fluid-rock interaction will be characterized by a combine study of stable isotopes, fluid inclusions, mineral-fluid equilibria and trace element geochemistry. The results will constrain the depth, magnitude and timing of convective fluid flow through metamorphic rocks in the border zone of the batholith, constraining the efficacy of deep-seated fluid convection as a dynamic process in regional metamorphism.

Boehls Butte斜长岩出露于宽 北方爱达荷州岩基的边缘地带， 多期流体-岩石相互作用，包括岩浆， 区域变质和大气热液事件。 这 研究将检查稳定同位素和地球化学效应， 斜长岩上叠加的流体-岩石相互作用， 在其接触处的沉积物。 本研究的目的是 (1)区分同位素和地球化学效应 变质后和同变质流体-岩石相互作用; 来限制火成岩、变质作用 和热液过程， 斜长岩的矿物学和同位素组成; 以确定区域变质作用 伴随着或仅仅是叠加着热液流体 与岩基侵入有关的对流。 水岩 相互作用将通过稳定联合收割机研究来表征 同位素、流体包裹体、矿物-流体平衡和微量元素 元素地球化学 结果将限制深度， 对流流体通过变质作用的大小和时间 在岩基边界地带的岩石， 深部流体对流作为一种动态过程在 区域变质作用