|Quadrangle map, 1:250,000-scale||PE|
|Quadrangle map, 1:63,360-scale||A-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Shakan molybdenum prospect (also known as the Alaska Treadwell Mining Co), is near the east end of Shakan Strait on northern Kosciusko Island. This well known prospect is on the east side of Shakan Creek at an elevation of about 600 feet, just north of the center of section 23, T. 66 S., R. 77 E.|
The country rocks in the vicinity consist of Cretaceous biotite-quartz hornfels altered from Silurian graywacke turbidite of the Bay of Pillars Formation and a large Cretaceous diorite pluton that intrudes the bedded rocks (Brew and others, 1984).The Shakan molybdenum deposit is at or near the contact between the pluton and the hornfels and probably is genetically related to the emplacement of this pluton. The deposit is a sulfide-bearing fault-breccia zone 1-10 feet thick associated with hornblende diorite pegmatite; the zone contains abundant pyrrhotite, molybdenite, and chalcopyrite, with minor sphalerite and pyrite, in quartz-albite gangue.
|Geologic map unit||(-133.459728113383, 56.1346373777132)|
|Mineral deposit model||Molybdenite associated with pegmatite dike along fault zone.|
|Age of mineralization||Probably Cretaceous based on age of associated pluton.|
|Workings or exploration||The Shakan molybdenum prospect was discovered in 1917 and developed by a 570 foot tunnel and 14 surface cuts during and immediately after World War I (Chapin, 1919). Little or no subsequent exploration work on it beyond cursory examinations by passing geologists, although it was examined at some length by government geologist during World War II (Twenhofel and others, 1946; Smith, 1942, Thorne, 1943).|
|Indication of production||None|
|Reserve estimates||Smith (1942) estimated the resources of the Shakan molybdenum prospect to be 10,000-20,000 tons of rock containing about 1.5% MoS2.|
|MRDS Number||A010342; A010343|
Brew, D.A., Ovenshine, A.T., Karl, S.M., and Hunt, S.J., 1984, Preliminary reconnaissance geologic map of the Petersburg and parts of the Port Alexander and Sumdum 1:250,000 quadrangles, southeastern Alaska: U.S. Geological Survey Open-File Report 84-405, 43 p., 2 sheets, scale 1:250,000.
Chapin, Theodore, 1919, Mining developments in the Ketchikan district: U.S. Geological Survey Bulletin 692-B, p. 85-89.
Cobb, E.H., 1972, Metallic mineral resources map of the Petersburg quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-415, 1 sheet, scale 1:250,000.
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Petersburg quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-870, 53 p.
Coldwell, J.R., 1990, Northwest Canada Mining leads to road proposal: Southeast Alaska Business Journal, December 1990, p. 4.
Gooch, A.E., 1964, Field trip to the Dry Pass and Shakan molybdenum deposits: Alaska Territorial Department of Mines Itinerary Report 117-1, 4 p., 1 sheet, scale 1:63,360.
Grybeck, D.J., Berg, H.C., and Karl, S.M., 1984, Map and description of the mineral deposits in the Petersburg and eastern Port Alexander quadrangles: U.S. Geological Survey Open-File Report 84-837, 86 p., 1 sheet, scale 1:250,000.
Maas, K.M., Bittenbender, P E., and Still, J.C., 1995, Mineral investigations in the Ketchikan mining district, southeastern Alaska: U.S. Bureau of Mines Open-File Report 11-95, 606 p.
Smith, P.S., 1942, Occurrences of molybdenum in Alaska: U.S. Geological Survey Bulletin 926-C, p. 161-210.
Thorne, R.L., 1943, Shakan molybdenum deposit, Kosciusko Island, southeastern Alaska: U.S. Bureau of Mines War Mineral Report 108, 9 p.
|Reporters||H.C. Berg (Fullerton, California) and D.J. Grybeck (USGS)|
|Last report date||11/1/1998|