A Quantitative Method for Measuring Temperature-time Histories in Hydrothermal Magmatic Ore Systems

热液岩浆矿石系统温度-时间历史测量的定量方法

• 批准号: 1220252
• 负责人: Drew Coleman
• 金额: $ 21.7万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1220252&HistoricalAwards=false
• 关键词: Quantitative; Method; Measuring; Temperature; time

In 2010, the United States produced over $800 million of molybdenum oxide, and the demand for molybdenum as an alloying agent in high-grade steel will likely increase as global economies recover. The majority of the world's molybdenum reserves are contained within porphyry copper (±molybdenum) and porphyry molybdenum (±copper) deposits. Although porphyry molybdenum deposits are often volumetrically smaller than porphyry copper systems, they are still a significant source of molybdenum owing to higher ore grades. Understanding porphyry molybdenum deposition is important for accurate predictions of spatial and temporal ore distribution during exploration. The timing and duration of molybdenum mineralization relative to associated magmatism will be investigated. The study will lend insight into the complex variations of ore grade, alteration geochemistry, and magmatic-hydrothermal textures observed within porphyry molybdenum ore systems.Detailed uranium/lead zircon (±titanite) and argon/argon biotite (±hornblende) dating of plutonic rocks associated with porphyry molybdenum deposits in the western US will be obtained. In addition, rhenium/osmium molybdenite dates, and fluid trapping temperatures for molybdenite in quartz veins from economically important deposits will be determined. These data will be used to establish precise temperature-time histories of the deposits and the timing of mineralization within the thermal maturation of the magma system. This information should be useful in enhancing exploration for molybdenum - an increasingly valuable international commodity. The results of this work should 1) enable better understanding of porphyry mineralization in light of new hypotheses regarding the incremental assembly of homogeneous plutons, and 2) further development of combined rhenium/osmium geochronology and fluid inclusion thermometry as a broadly applicable thermochronologic tool.

2010年，美国生产了超过8亿美元的氧化钼，并且随着全球经济的恢复，对高级钢铁合金剂的钼的需求可能会增加。世界大多数钼储量都包含在斑岩铜（±钼）和斑岩钼（±铜）沉积物中。尽管斑岩钼沉积物通常比斑岩铜系统小，但由于较高的矿石等级，它们仍然是钼的重要来源。了解斑岩钼沉积对于准确预测探索过程中的空间和临时矿石分布非常重要。将研究相对于相关的岩浆作用的钼矿化的时间和持续时间。 The study will lend into the complex variations of ore grade, alteration geochemistry, and magmatic-hydrothermal textures observed within porphyry molybdenum ore systems.Detailed uranium/lead zircon (±titanite) and argon/argon biotite (±hornblende) dating of plutonic rocks associated with porphyry molybdenum deposits in the western US will be obtained.此外，将确定从经济重要的沉积物中的石英静脉中钼的日期和钼的流体捕获温度。这些数据将用于在岩浆系统的热成熟中建立沉积物的精确温度历史和矿化时间。该信息对于增强钼的探索应该很有用 - 钼越来越有价值的国际商品。这项工作的结果应为1）鉴于有关均匀岩石的增量组装的新假设，以及2）进一步发展rhen液/osmium地球人数和流体融合体温度法作为一种广泛适用的热量调节学工具，可以更好地了解斑岩矿化。