Pyrite and chalcopyrite occur in quartz veinlets and as disseminations in monzonite and monzonite porphyry of the mid-Cretaceous-age Klein Creek pluton near its contact with Jurassic or Cretaceous siliciclastic rocks; the associated hydrothermal alteration zone extends across this contact. The deposit has a central 200- by 700-meter zone of potassium feldspar, actinolite, and magnetite alteration, and a 800- by 1,500-meter outer zone of unspecified hydrothermal alteration; estimated to contain 60 million tons with an average grade of 0.20 percent copper and very low amounts of molybdenum. Surface exploration and some diamond drilling.
Study area name
U.S. Geological Survey (2014a); Richter, Lanphere, and Matson (1975); Singer and others (2008); Young and others (1997)
U.S. Geological Survey National Mineral Resource Assessment Team (2002)
Young, L.E., St. George,P., and Bouley, B.A., 1997,Porphyry copper deposits in relation to the magmatic history and palinspastic restoration of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral deposits of Alaska: Economic Geology Monograph 9, p. 306333.