|Quadrangle map, 1:250,000-scale||MF|
|Quadrangle map, 1:63,360-scale||C-5|
|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.|
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.|
|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 commentsKimball 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.
Cobb, E.H., 1972, Metallic mineral resources map of the Mount Fairweather quadrangle, AK: U.S. Geological Survey Miscellaneous Field Study Map MF-436, 1 sheet, scale 1:250,000.
Kennedy, G.C., and Walton, M.S., Jr., 1946, Geology and associated mineral deposits of some ultrabasic rock bodies in southeastern Alaska: U.S. Geological Survey Bulletin 947-D, p. 65-84.
Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources, in Brew, D. A., and others, Mineral resources of the Glacier Bay National Monument wilderness study area, Alaska: U.S. Geological Survey Open-File Report 78-494, p. C1-C375.
|Reporters||C.C. Hawley (Hawley Resource Group)|
|Last report date||12/15/1998|