Unnamed (in tributary to the Tatina River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Zn
Other commodities Cd; Cu; Mo
Ore minerals chalcopyrite; pyrite
Gangue minerals iron oxides

Geographic location

Quadrangle map, 1:250,000-scale MG
Quadrangle map, 1:63,360-scale B-1
Latitude 62.381
Longitude -153.05
Nearby scientific data Find additional scientific data near this location
Location and accuracy This unnamed occurrence is located in a steep, south-flowing, unnamed tributary of the Tatina River; it is at an elevation of 2,550 feet (777 m) in the SE1/4 sec. 31, T. 27 N., R. 20 W., of the Seward Meridian. The reporter visited the site in 1984; at station no. 84BT120.

Geologic setting

Geologic description

This unnamed occurrence is a mineralized gossan in shale of the Lower Cretaceous Kahiltna Flysch about 500 meters below the contact between the Upper Triassic to Lower Jurassic Tatina River Volcanics and Lower Cretaceous, Kahiltna Flysch (Bundtzen, Harris, and Gilbert, 1997). The gossan strikes east-west across a steep bedrock canyon subparallel to bedding and is about 3 meters thick; the strikelength was not measured. Disseminated chalcopyrite and pyrite were identified in one hand sample, but most mineralization is oxidized. One grab sample of mineralized shale contained 1,200 ppm zinc, 109 ppm copper, 9.3 ppm cadmium, and 7 ppm molybdenum.
Geologic map unit (-153.052237355337, 62.3804119171248)
Mineral deposit model Polymetallic replacement (Cox and Singer, 1986; model 19a).
Mineral deposit model number 19a
Alteration of deposit None.

Production and reserves

Workings or exploration The reporter investigated the site during geologic mapping of the area in 1984 (Bundtzen, Harris, and Gilbert, 1997). One grab sample of mineralized shale contained 1,200 ppm zinc, 109 ppm copper, 9.3 ppm cadmium, and 7 ppm molybdenum.
Indication of production None
Reserve estimates None.

References