Silver King

Prospect, Active

Commodities and mineralogy

Main commodities Ag; Au; Cu
Other commodities Bi; Co; Sb
Ore minerals arsenopyrite; chalcopyrite; pyrite; pyrrhotite; stibnite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale HE
Quadrangle map, 1:63,360-scale B-6
Latitude 63.26
Longitude -149.55
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Silver King prospect is located on the eastern side of Colorado Creek in the northern half of sections 19 and 24, T. 19 S., R. 10 W., of the Fairbanks Meridian. The location is accurate to within 0.5 mile. The Silver King prospect is not the same as the Silver King mine shown on the Healy A-6 1:63,360-scale topographic sheet.

Geologic setting

Geologic description

Thick Quaternary glacial deposits and Upper Tertiary sedimentary strata cover the bedrock in this area. The country rocks in the area of the Silver King prospect consist of Upper Jurassic to Upper Triassic(?) crystal tuff, argillite, chert, graywacke, and limestone that are intruded by Upper Cretaceous quartz diorite porphyry stocks and dikes (Wilson and others, 1998). Intrusion of the dikes and quartz-sulfide mineralization are localized along the nearby Chulitna fault. The Silver King deposit includes: tactite (skarn) replacement bodies; auriferous arsenopyrite-chalcopyrite quartz veins; stibnite-gold-silver veins; silver-lead-zinc veins; and as breccia pipes associated with porphyry stock and dikes. Sporadic mineralization is present over a 2,000 feet by 800 feet area. (Hawley and Clark, 1974).
Hawley and Clark (1974) reported the following sample analyses. A massive sulfide pod in skarn contained 8.3 ounces of gold per ton. An arsenopyrite-rich vein contained 50 ppm silver, 200 ppm gold, 700 ppm cobalt, 1,500 ppm copper, 200 ppm lead, 500 ppm antimony, 200 ppm zinc, more than 1,000 ppm bismuth and more than 10,000 ppm arsenic. A stibnite-rich vein contained 10 ppm silver, 23 ppm gold, 200 ppm copper, 300 ppm lead, 1,500 ppm zinc, 7,000 ppm arsenic and more than 10,000 ppm antimony. Salisbury and Dietz (1984) reported the following: arsenopyrite veins returned assay values of 0.85 ounces of silver per ton, 0.87 ounces of gold per ton and 0.44% cobalt; and stibnite-bearing veins contained 0.12 ounces of silver per ton and 0.29 ounces of gold per ton. The Silver King deposit is part of a northeast trending mineralized zone that includes the Liberty (HE028), Lucrata (HE029) and Eagle (HE030) prospects.
Geologic map unit (-149.552290246969, 63.2595283784348)
Mineral deposit model Polymetallic vein, Cu-Au porphyry, Cu skarn, and Simple Sb veins (Cox and Singer, 1986; models 22c, 20c, 18b, and 27d)
Mineral deposit model number 22c, 20c, 18b, 27d
Age of mineralization Similar sulfide-bearing intrusive rocks and veins in the district have been dated as Late Cretaceous (Swainbank and others, 1977), but Au-Ag-stibnite and Ag-Pb-Zn veins could be younger (Early Tertiary?).
Alteration of deposit Skarn formation widespread; porphyry-type alteration is also reported.

Production and reserves

Workings or exploration
Surface workings, mostly trenches and pits. Site-specific geophysical surveys noted in literature and probably drill testing, but specific data are not available.
Hawley and Clark (1974) reported the following sample analyses. A massive sulfide pod in skarn contained 8.3 ounces of gold per ton. An arsenopyrite-rich vein contained 50 ppm silver, 200 ppm gold, 700 ppm cobalt, 1,500 ppm copper, 200 ppm lead, 500 ppm antimony, 200 ppm zinc, more than 1,000 ppm bismuth and more than 10,000 ppm arsenic. A stibnite-rich vein contained 10 ppm silver, 23 ppm gold, 200 ppm copper, 300 ppm lead, 1,500 ppm zinc, 7,000 ppm arsenic and more than 10,000 ppm antimony. Salisbury and Dietz (1984) reported the following: arsenopyrite veins returned assay values of 0.85 ounces of silver per ton, 0.87 ounces of gold per ton and 0.44% cobalt; and stibnite-bearing veins contained 0.12 ounces of silver per ton and 0.29 ounces of gold per ton.
Indication of production Undetermined

References

MRDS Number A011334

References

Salisbury and Dietz, Inc., 1984, 1983 mineral resource studies--Kantishna Hills and Dunkle Mine areas, Denali National Park and Preserve, Alaska: U.S. Bureau of Mines, Contract No. S0134031, 1,080 p.
Reporters N. Van Wyck (Stevens Exploration Management Corporation); F.H. Wilson (USGS)
Last report date 3/28/2016