Sandstone, siltstone, argillite, and conglomerate of the Jurassic-age Naknek Formation have been intruded by a small dacite stock, which is surrounded by a sulfide system and alteration halo covering approximately 2 square miles. The prospect contains an estimated resource of 4.5 to 9 million metric tons grading 0.25 percent copper, 0.01 percent molybdenum, and trace gold. Alteration appears to be the classic porphyry type with a potassic core grading outward through phyllic, argillic, and propylitic alteration zones although these may not all be developed fully. Detailed mapping, sampling and drilling (5 holes totaling 1,865 ft) in 19751976. Further exploration in 1979 and 1981. Additional mapping and sampling by the U.S. Geological Survey in 1980 and 1981. Drilling (2 holes totaling 1,000 m) in 2006. The prospect contains an estimated resource of 4.5 to 9 million metric tons grading 0.25 percent copper, 0.01 percent molybdenum, and trace gold.
Study area name
U.S. Geological Survey (2014a); Fields (1977); Wilson (1980)
U.S. Geological Survey National Mineral Resource Assessment Team (2002)