9205646 Kesler This is a study of several important features of greenstone gold deposits, the largest hypogene gold deposits in the world. Research will be on the Porcupine district, Ontario, where high-grade gold ore is well developed and where we have collected over 400 barren veins from an area of 2000 km2 surrounding the deposits. Work will involve study of the structural setting of high-grade ore, fluid inclusion petrography and microthermometry of ore and barren veins, and inclusion gas, stable isotope and radiogenic isotope analyses of barren and high-grade veins. The research will include analysis of inclusions in gold and related minerals, and an attempt to obtain isotopic ages on minerals from different pasts of sheeted veins to determine the period over which the deposits formed. The results are expected to provide insights into the source of the gold-forming fluid and its relation to the evolution of Archean greenstone terrains, as well as structural and geochemical parameters that could guide exploration for these deposits.
