Widstedt (Anvil Creek)

Prospect, Active?

Commodities and mineralogy

Main commodities Au; Sb
Ore minerals arsenopyrite; gold; pyrite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.58
Longitude -165.3975
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Widstedt prospect is at an elevation of about 250 feet in a small drainage on the south flank of Bonanza Hill (elevation 640 feet) and about 500 feet due west of the Snake River road. It is locality 20 of Hummel (1962 [MF 247]) and included in locality 48 of Cobb (1972 [MF 463], 1978 [OFR 78-93]). The map loction is just inside the west-central boundary of section 36, T. 10 S., R. 34 W., Kateel River Meridian.

Geologic setting

Geologic description

The Widstedt prospect lies within or near the Anvil Creek fault and related shear zones that are as much as 120 feet wide. The deposit consists of quartz-calcite veins that contain arsenopyrite, pyrite, and locally stibnite.
The veins commonly cut schist or are localized in shear zones (Collier and others, 1908; Brooks, 1916; Mertie, 1918 [B 662-I, p. 425-449]; Cathcart, 1922). Pyrite and arsenopyrite also are disseminated in schist adjacent to the veins, and some sulfide-rich zones are as much as 15 feet wide. Stibnite lenses with little quartz occur at this prospect and some stibnite ore has reportedly been produced (Mertie, 1918 [B 662-I, p. 425-449]; Cathcart, 1922). Material from a dump next to a water-filled shaft consisted of finely crystalline stibnite associated with pyrite and arsenopyrite in small veinlets cutting quartz and schist. An open cut exposed a 12 foot-wide zone of quartz stringers cut by veinlets of finely crystalline stibnite.
The Anvil Creek fault is a through-going high-angle structure that inthis area juxtaposes different types of graphitic schist and dark graphitic quartzite in this area (Hummel, 1962 [MF 247]). Bedrock is mostly graphitic schist, probably of early Paleozoic protolith age (Hummel, 1962 [MF 247]; Sainsbury, Hummel, and Hudson, 1972 [OFR 72-326]; Till and Dumoulin, 1994; Bundtzen and others, 1994).
Geologic map unit (-165.400103691867, 64.5792345570717)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a) and/or possibly simple Sb deposits (Cox and Singer, 1986; model 27d).
Mineral deposit model number 36a, 27d?
Age of mineralization Mid-Cretaceous; vein cuts schist metamorphosed during the mid-Cretaceous; see NM207.

Production and reserves

Workings or exploration An exploration shaft was filled with water by 1920; some open-cut surface workings are also present (Cathcart, 1922). In 1916, the total length of underground workings on lode gold prospects in Anvil Creek valley was several hundred feet (Mertie, 1918 [B 662-I, p. 425-449]).
Indication of production Yes; small
Production notes A small amount of antimony ore is reported to have been mined from the Widstedt prospect (Mertie, 1918 [B 662-I. p. 425-449]).


MRDS Number A012844; A012845


Till, A.B., and Dumoulin, J.A, 1994, Geology of Seward Peninsula and St. Lawrence Island, in Plafker, G., and Berg, H.C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, v. G-1, p. 141-152.
Reporters C.C. Hawley and Travis L. Hudson
Last report date 7/10/2000