North Silver West

Prospect, Undetermined

Commodities and mineralogy

Main commodities Ag; Pb; Zn
Ore minerals galena; pyrite; sphalerite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale PE
Quadrangle map, 1:63,360-scale C-1
Latitude 56.515
Longitude -132.0484
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is about 1.0 mile southwest of Mount Waters at an elevation of about 4,220 feet; it is about 0.5 north-northeast of the center of section 7, T. 62 S., R. 85 E. The location is accurate and it is Map No. 94 of Still and others (2002).

Geologic setting

Geologic description

The rocks in the prospect area are part of a belt of Mesozoic or Paleozoic sedimentary and volcanic rocks that have been metamorphosed to schist and gneiss. The belt is about 1 1/2 mile wide and strikes northwest (Brew, 1997; George and Wyckoff, 1973). The metamorphic rocks are bounded on the east by a thick, regionally extensive, 60 to 70 Ma tonalite sill and on the west by a 90 Ma granodiorite pluton (Brew, 1997 Still and others, 2002). On the north side of Groundhog Basin about a mile southwest of this prospect, the metamorphic rocks are intruded by a 16.3 Ma biotite 'tin' granite pluton. The granite is probably the source of the numerous rhyolite dikes and sills that extend from it and the mineralization in the area (Newberry and Brew, 1989).
In the late 1950s, Moneta Porcupine Company staked claims in the area but subsequently dropped them. William Huff and James Fucas continued prospecting in the area and Huff discovered the North Silver West prospect in 1963. Their claims were optioned by the Bunker Hill Mining Company in 1965 and they dug several pits on the mineralization. They dropped the claims at the end of the field season and the property was optioned by a succession of companies, Humble Oil and Refining Company, El Paso Natural Gas Company and AMAX Exploration Inc., through 1981. An adit driven early in the history of the prospect extended only a few feet into the rock. Still and others (2002) sampled the prospect during a Bureau of Land Management mineral assessment of the area.
The North Silver West prospect is associated with a fault zone up to 10 feet thick that strikes N20-40E and dips 50-89 degrees southeast. The footwall of the fault schist with 0.5-to-4-foot-thick, irregular lenses and pods of quartz with massive and disseminated pyrite, galena, and sphalerite. The fault zone, as now exposed extends for about 185 feet. Samples collected by Still and others (2002) across 0.5 to 4.9 feet of the mineralization contained 31.3 to 79.46 parts per million (ppm) silver, 1,795 ppm to 33.47 percent lead, and from 2,734 ppm to 9.8 percent zinc.
Geologic map unit (-132.05008121078, 56.5146659065549)
Mineral deposit model Banded Ag-Cu-Sn-Pb-Zn tabular replacement bodies, veins, and stringers.
Age of mineralization Probably related to a nearby 16.3 Ma biotite granite pluton.
Alteration of deposit None specifically noted.

Production and reserves

Workings or exploration In the late 1950s, Moneta Porcupine Company staked claims in the area but subsequently dropped them. William Huff and James Fucas continued prospecting in the area and Huff discovered the North Silver West prospect in 1963. Their claims were optioned by the Bunker Hill Mining Company in 1965 and they dug several pits on the mineralization. Bunker Hill dropped the claims at the end of the field season and the property was optioned by a succession of companies through 1981: Humble Oil and Refining Company, El Paso Natural Gas Company, and AMAX Exploration Inc. Still and others (2002) sampled the prospect during a Bureau of Land Management mineral assessment of the area.
Indication of production None
Reserve estimates None.

References

References

Reporters D.J. Grybeck (Port Ludlow, WA)
Last report date 3/4/2008