Prospect, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu
Other commodities Fe
Ore minerals azurite; chalcopyrite; hematite; malachite; pyrite
Gangue minerals epidote; quartz

Geographic location

Quadrangle map, 1:250,000-scale TK
Quadrangle map, 1:63,360-scale B-5
Latitude 62.3575
Longitude -149.0238
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Talkeetna prospect is at an elevation of about 4,400 feet at the head of Prospect Creek, a tributary of the East Fork, Iron Creek. It is in the SE1/4NE1/4 sec. 11, T. 26 N., R. 2 E., Seward Meridian. The location is accurate to within 1/2 mile.

Geologic setting

Geologic description

The Talkeetna prospect consists of: 1) greenstone with replacement bodies of specular hematite and quartz; 2) greenstone breccia with clasts that are partially replaced by pyrite and chalcopyrite in a matrix that contains hematite, chalcopyrite, and quartz; and 3) an east-west shear zone with quartz veinlets that contain pyrite, chalcopyrite, and hematite (Capps, 1919 [B 692]). Amygdules in the greenstone are filled with epidote. Mineralization parallels the shear zone which is up to 30 feet thick and at least several hundred feet long. A conspicuous gossan contains copper carbonates (Capps, 1919 [B 692]). Capps reported samples that contain up to 8 percent copper. Csejtey and Miller (1978) collected float samples that contain small amounts of gold. U.S. Bureau of Mines grab samples contain up to 85,000 parts per million copper and 9.6 parts per million silver; 5-foot chip samples contain up to 25,000 parts per million copper and 5.4 parts per million silver (Fechner, 1986).
A number of open cuts and trenches have been excavated through the gossan. As of January 1, 2000, Cominco held a block of approximately 25 state claims covering this and adjacent prospects (Northern Associates Inc., written communication, 2001).
Geologic map unit (-149.026021707156, 62.3570062896314)
Mineral deposit model Basaltic Cu (Cox and Singer, 1986; model 23)
Mineral deposit model number 23
Alteration of deposit Epidote alteration; oxidation of copper minerals.

Production and reserves

Workings or exploration A number of open cuts and trenches have been excavated through the gossan. Capps (1919, p. 203) reported samples with up to 8 percent copper. Examination and sampling by the U.S. Geological Survey and U.S. bureau of Mines (Csejtey and Miller, 1978; Fechner, 1986).
Indication of production None

Additional comments

MAS/MILS number 20760012.


MRDS Number A106279


Reporters R.K. Rogers (U. S. Geological Survey contractor)
Last report date 10/1/2002