Eureka Stibnite (Pick claim group)

Mine, Inactive

Commodities and mineralogy

Main commodities Sb
Other commodities Ag; Au; Pb
Ore minerals arsenopyrite; pyrite; stibiconite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MM
Quadrangle map, 1:63,360-scale C-2
Latitude 63.5306
Longitude -150.9518
Nearby scientific data Find additional scientific data near this location
Location and accuracy
The Eureka Stibnite mine is in the canyon of lower Eureka Creek about 0.4 mile above the mouth of the creek. It is at an elevation of about 1800 feet, about 0.25 mile north of the center of section 13, T. 16 S., R. 18 W., Fairbanks Meridian. The location is accurate within about 500 feet.
The site corresponds to number 14 of Bundtzen, Smith, and Tosdal (1976), 140 of Hawley (1978), 16 of Bundtzen (1981), and 33 of Thornsberry, McKee, and Salisbury (1984). The deposit is classified as an unnamed prospect by Cobb (1980 [OFR 80-363]), and is briefly noted in his description of the Eureka Creek placer deposit (1980, number 46).

Geologic setting

Geologic description

The country rocks at the Eureka Stibnite mine are quartz schist with ankeritic interlayers and quartz-chlorite-muscovite schist with graphitic interlayers. The rocks belong to the upper Precambrian Birch Creek Schist (Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 33). The deposit consists of mineralized quartz veins in a fault zone more than 50 feet wide that strikes about N 40 W. The principal vein is near the center of the zone. It is about 3 feet thick and consists of quartz and stibnite, and lesser amounts of arsenopyrite and pyrite. In part, the stibnite and quartz form dendritic intergrowths. Stibnite-rich quartz stringers occur in the zone for a distance up to 50 feet from the central vein. Stibiconite is abundant in the weathered part of the deposit. Assays show up to 0.12 ounce of gold per ton, 0.92 ounce of silver per ton, and 0.12 percent lead (Hawley and Associates, 1978; Thornsberry, McKee, and Salisbury, 1984, v. 2).
The Eureka Stibnite mine produced about 112 tons of stibnite ore. The deposit is similar to those at the Stampede (MM144) and Slate Creek (MM153) mines.
Geologic map unit (-150.954085262261, 63.5300935004618)
Mineral deposit model Simple Sb deposit (Cox and Singer, 1986; model 27d).
Mineral deposit model number 27d
Age of mineralization The deposit is assumed to be Eocene (see record MM091).
Alteration of deposit Oxidation of antimony mineral.

Production and reserves

Workings or exploration The deposit was discovered during the early period of placer mining in the Kantishna district. Prindle (1907) reported stibnite in the placer concentrates of Eureka Creek. The deposit was mined in 1915, 1970, and between 1970 and 1983. The property currently (2001) is inactive and the workings are caved.
Indication of production Yes; small
Production notes About 112 tons of stibnite ore were mined from 1915 to 1983, including 50 tons in 1915 (Bundtzen, 1981); 12 tons in 1970; and 50 tons between 1970 and 1983 (Thornsberry, McKee, and Salisbury, 1984, v. 2). The ore mined in 1970 contained 62 percent antimony.

Additional comments

The mine is in Denali National Park and Preserve.

References