Associated with a quartz diorite pluton that cuts Paleocene- to Eocene-age sedimentary rock of the Tolstoy Formation; the stock and Mo mineralization have been dated at 6 million years (Wilson and others, 1996; Wilkins, 2011). The alteration consists of a barren, potassically-altered core zone, an intermediate zone characterized by pervasive quartz and sericite, and a propylitic outer zone. In 1975, the resource was estimated to be 126 million tons with a grade of 0.403 percent copper and 0.025percent molybdenum; there was said to be potential for an additional 49 million tons of chalcocite-enriched ore. In 2013, the resource was estimated to be 173 million metric tons with a grade of 0.088 g/t Au, 0.35% copper, and 0.02% molybdenum (based on 49 drill holes totaling 9,177 m).
Study area name
U.S. Geological Survey (2014a); Wilkins (2011); Wilson and others (1996); Farrow and Arseneau (2013); Nokleberg and others (1987); Young and others (1997); Singer and others (2008)
U.S. Geological Survey National Mineral Resource Assessment Team (2002)