Unnamed (near Falling Glacier)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Cr; Ni; Sn; Zn
Ore minerals chalcopyrite; pyrite
Gangue minerals feldspar; quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-5
Latitude 60.4923
Longitude -148.565
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is located in the SW1/4 section 27, T. 5 N., R. 5 E., of the Seward Meridian. It is along the north side of Falling Glacier on the east shore of Kings Bay and at an elevation of 660 feet. This is location 171 of Tysdal (1978 [MF-880-A]) and location S-92 of Jansons and others (1984). This location is accurate to within 300 feet.

Geologic setting

Geologic description

The occurrence consists of an iron-stained, laminated, siliceous mudstone that is locally cut by quart-feldspar veinlets near a granite contact. Traces of chalcopyrite and as much as 2 percent pyrite occur as disseminations and fracture fillings in the mudstone (Kurtak and Jeske, 1986). The mudstone is Orca Group of early Tertiary age (Nelson and others, 1985). The granite belongs to the informally named Nellie Juan granite, which has been dated as 35.5 +/-0.9 my old (Lanphere, 1966).
One random chip sample across siliceous mudstone and quartz-feldspar veinlets contained 96 ppm copper (Kurtak and Jeske, 1986). A sample collected by Tysdal (1978 [MF-880-A]) contained 300 ppm chromite, 85 ppm copper, 100 ppm nickel, 50 ppm tin, and 90 ppm zinc.
Geologic map unit (-148.567070784896, 60.4916667819148)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Mineral deposit model number 36a
Age of mineralization Tertiary or younger; the mineralization is in rocks of the Orca Group of Tertiary age.
Alteration of deposit The mudstone is iron-stained.

Production and reserves

Workings or exploration One random chip sample across siliceous mudstone and quartz-feldspar veinlets contained 96 ppm copper (Kurtak and Jeske, 1986). A sample collected by Tysdal (1978 [MF-880-A]) contained 300 ppm chromite, 85 ppm copper, 100 ppm nickel, 50 ppm tin, and 90 ppm zinc. No workings or improvements are reported.
Indication of production None

References