Stipek And Kotovic (divide between Glacier and Rock Creeks)

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; W
Ore minerals arsenopyrite; galena; gold; pyrite; scheelite
Gangue minerals albite; quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.6029
Longitude -165.4125
Nearby scientific data Find additional scientific data near this location
Location and accuracy The approximate location of the Stipek and Kotovic prospect is between 150 and 350 feet elevation on the south flank of Mount Byrntson. The map location is at 300 feet elevation on the divide between Glacier and Rock Creeks, in the east-central part of section 23, T. 10 S., R. 34 W., Kateel River Meridian. It is locality 7 of Hummel (1962 [MF 247]), who erroneously called it the Hot Air prospect. It is included with other Rock Creek area prospects in locality 43 of Cobb (1972 [MF 463]; 1978 [OFR 78-93]) and is one of three prospects numbered 14 by Cathcart (1922, figure 18 and p. 241). The location is accurate to about 500 feet.

Geologic setting

Geologic description

Massive quartz veins and mineralized schist subcrop on the divide between Glacier Creek and Rock Creek. The general trend of the deposit is northeast, more or less parallel to the ridge. The prospect was developed around 1916 by Stipek and Kotovic (Mertie, 1918). Mertie (1918) reported the occurrence of scheelite at this location and thought the deposit was similar to that of Sophie Gulch (NM208). Cathcart (1922, figure 32, p. 241) found a quartz-feldspar vein containing pyrite and arsenopyrite exposed in a trench. The deposit was again prospected from 1985 to 1995 in the period of exploration initiated by geologist R.V. Bailey. The prospect is within the extensive gold-antimony soil geochemical anomaly identified by BHP in 1990 and by Kennecott Exploration Company in 1994 and 1995. This anomaly is essentially continuous on the lower slopes east of Snake River from Glacier Creek (NM220) to Lindblom Creek (NM205) and discontinuous to Goodluck Gulch (NM202). The prospect was trenched and drilled by Placer Dome in 1987 and 1988. Their exploration showed that this deposit is low grade and characterized by massive bull quartz veins, extensive albitization, and introduction of arsenopyrite. Some white vein quartz contains less than 1 percent galena. Exposures are poor; bedrock is mainly chloritic mica-quartz schist and some graphitic quartz schist, generally related to the chlorite-rich metaturbidite unit of Bundtzen and others (1994).
Geologic map unit (-165.415106016575, 64.6021344942484)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Probably mid-Cretaceous or younger; see NM207.
Alteration of deposit Albitization and sulfidization of schist.

Production and reserves

Workings or exploration The area was prospected by Stipek and Kotovic before 1916 by shallow pits and shafts (Mertie, 1918 [B 662-I, p. 425-449]; Cathcart, 1922). Renewed exploration began in 1985; Placer Dome drilled several shallow holes in the area in 1987-88.
Indication of production Undetermined
Production notes Some scheelite may have been produced in 1916.