Unnamed (east of Dundas Bay)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu; Mo
Other commodities Ag
Ore minerals chalcopyrite; malachite; molybdenite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale MF
Quadrangle map, 1:63,360-scale B-1
Latitude 58.355
Longitude -136.28
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 100 feet on the east side of Dundas Bay about 2.5 miles north of the mouth of the Bay. It is about 0.5 mile northeast of triangulation station Deed and is accurately located within about 0.25 mile. The location is approximately the same as number 58 of Cobb (1972), number 32 of MacKevett and others (1971), and number 68 of Kimball and others (1978).

Geologic setting

Geologic description

A foliated quartz diorite of Cretaceous age forms a stock-like pluton on the east side of the mouth of Dundas Bay. It is in contact to the north with metamorphosed sedimentary rocks of Devonian and Silurian age (Brew and others, 1978). MacKevett and others (1971) found malachite-stained quartz stringers, containing chalcopyrite and molybdenite, within quartz veins in cataclastic quartz diorite. The veins are of Late Cretaceous or younger age.
A sample collected to represent quartz-vein-bearing sheared rock contained 1000 ppm copper and 300 ppm molybdenum. Samples collected by the U.S. Bureau of Mines from the same or nearby sites contained as much as 1900 ppm copper, 10 ppm molybdenum, and 1 ppm silver.
Geologic map unit (-136.281838135844, 58.3546422944152)
Mineral deposit model Low-sulfide quartz-copper-bearing vein.
Age of mineralization Probably Cretaceous or younger.
Alteration of deposit Local oxidation of copper minerals.

Production and reserves

Workings or exploration There are no workings. A representative sample of copper-stained sheared and quartz-veined quartz diorite collected by MacKevett and others (1971, table 9 location 32) contained 1000 ppm copper and 300 ppm molybdenum. Chip samples collected by Bureau of Mines (Kimball and others, 1978, p. C270) contained as much as 1900 ppm copper, 10 ppm molybdenum and 1 ppm silver.
Indication of production None

Additional comments

The occurrence is in Glacier Bay National Park and Preserve.