Unnamed Prospect (ARDF - HE056; head of Ohio Creek), Valdez Creek Mining District, Matanuska-Susitna Borough, Alaska, USAi

Regional Level Types
Unnamed Prospect (ARDF - HE056; head of Ohio Creek)	- not defined -
Valdez Creek Mining District	Mining District
Matanuska-Susitna Borough	Borough
Alaska	State
USA	Country

Stream sediment samples taken from area adjacent to granitic stock suggest undiscovered vein deposits in country rock.
Location: The prospect is at an elevation of about 3,500 feet at the northwest edge of the glacial moraine at the head of Ohio Creek. The site is on the boundary of secs. 7 and 18, T. 20 S., R. 12 W., of the Fairbanks Meridian. The accuracy of the location is within 0.5 mile. This is locality 18 of Cobb (1978, OFR 78-1062).
Geology: The host rock at this prospect is Upper Cretaceous to Upper Jurassic, intensely deformed and locally highly metamorphosed flysch which is several thousand meters thick (Wilson and others, 1998). The strata have been intruded by a granitic stock 1 mile long by 0.5 mile wide. The deposit consists of tourmaline and muscovite greisen and quartz-arsenopyrite veins. The greisen is up to 10 feet thick. It adjoins a biotite-rich inclusion at least 150 feet long, and locally contains 0.1% Sn (Hawley and others, 1969). The upper 3 to 10 feet of the granitic body contains pegmatitic quartz-arsenopyrite veins that parallel the contact with country rock (Hawley and Clark, 1974). The veins also contain wodginite, a manganese-tin-niobium oxide, and 1.25% tungsten, 147 ounces of silver per ton and traces of tin, lead, and copper (Hawley and others, 1978).
Workings: There has been minor surface exploration. Veins contain wodginite, a manganese-tin-niobium oxide, and 1.25% tungsten, 147 ounces of silver per ton and traces of tin, lead, and copper (Hawley and others, 1978).
Age: Late Cretaceous or younger.
Alteration: Greisenization.

Commodities (Major) - Ag, Sn; (Minor) - Au, Cu, Nb, Ta, W, Zn
Development Status: None
Deposit Model: Sn greisen (Cox and Singer, 1986; model 15c)

Other Databases

Link to USGS - Alaska:	HE056

Other Regions, Features and Areas containing this locality

References