Bonanza Hills; Main Saddle Prospect, Bristol Bay Mining District, Lake and Peninsula Borough, Alaska, USAi

Regional Level Types
Bonanza Hills; Main Saddle Prospect	Prospect
Bristol Bay Mining District	Mining District
Lake and Peninsula Borough	Borough
Alaska	State
USA	Country

Location: The Bonanza Hills prospect extends about 1.5 km along a ridge, between peak 3,860 and peak 3,966, in the Bonanza Hills. It is approximately 3.5 km east-southeast of Little (Upper) Bonanza Creek in the SW1/4SW1/4 sec. 6, T. 7 N., R. 30 W., of the Seward Meridian. The location is accurate.
Geology: A quartz-sulfide vein system containing tetrahedrite, arsenopyrite, galena, and chalcopyrite cuts sedimentary rocks and dacite hornfels (Eakins and others, 1978). The mineralization consists of a 3-meter-wide zone of quartz sulfide 'splatter' veinlets that extends at least 150 meters along strike to a depth of 50 meters. Channel samples contain an average of 103 grams of silver per tonne and 0.5 percent combined Cu and Pb. Samples contain up to 2.24 parts per million (ppm) gold. The contact-metamorphosed dacite flows and sedimentary rocks are part of a Jurassic to Cretaceous unit (KJs) that consists of interbedded lithic graywacke, silty sandstone, black shale, and local conglomerate (Nelson and others, 1983). Irregular quartz segregations and veinlets are locally present. Scattered stocks and locally abundant dikes of intermediate to felsic composition intrude these sedimentary rocks. Contact aureoles of hornfels ring some of the larger igneous bodies which include rhyolite dikes and a Late Cretaceous, two-mica, hypabyssal, granite pluton (Nokleberg and others, 1997). Liberty Star Uranium and Metals Corporation (2007) has 54 State of Alaska claims covering about 13.5 square miles around this prospect. Twenty samples were collected in their preliminary work; 5 contained 0.001 to 0.006 ounce of gold per ton, 2 contained 0.02 ounce of gold per ton, 1 contained 0.267 ounce of gold per ton, one contained 0.403 ounce of gold per ton, and one contained 3.11 ounces of gold per ton.
Workings: In 2008 within a large block of claims held by Liberty Star Uranium and Metals Corporation who did preliminary sampling.
Age: Cretaceous or younger.
Alteration: Unknown.
Production: No production.
Reserves: Nokleberg and others (1987; 1997) estimate that the deposit contains 45,000 tonnes of material with a grade of 81 grams of silver per tonne, 0.15 grams of gold per tonne, 0.15 percent copper, and 0.067 percent lead.

Commodities (Major) - Ag, Cu, Pb; (Minor) - Au
Development Status: None
Deposit Model: Gold vein system or disseminated gold deposit associated with a composite intrus

Other Databases

Link to USGS - Alaska:	LC016

Other Regions, Features and Areas containing this locality

References