Unnamed (west mouth of Rendu Inlet)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Co; Ni
Ore minerals chalcopyrite; pyrite; pyrrhotite

Geographic location

Quadrangle map, 1:250,000-scale MF
Quadrangle map, 1:63,360-scale D-2
Latitude 58.913
Longitude -136.628
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is near sea level at the west mouth of Rendu Inlet 0.45 miles northeast of VABM Rendu. It is about 1.5 miles north of the point between Rendu Inlet and Glacier Bay. The location is probably accurate within 0.1 mile. The location is number 38 of MacKevett and others (1971), number 33 0f Cobb (1972), and number 43 of Kimball and others (1978).

Geologic setting

Geologic description

Iron-stained pyritic zones up to 20 feet long and 1 foot thick occur in bleached marble of the Paleozoic marble and hornfels unit of Brew and others (1978). The unit is probably correlative with post-Silurian pre-Triassic limestone of Seitz (1959). The bedded rocks are intruded by granitic rocks of Cretaceous age. A pyritic zone containing minor chalcopyrite and possibly pyrrhotite was sampled by MacKevett and others (1971, table 9). A selected sample from a thin pyrite-rich lens contained 1500 ppm copper, 700 ppm cobalt, and 1000 ppm nickel, suggesting the prescence of nickeliferous pyrrhotite as an additional phase.
Geologic map unit (-136.629865501475, 58.9126076403615)
Age of mineralization Cretaceous or younger.
Alteration of deposit Bleaching of marble near sulfidized zones.

Production and reserves

Workings or exploration Surface exposures only, 2 samples collected (MacKevett and others, 1971).
Indication of production None

Additional comments

Paleozoic marble invaded by granitic plutons of Cretaceous age. The area is in Glacier Bay National Park and Preserve.