Unnamed (east head of Whitewing Valley)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au
Other commodities As; Bi; Cu; Sb; W
Ore minerals goethite after sulfide; scheelite
Gangue minerals barite; quartz; tourmaline

Geographic location

Quadrangle map, 1:250,000-scale SM
Quadrangle map, 1:63,360-scale C-7
Latitude 61.73366
Longitude -158.46808
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 2,100 feet on a steep, southwest-facing knob east of junction of the two headwater tributaries in the cirque at the head of the Whitewing Valley. The occurrence is about 0.3 mile southeast of the center of section 14, T. 19 N., R. 51 W., of the Seward Meridian and 0.8 mile southeast of peak 3310. The location is accurate.

Geologic setting

Geologic description

This occurrence consists of a sulfide-bearing quartz greisen in and adjacent to a felsic dike that intrudes syenite of the Cretaceous Horn Mountains pluton. Fine-grained disseminated sulfides occur both in the dike and in a quartz greisen breccia zone in the syenite; the greisen also contains barite and tourmaline. The sulfides are oxidized to goethite. One grab sample taken from the mineralized zone contained 113 parts per billion (ppb) gold, 1,400 ppb silver, 171 parts per million (ppm) copper, 171 ppm arsenic, 82 ppm antimony, 2,300 ppm barium, and 2.0 ppm bismuth (Bundtzen and others, 1998).
The occurrence is in an area of anomalous stream sediment and panned concentrate samples (Gray and others, 1994; Theodorakos and others, 1992). The stream sediment samples contained up to 700 ppb gold, 680 ppb silver, 120 ppm copper, 370 ppm arsenic, 35 ppm antimony, and other elevated metal values. Panned concentrates contained up to 30.0 ppm gold, 15.0 ppm silver, 2,000 ppm lead, 300 ppm antimony, 1,000 ppm bismuth, and 700 ppm tungsten; several samples contained microscopically visible gold, scheelite, and barite.
Geologic map unit (-158.470457235782, 61.73295472651)
Mineral deposit model Silver-polymetallic veins or tin veins (Cox and Singer, 1986; models 20b or 15b).
Mineral deposit model number 20b or 15b
Age of mineralization May be related to the Horn Mountain pluton which has been dated at 68-69 Ma (Bundtzen and others, 1998).
Alteration of deposit Development of quartz-tourmaline greisen; oxidation of sulfides.

Production and reserves

Workings or exploration Surface sampling was conducted by the Alaska Division of Geological and Geophysical Surveys in 1990 (Bundtzen and others, 1998).
Indication of production None

References