Bonanza Hills; Bonanza Occurrence, Bristol Bay Mining District, Lake and Peninsula Borough, Alaska, USAi

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

None.
Location: Approximately 230 m SW of the top of peak 3,710 in the Bonanza Hills. Locality 10 of Nelson and others (1985) and locality 157 of Eakins and others (1978). SW1/4SW1/4 sec. 14, T. 8 N., R. 30 W., of the Seward Meridian. Locality accurate within 400 m.
Geology: Narrow zones of en echelon, arsenopyrite and stibnite-bearing quartz veins in shale and sandstone country rock adjacent to a small quartz monzonite plutons and dacite porphyry. The extensive sericitic and silic altered quartz monzonite is one of the numerous small intrusive bodies found in the central part of the Lake Clark 1:250,000 scale quadrangle mapped and identified by Eakins and others (1978), and (Nelson and others (1983, unit TKi5). One of these plutons yielded a potassium-argon biotite age of 71.3 +/- 2.1 m.y. (Eakins and others, 1978). The plutons intrude Lower Cretaceous shale and sandstone, part of the regionally extensive Upper Jurassic and Lower Cretaceous flysch (Nokleberg and others, 1997). Rock chip analyses yield up to 46 ppm Au, 38 ppm Ag, and 1,400 ppm Pb. Gold concentration is estimated to be as much as 42.86 g/t (1.25 oz/ton). The bedrock is poorly exposed and additional sampling is needed to evaluate the prospect.
Workings: Rock chip analyses yield up to 46 ppm Au, 38 ppm Ag, and 1,400 ppm Pb. Gold is estimated to be as much as 42.86 g/t (1.25 oz/ton).
Age: Rocks of the quartz monzonite unit yielded a potassium-argon biotite age of 71.3 +/- 2.1 m.y. (Eakins and others, 1978). Thus, veins are is Late Cretaceous or younger.
Alteration: Extensive sericitic and silicically altered quartz monzonite (Nokleberg and others, 1997).
Production: No production
Reserves: No reserves

Commodities (Major) - Ag, Au; (Minor) - Pb, Sb
Development Status: None
Deposit Model: Polymetallic vein (Cox and Singer, 1986; model 22c)

Other Databases

Link to USGS - Alaska:	LC011

Other Regions, Features and Areas containing this locality

References