Geologic descriptionThis prospect is a zone of intense hydrothermal alteration and brecciation in volcanic rocks of the upper Paleozoic, Tetelna Volcanics (Richter, 1973, 1976). The breccia is cemented by quartz containing minor chalcopyrite, pyrite and galena. Small unaltered to limonite-stained, porphyry intrusions cut the volcanic rocks (Richter and Matson, 1970 [OFR 70-276]). Rock samples from the area contain up to 0.9 parts per million (ppm) gold, 1,000 ppm lead, and 200 ppm copper (Richter and Matson, 1970 [OFR 70-276]). |
Geologic map unit |
(-142.769127459615, 62.1799100497091) |
Mineral deposit model |
Polymetallic veins? (Cox and Singer, 1986; model 22c) |
Mineral deposit model number |
22c |
Age of mineralization |
Cretaceous or Tertiary. The host rocks to the mineralization are late Paleozoic, but the porphyries are considered to be Tertiary (Richter, 1973, 1976). The mid-Cretaceous Nabesna pluton, spatially associated with porphyry copper deposits like that at Orange Hill (NB043), outcrops about 2 miles to the north. |
Alteration of deposit |
Silicification and possibly other types of alteration. |