Tin Creek-North Occurrence, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Tin Creek-North Occurrence	Occurrence
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

See MG042, Tin Creek-Midway (MG043) and Tin Creek-South (MG046) prospects.
Location: The Tin Creek-North occurrence is located near a 4,955 foot (1,510 m) summit about 6 kilometers east of Sheep Creek. The reporter visited the site in 1980.
Geology:
The Tin Creek Zn-Pb skarn is zoned from predominantly a garnet skarn with abundant chalcopyrite and stockwork quartz veining in the northern part (MW zone) to a pyroxene skarn dominated by sphalerite in the southern part (TC1 zone) (Lu et al., 1992).

The Tin Creek-North occurrence consists of thin, 5 to 20 centimeter thick mineral veins containing johansenite, garnet, sphalerite (marmatite), and chalcopyrite in argillaceous limestone of the mid-Silurian Terra Cotta Mountains Sandstone a unit of the Dillinger subterrane (Bundtzen, Harris, and Gilbert, 1997). The mineralization is hosted within a thermally altered zone where prograde garnet-johansenite veins are cut by epidote replacement bodies that are accompanied by sulfide minerals. The sulfide skarns are near a 29 Ma granidiorite dike which is part of a larger, 5 kilometer wide, N70W-trending dike swarm which intrudes the Dillinger subterrane. One grab sample contained 2.25 percent copper, 1.21 percent lead, 0.11 percent zinc, 0.13 percent cadmium, and 319.8 grams/tonne silver (Bundtzen, Kline, and Clough, 1982; Szumigala, 1987).
Workings: The Tin Creek-North occurrence was first described in Bundtzen, Kline, and Clough (1982). One grab sample contained 2.25 percent copper, 1.21 percent lead, 0.11 percent zinc, 0.13 percent cadmium, and 319.8 grams/tonne silver (Bundtzen, Kline, and Clough, 1982; Szumigala, 1987).
Age: Inferred to be 29 Ma, based on age date from nearby granodiorite dike (Solie and others, 1991).
Alteration: Epidotization.
Reserves: None.

Commodities (Major) - Ag, Cu, Pb, Zn; (Minor) - Cd
Development Status: No
Deposit Model: Copper-iron skarn (Cox and Singer, 1986; model 18b).

Other Databases

Link to USGS - Alaska:	MG041

Other Regions, Features and Areas containing this locality

References