Unnamed (in the northern Chilkat Range)

Occurrence, Probably inactive

Commodities and mineralogy

Main commodities Ag; Cu
Other commodities Co
Ore minerals chalcopyrite; pyrite; pyrrhotite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SK
Quadrangle map, 1:63,360-scale A-2
Latitude 59.15
Longitude -135.72
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 5,000 feet about 3.7 miles, S87W from triangulation station 'Bow' on the west side of Chilkat Inlet. It is in the SW1/4, section 25, T. 31 S., R. 58 E. of the Copper River Meridian and is in a narrow septum of rock between two unnamed ice fields. The location corresponds to location 68 of Gilbert (1988).

Geologic setting

Geologic description

Gilbert (1988) collected four rock samples described as, 'skarn with pyrrhotite (60%) and chalcopyrite', 'gossan with pyrrhotite', 'black schist with pyrrhotite (20%)', and 'quartz with pyrite in shear'. The samples contain up to 4.6 ppm silver, 5,950 ppm copper, and 95 ppm cobalt. The host rocks are mafic Paleozoic metavolcanics and metasediments that include argillaceous marble. Cretaceous medium-grained hornblende diorite and foliated granodiorite are nearby (Gilbert, 1988). The mineralization is probably the same age as the nearby Cretaceous intrusive rocks.
Geologic map unit (-135.721850605768, 59.1496575925271)
Mineral deposit model Copper skarn? (Cox and Singer, 1986: model 18b?)
Mineral deposit model number 18b?
Age of mineralization The age is inferred to be Cretaceous based upon the Cretaceous age of nearby intrusive rocks (Gilbert, 1988).
Alteration of deposit Skarn.

Production and reserves

Indication of production None

References