Gunnysack Creek (east of Black Rapids Roadhouse)

Prospect, Inactive

Commodities and mineralogy

Main commodities Au; Sb
Ore minerals gold; stibnite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale C-4
Latitude 63.5291
Longitude -145.8203
Nearby scientific data Find additional scientific data near this location
Location and accuracy The approximate location of this prospect is at an elevation of 2,450 feet on the north side of Gunnysack Creek 0.65 mile east-northeast of the Black Rapids Roadhouse (Rapids Club) or about 1 mile southeast of the Rapids landing strip. It is in the NE1/4SE1/4 section 17, T. 16 S., R. 10 E., Fairbanks Meridian. The location is approximated from a description by Capps (1912) and is accurate within a half-mile. It corresponds to locality 6 in Cobb (1979 [OFR 79-238]) and locality N11 of table 1 in Nokelberg and others (1991).

Geologic setting

Geologic description

At this prospect pyrite and stibnite occur in an iron-stained milky quartz vein as much as 20 feet thick (Capps, 1912). This principal vein strikes S33W and dips about 70NW. In a 30-foot tunnel a stockwork of quartz stringers is parallel to the footwall of the main vein. The veins cut quartz mica schist derived from early to middle Paleozoic metasedimentary rocks. This summary description is from Nokleberg and others (1991). Joesting (1942) reported that the stibnite ore carried $1.5 to $15 (0.075 to 0.75 ounce) in gold per ton.
Geologic map unit (-145.822573644499, 63.5286915634154)
Mineral deposit model Simple Sb deposit (Cox and Singer, 1986; model 27d).
Mineral deposit model number 27d

Production and reserves

Workings or exploration A 30-foot tunnel was driven sometime prior to 1912 following reports of rich gold assays from the veins (Capps, 1912). Further tests proved the gold content too low for profitable extraction, and the claims were abandoned. Joesting (1942) reported that the stibnite ore carried $1.5 to $15 (0.075 to 0.75 ounce) in gold per ton (gold at $20 per ounce ton in 1912) and that the tunnel was driven in 1916, which does not agree with Capps' date.
Indication of production None