Unnamed (near the mouth of Crillon Inlet to Lituya Bay)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; Ni
Other commodities Ag; Au; Co
Ore minerals chalcopyrite; goethite; nickeliferous pyrrhotite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale MF
Quadrangle map, 1:63,360-scale C-5
Latitude 58.657
Longitude -137.484
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is approximately 0.2 mile south of triangulation station Berg at the mouth of Crillon Inlet to Lituya Bay at an inferred elevation of about 800 feet. A float sample was collected near 58.658 and 137.484 at the base of the cliff, and this is the location shown as number 1 of Kimball and others (1978), number 84 of MacKevett and others (1971) and location 1 of Cobb (1972). Kennedy and Walton (1946) report a stained gabbroic rock on the southwest shore of the southeast arm of Lituya Bay, presumably the same--and original location--of the occurrence.

Geologic setting

Geologic description

Disseminated sulfide minerals (chalcopyrite and pyrrhotite) occur in gabbro about 0.6 mile southwest of the Fairweather fault within the eastern part of the Lituya terrane defined by Brew and others (1978). The eastern part of the Lituya terrane is similar to the adjacent Fairweather terrane in abundance of intrusive rocks and presence of schistose metasedimentary and metavolcanic rocks.
Mineralized (iron-stained) float was at the base of a cliff by the U.S. Bureau of Mines (Kimball and others, 1978, p. C93). Earlier Kennedy and Walton (1946, p. 71) had reported a gabbro dike, that contained about 1 percent chalcopyrite, also, pyrrhotite, cut granitic rock near the same location. Kimball and others (1978, p. C93) reported that the iron-stained float in scree contained as much as 1600 ppm copper, 2000 ppm nickel, 300 ppm cobalt and traces of gold and silver. Visible minerals in the scree float were quartz, chlorite, epidote, hornblende, pyrite and secondary goethite. The U.S. Bureau of Mines investigators observed a conspicuous iron-stained zone on the cliff that they inferred could be the dike reported by Kennedy and Walton, but they did not have time to investigate the possible source.
Geologic map unit (-137.485936360753, 58.6566367810794)
Mineral deposit model Disseminated copper and nickel? sulfide minerals in an altered mafic dike.
Age of mineralization Tertiary.
Alteration of deposit Limonitic staining.

Production and reserves

Workings or exploration Surface exposure, cliff and talus. A float sample of iron-stained altered gabbro(?) from the talus contained 2000 ppm nickel, 1600 ppm copper, 300 ppm cobalt, 1 ppm silver, and 0.15 ppm gold. Kennedy and Walton (1946) reported a gabbro dike from the same area that contained disseminated chalcopyrite.
Indication of production None

Additional comments

Kimball and others (1978) did not recover the mineralized dike reported earlier by Kennedy and Walton (1946), but they did note iron-stained on the cliff above the mineralized scree at the base of the cliff. The Bureau of Mines party did not have time to examine the stained occurrence. The site is in Glacier Bay National Park and Preserve.

References