187Re-187Os Study of the Timing and Duration of Archean Au Mineralization

187Re-187Os太古代金矿化时间和持续时间的研究

• 批准号: 9706185
• 负责人: John Morgan
• 金额: $ 16.99万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706185&HistoricalAwards=false
• 关键词: 187Re; 187Os; Study; Timing; Duration

9706185 Morgan Ore deposits do not form randomly throughout the EarthOs history, but develop in response to the coming together of very specific geologic conditions, largely controlled by plate tectonics and the melting of rocks in the EarthOs deep crust and underlying mantle layer. Knowing the three-dimensional regional and local geology in combination with the precise ages for geologic events that led to mineralization, markedly improves the scientistOs ability to predict areas where buried ore deposits might be present. In this study, the 187Re-187Os isotopic system will be used for dating mineral pairs such as pyrite and molybdenite in order to elucidate the timing of gold mineralization that, in turn, help constrain the mechanism for discerning multiple magmatic and hydrothermal events at any single locality. This project will focus on gold deposits formed early in EarthOs history, some 2.0 to 3.0 billion years ago during Archean time, and it is expected that the results will shed light on the controversy surrounding the timing and duration of world-renowned gold mineralization at that time.

摩根矿床不是在地球历史上随机形成的，而是在非常特殊的地质条件下形成的，这些地质条件主要受板块构造和地球深部地壳和下地幔层岩石熔融的控制。 了解三维区域和局部地质，并结合导致成矿作用的地质事件的精确年龄，可以显著提高科学家预测可能存在埋藏矿床的地区的能力。 在这项研究中，187 Re-187 Os同位素系统将被用于定年矿物对，如黄铁矿和辉长岩，以阐明金矿化的时间，反过来，有助于限制识别多个岩浆和热液事件在任何一个单一的位置的机制。 该项目将侧重于地球历史早期形成的金矿，大约在20亿至30亿年前的太古代，预计其结果将有助于阐明当时围绕世界著名金矿化的时间和持续时间的争议。