Willow Creek Prospect, Fairbanks Mining District, Fairbanks North Star Borough, Alaska, USAi

Regional Level Types
Willow Creek Prospect	Prospect
Fairbanks Mining District	Mining District
Fairbanks North Star Borough	Borough
Alaska	State
USA	Country

Location: Cobb (1972, MF-413), loc. 88; NE1/4 sec. 25, T. 3 N., R. 1 E., of the Fairbanks Meridian. This prospect is situated in the bed of Willow Creek, about 100 yards from its mouth. Willow Creek is a tributary of Cleary Creek.
Geology: This antimony prospect was uncovered during placer mining operations and was described by Henry Joesting in a report to the Alaska Territorial Department of Mines in 1942. The antimony ore occurs as stibnite in a zone of white quartz and gouge that strikes east-west, across the valley of Willow Creek (Joesting, 1942; ATDM PE 49-7). In the hydraulic cut, where the overburden and gravel have been removed, high-grade ore could be traced continuously from the west side of the cut to the creek, a distance of about 75 feet. Ore is also found on the east side of the cut, about 100 feet from the creek. Between these two showings of ore, the zone consists mainly of quartz and gouge, with minor amounts of stibnite and pyrite, and occasionally arsenopyrite. Some pieces of high-grade stibnite found on the surface measured about a foot across. Most of the ore is fine-grained and massive with a minor portion made up of coarse bladed crystals. The higher grade portions contained 56 percent antimony. Small amounts of pyrite and arsenopyrite occur in the lower grade material. The bedrock is mainly a soft, badly weathered mica schist, containing considerable clay. The schist strikes east-west and dips steeply north. Several thin limestone beds were noted. A few of these beds, about 100 feet upstream from the stibnite, contain sphalerite and pyrite. Numerous small veins and lenses of quartz were also noted in the bedrock. Most veins are glassy, but some contain small amounts of pyrite, arsenopyrite, and sphalerite.
Workings: The vein was exposed by a hydraulic cut during placer mining operations.

Commodities (Major) - Sb; (Minor) - Au, Sn, W
Development Status: None
Deposit Model: Stibnite-quartz vein (Cox and Singer, 1986; model 27d).

Other Databases

Link to USGS - Alaska:	LG109

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References