Unnamed (west head of Hugh Miller Glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag; Au; Fe; Mn
Ore minerals arsenopyrite; chalcopyrite; pyrite
Gangue minerals epidote; garnet

Geographic location

Quadrangle map, 1:250,000-scale MF
Quadrangle map, 1:63,360-scale D-3
Latitude 58.785
Longitude -136.765
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is on a ridge west of the head of Hugh Miller Glacier at an elevation of about 4100 feet. It is about 0.75 mile east of Reid Glacier at a point about 4 miles above the terminous of the glacier at Reid Inlet. The location is accurate within 0.1 mile. The site of the occurrence is location number 50 of Kimball and others (1978).

Geologic setting

Geologic description

The occurrence is in the middle Geickie province of Brew and others (1978). Rocks are mainly hornfels, phyllite, semischist and marble of Paleozoic age which are cut and locally contact metamorphosed by granitic bodies of Cretaceous age. At the mineral locality, pyrite-rich epidote-garnet skarn layers are as much as 3 feet thick. Locally, chalcopyrite and arsenopyrite are present in the skarn. Massive pyrite skarn contains as much as 1100 ppm copper, 1.5 ppm silver, 0.15 ppm gold, 5000 ppm manganese and greater than 20 percent iron (Kimball and others, 1978, p. C248, location 50).
Geologic map unit (-136.766860007316, 58.78460589459)
Mineral deposit model Iron-copper skarn somewhat similar to Cu skarn and Fe skarn (Cox and Singer, 1986; model 18b and 18d).
Mineral deposit model number 18b and 18d
Age of mineralization Cretaceous.
Alteration of deposit Marble has been converted to pyritic garnet-epidote skarn.

Production and reserves

Workings or exploration There are no mine workings; exposures limited to surface outcrops. Chip samples of pyrite-rich sulfide layers showed > 20 percent iron, from 730 to 1100 ppm copper and trace amounts of silver and gold (Kimball and others, 1978).
Indication of production None

Additional comments

Cretaceous-aged mineralization of a terrane of Paleozoic age. The area is in Glacier Bay National Park and Preserve.

References