Shakan (ARDF #PE048) Mo

Shakan

Prospect, Probably inactive

Alternative names

Alaska Treadwell Mining Co.

Commodities and mineralogy

Main commodities	Mo
Other commodities	Cu; Zn
Ore minerals	chalcopyrite; molybdenite; pyrite; pyrrhotite; sphalerite
Gangue minerals	albite; quartz

Geographic location

Quadrangle map, 1:250,000-scale	PE
Quadrangle map, 1:63,360-scale	A-5
Latitude	56.135
Longitude	-133.458
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.

Geologic setting

Geologic description 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.

Production and reserves

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.
Production notes	None

References

MRDS Number	A010342; A010343
References 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. Hess, F.L., 1924, Molybdenum deposits, a short review: U.S. Geological Survey Bulletin 761, 35 p. 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. Twenhofel, W.S., Robinson, G.D., and Gault, H.R., 1946, Molybdenite investigations in southeastern Alaska: U.S. Geological Survey Bulletin 947-B, p. 7-38.
Reporters	H.C. Berg (Fullerton, California) and D.J. Grybeck (USGS)
Last report date	11/1/1998