|Quadrangle map, 1:250,000-scale||TK|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Talkeetna prospect is at an elevation of about 4,400 feet at the head of Prospect Creek, a tributary of the East Fork, Iron Creek. It is in the SE1/4NE1/4 sec. 11, T. 26 N., R. 2 E., Seward Meridian. The location is accurate to within 1/2 mile.|
The Talkeetna prospect consists of: 1) greenstone with replacement bodies of specular hematite and quartz; 2) greenstone breccia with clasts that are partially replaced by pyrite and chalcopyrite in a matrix that contains hematite, chalcopyrite, and quartz; and 3) an east-west shear zone with quartz veinlets that contain pyrite, chalcopyrite, and hematite (Capps, 1919 [B 692]). Amygdules in the greenstone are filled with epidote. Mineralization parallels the shear zone which is up to 30 feet thick and at least several hundred feet long. A conspicuous gossan contains copper carbonates (Capps, 1919 [B 692]). Capps reported samples that contain up to 8 percent copper. Csejtey and Miller (1978) collected float samples that contain small amounts of gold. U.S. Bureau of Mines grab samples contain up to 85,000 parts per million copper and 9.6 parts per million silver; 5-foot chip samples contain up to 25,000 parts per million copper and 5.4 parts per million silver (Fechner, 1986).A number of open cuts and trenches have been excavated through the gossan. As of January 1, 2000, Cominco held a block of approximately 25 state claims covering this and adjacent prospects (Northern Associates Inc., written communication, 2001).
|Geologic map unit||(-149.026021707156, 62.3570062896314)|
|Mineral deposit model||Basaltic Cu (Cox and Singer, 1986; model 23)|
|Mineral deposit model number||23|
|Alteration of deposit||Epidote alteration; oxidation of copper minerals.|
|Workings or exploration||A number of open cuts and trenches have been excavated through the gossan. Capps (1919, p. 203) reported samples with up to 8 percent copper. Examination and sampling by the U.S. Geological Survey and U.S. bureau of Mines (Csejtey and Miller, 1978; Fechner, 1986).|
|Indication of production||None|
Additional commentsMAS/MILS number 20760012.
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.
Capps, S.R., 1919, Mineral resources of the upper Chulitna region: U.S. Geological Survey Bulletin 692-D, p. 207-232.
Capps, S.R., 1924, Geology and mineral resources of the region traversed by the Alaska Railroad: U.S. Geological Survey Bulletin 755-C, p. 73-150.
Cobb, E.H., 1972, Metallic mineral resources map of the Talkeetna Mountains quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-370, 1 sheet, scale 1:250,000.
Cobb, E.H., and Csejtey, Bela, Jr., 1980, Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the Talkeetna Mountains quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-716, 63 p.
Csejtey, Bela, Jr., and Miller, R.J., 1978, Map and table describing metalliferous and selected nonmetalliferous mineral deposits in the Talkeetna Mountains quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-558-B, 22 p., 1 sheet, scale 1:250,000.
Csejtey, Bela, Jr., Nelson, W.H., Jones, D.L., Silberling, N.J., Dean, R.M., Morris, M.S., Lanphere, M.A., Smith, J.G., and Silberman, M.L, 1978, Reconnaissance geologic map and geochronology, Talkeetna Mountains quadrangle, northern part of Anchorage quadrangle, and southwest part of Healy quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-558-A, 60 p., 1 sheet, scale 1:250,000.
Fechner, S.A., 1986, 1984 sample results for Bureau of Mines site-specific mineral investigations within the Yentna Mining District, Alaska: U.S. Bureau of Mines Open-File Report 28-86, 53 p.
MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.
Schmidt, J.M., Werdon, M.B., and Wardlaw, B., 2003, New mapping near Iron Creek, Talkeetna Mountains, indicates presence of Nikolai Greenstone, in Clautice, K.H., and Davis, P.K., eds., 2003, Short Notes on Alaska Geology 2003: Alaska Division of Geological & Geophysical Surveys Professional Report 120, p. 101-108.
Singer, D.A., Csejtey, Bela, Jr., and Miller, R.J., 1978, Map and discussion of the metalliferous and selected non-metalliferous mineral resources of the Talkeetna Mountains quadrangle, Alaska: U.S. Geological Survey Open-file Report 78-558-Q, 33 p., 1 sheet, scale 1:250,000.
Werdon, M.B., Riehle, J.R., Schmidt, J.M., Newberry, R.J., and Pessel, G.H., 2000, Major-oxide, minor-oxide, trace-element, and geochemical data from rocks collected in the Iron Creek area, Talkeetna Mountains B-5 Quadrangle, Alaska in 1999: Alaska Division of Geological & Geophysical Surveys Raw Data File 2000-2, 31 p., 2 sheets, scale 1:63,360.
|Reporters||R.K. Rogers (U. S. Geological Survey contractor)|
|Last report date||10/1/2002|