Wicked Falls

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities As
Ore minerals arsenopyrite; gold; pyrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale PA
Quadrangle map, 1:63,360-scale D-4
Latitude 56.96885
Longitude -135.08549
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Wicked Falls prospect is at an elevation of about 970 feet adjacent to the creek between Pinta Lake and the head of Silver Bay. The prospect is about 0.2 mile south of the center of section 33, T. 56 S., R. 65 E. The surface and underground workings are shown on figure 27 of Bittenbender and others (1999).

Geologic setting

Geologic description

This deposit is one of many of similar deposits (PA002 to PA018) scattered over an area of about 6 square miles at the head of Silver Bay (Bittenbender and others, 1999). The deposits are gold-quartz veins with sparse sulfides, usually only pyrite and arsenopyrite. Samples that have been analyzed with modern methods usually show anomalous arsenic even if arsenopyrite is not identified in the rocks, and several parts per million mercury. The veins are often parallel to the bedding of the host rock which is graywacke and argillite of the Sitka Graywacke of Cretaceous age (Loney and others, 1975). Many of the so-called veins in the early literature are actually fault zones with lenses of quartz or concentrations of quartz stringers along the fault zone. Prospecting began in the area in 1871. The Stewart Mine (PA012) was located in 1872 and it was the first lode-gold mine in Alaska. The Silver Bay area has been prospected intermittently to the present but the veins are relatively small and most are low grade. The area has produced relatively little gold, many of the properties have not been active since before 1900, and there has been no production since the early 1940s.
The only record of the Wicked Falls prospect is on a map of the Edgecumbe Exploration Company that is cited in Bittenbender and others (1999). The map shows two tunnels on the property but Bittenbender and others (1999) could find only a 17-foot adit. In the adit, discontinuous quartz veins up to 1.8 feet thick occurs adjacent to a fault between graywacke and slate. The veins pinch and swell and consist mainly of milky quartz. Minor pyrite and arsenopyrite occur along the edge of shale partings in the vein and in sheared slate. The richest sample was hand picked and contained 280 parts per billion gold. There is no indication of production.
Geologic map unit (-135.087252939034, 56.9684833616973)
Mineral deposit model Low-sulfide, gold-quartz vein (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Cretaceous or younger based on the age of the host rocks.

Production and reserves

Workings or exploration The only working is a 17-foot adit.
Indication of production None
Reserve estimates None.
Production notes Probably none.

Additional comments

MAS number: 0021160029.

References

References

Bittenbender, P., Still, J.C., Maas, K., and McDonald, M., Jr., 1999, Mineral resources of the Chichagof and Baranof Islands area, southeast Alaska: Bureau of Land Management, BLM-Alaska Technical Report 19, 222 p.
Reporters Donald J. Grybeck (U.S. Geological Survey)
Last report date 2-Jan-05