Unnamed (east of Caribou Mountain)

Prospect, Inactive

Commodities and mineralogy

Main commodities Au; Cu; Mo
Other commodities Pb; Zn
Ore minerals chalcopyrite; covellite; molybdenite; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale HU
Quadrangle map, 1:63,360-scale A-6
Latitude 66.1809
Longitude -155.8346
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is east of Caribou Mountain, centered along the ridge that separates Dry Creek and Ida Gulch. The prospect is at an elevation of about 1,600 feet, about 3.2 miles east-northeast of the summit of Caribou Mountain and 3 miles west of Hogatza. The location is accurate within one-half mile.

Geologic setting

Geologic description

Miller and Ferrians (1968) collected a grab sample of pyrite-bearing quartz that contains 2.4 ppm gold, 300 ppm copper, 150 ppm lead, and 300 ppm zinc. Sediment samples from streams draining the intrusive contact are anomalous in Pb and Cu (Miller and Ferrians, 1968). Nokleberg and others (1996) subsequently described the deposit as quartz veins and a quartz stockwork in Upper Cretaceous monzonite porphyry and Lower Cretaceous-Upper Jurassic andesitic volcanic rocks. The veins and stockwork contain chalcopyrite, pyrite, and traces of molybdenite and covellite. The monzonite porphyry is altered to a phyllic-argillic-propylitic assemblage, which is distributed concentrically around the core of the intrusive. Samples contain up to 2.0% copper, 0.2% molybdenum, and 2.4 grams of gold per ton. Nokleberg and others (1996) interpret the prospect as a porphyry copper (-gold) deposit.
Geologic map unit (-155.837251574696, 66.1803379202464)
Mineral deposit model Porphyry Cu-Au? (Cox and Singer, 1986; model 20c?).
Mineral deposit model number 20c?
Age of mineralization The Zane Hills pluton is Cretaceous based on a K/Ar date of 81 Ma (Miller and others, 1966).
Alteration of deposit A phyllic-argillic-propylitic alteration assemblage is distributed concentrically around the core of a monzonitic intrusive.

Production and reserves

Workings or exploration Surface sampling.
Indication of production None

References

References

Hollister, V.F., 1978, Geology of the porphyry copper deposits of the Western Hemisphere: Society of Mining Engineering, American Institute of Mining, Metallurgy, and Petroleum Engineers Inc., 218 p.
Nokleberg, W.J., Bundtzen, T.K., Brew, D.A., and Plafker, G., 1995, Metallogenesis and tectonics of porphyry copper and molybdenum (gold, silver) and granitoid-hosted gold deposits of Alaska, in Schroeter, Tom, ed., Porphyry deposits of the northwestern Cordillera: Canadian Institute of Mining and Metallurgy Special Volume 44, p. 103-141.
Reporters J.M. Britton (Anchorage)
Last report date 8/1/2002