Magmatic and Hydrothermal Processes in Porphyry Copper Deposits Below 3km Depth

3km以下斑岩铜矿床的岩浆和热液过程

• 批准号: 9418931
• 负责人: John Dilles
• 金额: $ 6.67万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-01 至 1998-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9418931&HistoricalAwards=false
• 关键词: Magmatic; Hydrothermal; Processes; Porphyry; Copper

9418931 Dilles The origin of porphyry copper mineralization has been broadly related to magmatic hydrothermal fluids that evolve during crystallization of upper crustal, granitic magma chambers. The research will provide critical geochemical data from porphyry copper granites that are exposed in cross- section from 1 to 6 km depth (e.g. the Yerington district, Nevada). The data will provide a field laboratory test of the current theoretical and experimental models of granite crystallization and evolution of highly saline, copper- and sulfur-rich fluids that precipitated ores. The research will emphasize analysis of copper, sulfur, zinc, and copper contents of granite biotite, magnetite, hornblende, and sulfides (pyrite, chalcopyrite). Analyses will be done by electron microprobe and ion microprobe, allowing quantification of contents to the one part-per-million level. The behavior of the trace elements can then be used to estimate at what depths and when during crystallization that granites reached water saturation and lose copper and sulfur. The isotopic and compositional data will allow quantification of the importance of the non-magmatic fluids as source of ore components.

斑岩型铜矿成矿的成因广泛与上部地壳花岗质岩浆房结晶过程中演化的岩浆热液有关。该研究将提供暴露在1 - 6公里深度剖面上的斑岩铜花岗岩的关键地球化学数据（如内华达州耶林顿地区）。这些数据将对目前的花岗岩结晶和高盐、富铜和富硫流体沉淀矿石的演化理论和实验模型进行实地实验室检验。这项研究将着重分析花岗岩黑云母、磁铁矿、角闪石和硫化物（黄铁矿、黄铜矿）中铜、硫、锌和铜的含量。分析将由电子探针和离子探针完成，允许定量的内容到百万分之一的水平。微量元素的行为可以用来估计在结晶过程中，花岗岩在什么深度和什么时候达到水饱和并失去铜和硫。同位素和成分数据将有助于量化非岩浆流体作为矿石成分来源的重要性。