Won - South; Prospect Pit; Dog Day; Gash; Tin Ridge Prospect, Innoko Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Won - South; Prospect Pit; Dog Day; Gash; Tin Ridge Prospect	Prospect
Innoko Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

See Won - North (MD021), Gemini, (MD023), and Win (MD060) prospects.
Location: 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.
Geology: 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.
Workings: 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.
Age: Late Cretaceous-early Tertiary (inferred) based on age range of plutons in Kuskokwim Mineral belt (Bundtzen and Miller, 1997).
Alteration: Sericite-quartz in intermediate dikes.
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.

Commodities (Major) - Ag, Sn; (Minor) - As, Cu, Pb, Sb, W, Zn
Development Status: No
Deposit Model: Tin Polymetallic (Cox and Singer, 1986; model no. 20b)

Other Databases

Link to USGS - Alaska:	MD024

Other Regions, Features and Areas containing this locality

References