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.