|Quadrangle map, 1:250,000-scale||MF|
|Quadrangle map, 1:63,360-scale||B-1|
|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).|
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.|
|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 commentsThe occurrence is in Glacier Bay National Park and Preserve.
Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p., 7 sheets.
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.
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||4/14/1999|