Re-Os Isotopic Systematics Accompanying the Conversion of Organic-Rich, Pelitic Country Rocks to Hornfels, Magma Contamination and Sulfide Ore-Genesis, Duluth Complex

富含有机物的泥质乡村岩石转化为角岩的铼锇同位素系统学、岩浆污染和硫化物成矿，德卢斯杂岩

• 批准号: 9814204
• 负责人: Edward Ripley
• 金额: $ 11.3万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814204&HistoricalAwards=false
• 关键词: Re; Os; Isotopic; Systematics; Accompanying

9814204RipleyBecause of the enrichment of Re relative to Os in mantle-derived, basaltic partial melts, and the high Re/Os ratio of crustal rocks, the Re/Os isotopic system has proven to be a sensitive tracer in the evaluation of dynamic interaction processes between crust and mantle-derived mafic magmas. In the assessment of country rock contamination the application of the Re-Os isotopic system as a petrologic tracer is dependent upon the proper evaluation of open- or closed-system behavior in the contaminant rock, and immobility of Re and Os after crystallization of the igneous rock or sulfide-rich ore material. This project will evaluate the distribution and isotopic characteristics of Re and Os in organic-rich sedimentary rocks, changes in isotopic characteristics during contact metamorphism and conversion of these rocks to hornfels, and isotopic variation found in sulfide-bearing igneous rocks produced as a result of assimilation of country rocks or a released fluid phase. The geologic setting of the Duluth Complex and Proterozoic country rocks presents an excellent opportunity to trace the evolution of the Re-Os system through the processes of contact metamorphism and dehydration, and assimilation of country rocks by mafic magma. Both crustally-contaminated and uncontaminated gabbroic and troctolitic rocks are present in the area of the Babbitt Cu-Ni deposit, and systematic Re-Os analyses will permit an in-depth evaluation of the causes of isotopic variability that may originate as a result of metamorphic and hydrothermal processes in the country rocks, and magmatic processes related to changes in the ratio of silicate magma to sulfide magma.

9814204RipleyBblybbleby，因为RE相对于OS在地幔衍生的，玄武岩部分融化和地壳岩石的高RE/OS比中的富集，RE/OSOSOTOPIC系统已被证明是在甲壳层和MATEF-MAFIFED MAGMAS之间的动态相互作用过程中的敏感截止器。 在评估乡村岩石污染的评估中，Re-OS同位素系统作为岩石学示踪剂的应用取决于对污染物岩石中开放或封闭系统行为的适当评估，以及在结晶的强光岩石或硫化物 - 富含硫化物的矿石材料结晶后RE和OS的固定性。 该项目将评估RE和OS在有机丰富的沉积岩石中的分布和同位素特性，接触变质过程中同位素特征的变化以及这些岩石向角式转化的同位素特征以及在硫化物岩石中发现的同位素变化，这是由于乡村岩石同化或释放的流体流体量所产生的。 Duluth Complex和Propererokoic Country Rocks的地质环境提供了一个绝佳的机会，可以通过接触变质和脱水和脱水的过程以及Mafic Magfic岩浆吸收乡村岩石的过程。 Both crustally-contaminated and uncontaminated gabbroic and troctolitic rocks are present in the area of​​ the Babbitt Cu-Ni deposit, and systematic Re-Os analyses will permit an in-depth evaluation of the causes of isotopic variability that may originate as a result of metamorphic and hydrothermal processes in the country rocks, and magmatic processes related to changes in the ratio of silicate magma to sulfide岩浆。