Won - South

Prospect in Alaska, United States with commodities Silver, Tin, Arsenic, Copper, Lead, Antimony, Tungsten, Zinc

Geologic information

Identification information

Deposit ID 10307775
Record type Site
Current site name Won - South
Alternate or previous names Prospect Pit, Dog Day, Gash, Tin Ridge

Geographic coordinates

Geographic coordinates: -155.71999, 63.48147 (WGS84)
Relative position The Won-South Prospect is located in an inclined saddle on a south facing slope of a small but locally prominent 2,920 foot high mountain range in Section 23, T. 23 S., R. 16 E., of the Kateel River Meridian. The property is at an elevation of 2,350 feet (717 m). The reporter briefly visited the site in 1984.
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Geographic areas

Country State
United States Alaska


Commodity Importance
Silver Primary
Tin Primary
Arsenic Secondary
Copper Secondary
Lead Secondary
Antimony Secondary
Tungsten Secondary
Zinc Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Cassiterite Ore
Chalcopyrite Ore
Sphalerite Ore
Tetrahedrite Ore
Axinite Gangue
Quartz Gangue
Tourmaline Gangue


  • (Local) Sericite-quartz in intermediate dikes.

Mineral occurrence model information

Model code 77
USGS model code 20b
Deposit model name Sn-polymetallic vein

Nearby scientific data

(1) -155.71999, 63.48147

Comments on the geologic information

  • Geologic Description = The Won - South prospect is one of several argentiferous and stanniferous prospects in a small but prominent mountain upland 10 miles (15 km) east of the Cripple Creek Mountains. The Won-South prospect consists of four or more, northwest trending, breccia-vein structures that cut tourmaline-axinite and quartz-altered hornfels (Burleigh, 1992; Bundtzen and Miller, 1997). The veins strike North 45 degrees West, and dip steeply both in northeast and southwest directions. The largest tin-silver bearing vein at the Won-South prospect is the Dog Day and Gash veins, which could be traced for strike lengths of up to 3,500 feet (1,067 m). Tin and silver values occur in brecciated hornfels with cassiterite matrix, cassiterite-sulfide druse on fracture surfaces, in open space crackle breccias, and as disseminated cassiterite in quartz veins (Burleigh, 1992, BMOFR 85-92). Host lithologies are thermally altered (hornfels) of shallow marine-to-nonmarine facies of the Upper Cretaceous Kuskokwim Group. The thermal effects are caused by an underlying plutonic body that is manifested in the prospect area by fine grained, northwest trending intermediate dikes. Although some tin was found in the dikes, all significant mineralization thus far found is in the hornfels. Age of mineralization is inferred to be Late Cretaceous-early Tertiary based on age range of plutons in Kuskokwim Mineral belt (Bundtzen and Miller, 1997). In 1984, Anaconda Minerals Company completed two diamond drill holes into the Dog Day and Gash veins and encountered up to 6.90 percent tin and 3.3 ounces/ton silver and highly anomalous antimony, lead, arsenic, copper, and tungsten over unknown widths.
  • Age = Late Cretaceous-early Tertiary (inferred) based on age range of plutons in Kuskokwim Mineral belt (Bundtzen and Miller, 1997).

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Active

Mining district

District name Innoko

Comments on the reserve resource information

  • Reserves = Utilizing Anaconda Minerals exploration data and their own surface sampling, Burleigh (1992, BMOFR 85-92) and Bundtzen and Miller (1997) indicate that the Dog Day-Gash Vein system contains 981,875 tons (890,757 tonnes) of ore grading 1.03 percent tin. The average grade for silver, copper, tungsten and other commodities was not calculated.

Comments on the workings information

  • Workings / Exploration = A data release of the U.S. Geological Survey AMRAP study of the Medfra quadangle (King and others, 1980, 1983b; Patton and others, 1980) reported anomalous tin, tungsten, bismuth, lead, silver, and arsenic in stream sediment and pan concentrate samples from creeks draining the project area. In 1983 Duval Corporation and Anaconda Minerals Inc. followed up on these anomalies and discovered the Won-South lode system. In 1984, Anaconda Minerals completed at least two diamond drill holes into the Dog Day and Gash Veins. Drilling encountered up to 6.9 percent tin and 3.3 ounces/ton silver, and anomalous antimony, lead, arsenic, copper, and tungsten over an undisclosed width. Online Exploration Services, Anchorage, Alaska, continued exploration activities in 1997.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MD024

Bibliographic references

  • Deposit

    Patton, W.W., Jr., Moll, E.J., Dutro, J.T., Jr., Silberman, M.L., and Chapman, R.M., 1980, Preliminary geologic map of Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-A, 1 sheet, scale l:250,000.

  • Deposit

    King, H.D., Tripp, R.B., O'Leary, R.M., and Cooley, E.F., 1983, Distribution and abundance of copper, lead, and zinc in nonmagnetic and moderately magnetic heavy-mineral- concentrate, minus-80-mesh stream-sediment, and ash of aquatic-bryophyte samples, Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-I, 6 sheets, scale 1:250,000.

  • Deposit

    Burleigh, R.E., 1992, Tin mineralization at the Won prospect, west-central Alaska: U.S. Bureau of Mines Open-File Report 85-92, 19 pages.

  • Deposit

    Bundtzen, T.K., and Miller, M.L., 1997, Precious metals associated with Late Cretaceous-early Tertiary igneous rocks of southwestern Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Economic Geology Monograph #9, Mineral Deposits of Alaska, p. 242-286.

  • Deposit

    King, H.D., Risoli, D.A., Cooley, E.F., O'Leary, R.M., Speckman, W.A., Speisman, D.L., and Galland, D.W., 1980, Final results and statistical summary of analyses of geochemical samples from the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811F, 134 pages.

Comments on the references

  • Primary Reference = Burleigh, 1992 (BMOFR 85-92)

General comments

Subject category Comment text
Deposit Model Name = Tin Polymetallic (Cox and Singer, 1986; model no. 20b)
Deposit Other Comments = See Won - North (MD021), Gemini, (MD023), and Win (MD060) prospects.

Reporter information

Type Date Name Affiliation Comment
Reporter 03-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting