Transport, Concentration, and Deposition of Precious Metals in Layered Gabbros During Continental Rifting

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Recent discoveries of gold and platinum group (PGE) mineralization in Eocene layered gabbros of East Greenland demonstrate that physical and chemical processes associated with the transition from continental to oceanic rifting can concentrate precious metals in the Earth's crust. One of these gabbros, the Kap Edvard Holm Complex, exhibits an unusual combination of features related to stratiform precious metal mineralization. An understanding of these processes requires detailed field, petrologic, isotopic, and chemical analyses, combined with theoretical analysis of the thermodynamic and transport characteristics of magma-hydrothermal systems. The long-term plans for this research program inviove using these techniques to provide new insights into the nature of processes controlling: 1) precious metal concentration during gabbro crystallization; and 2) precious metal transport and deposition in gabbro-hosted hydrothermal systems. A specific objective of the research will be evaluation of various hypotheses that may explain the unusually high ratio of precious metal to sulfide that is characteristic of this deposit. Investigation of the processes responsible for mineralization in the East Greenland gabbros is potentially of great importance to understanding the global distribution of precious metals and to formulating future mineral exploration strategies. The present award will enable him to get started while he is formulating a plan to achieve the long-term goals.