|Quadrangle map, 1:250,000-scale||TK|
|Quadrangle map, 1:63,360-scale||D-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Three mineralized sites are on or near Treasure Creek, a small informally named, east tributary of Portage Creek. The mouth of Treasure Creek is 4 miles upstream from the mouth of Portage Creek on the Susitna River The sites are within a mile of each other in an area centered in the NE1/4SE1/4 sec. 8, T. 32 N., R. 1 E., Seward Meridian. This is locality 9 of Csejtey and Miller, (1978).|
The three mineralized sites of the prospect have disseminated arsenopyrite, chalcopyrite, molybdenite, and sphalerite, quartz, fluorite, and epidote in a silicified and sheared Tertiary granite stock, and in argillite and metagraywacke intruded by the granite (Richter, 1963). There is local intense argillic alteration and limonite staining that extends irregularly up to 300 feet into the granite from a fault. The argillite and metagraywacke are part of an extensive Lower Cretaceous flysch unit. The stock is part of the lower Tertiary McKinley plutonic sequence. Samples of an arsenopyrite-rich boulder found on the surface contain 0.18 ounce of gold per ton, 2-3 percent zinc, 0.1-0.5 percent copper, and 0.1-0.5 percent molybdenum (Richter, 1963). Rock samples from one of the sites contain contain up to 1.0 percent molybdenum, 2.65 percent zinc, and 1.7 ounces of silver per ton (Kurtak and others, 1992).This prospect was explored by minor surface workings and shallow drilling. A caved adit is 500 feet south of the creek, near the east boundary of section 8 at an elevation of about 1,400 feet. Silver Dome Mining Company staked the Molly 1 to 18 claims, the Caribou 1 to 59 claims, and the Cheechako Moose 1 to 21 claims.
|Geologic map unit||(-149.296562433004, 62.877219429238)|
|Mineral deposit model||Porphyry Cu-Mo (Cox and Singer, 1986; model 21a)|
|Mineral deposit model number||21a|
|Age of mineralization||In Early Tertiary rocks.|
|Alteration of deposit||Silicification, argillic and epidote alteration, with iron staining.|
|Workings or exploration||This prospect was explored by minor surface workings and shallow drilling. A caved adit is 500 feet south of the creek, near the east boundary of section 8 at an elevation of about 1,400 feet. Rock sampling by the U.S. Geological Survey and U.S. Bureau of Mines (Richter, 1963; Kurtak and others, 1992). Silver Dome Mining Company staked the Molly 1 to 18 claims, the Caribou 1 to 59 claims, and the Cheechako Moose 1 to 21 claims.|
|Indication of production||None|
Additional commentsMAS/MILS number 20760005.
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.
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.
Karlson, R.C., Curtin, G.C., Cooley, E.F., and Garmezy, Larry, 1977, Geochemical maps of selected elements and results of spectrographic analyses for heavy-mineral concentrates from the western half of the Talkeetna Mountains quadrangle, Alaska: U.S. Geological Survey Open-File Report 77-530, 32 p., 5 sheets, scale 1:250,000.
Kurtak, J.M., Southworth, D.D., Balen, M.D., and Clautice, K.H., 1991, Mineral investigations in the Valdez Creek Mining District, south-central Alaska: U.S. Bureau of Mines Open-File Report 1-92, 658 p., 2 sheets, scale 1:250,000.
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.
Nokleberg, W.J., Bundtzen, T.K., Berg, H.C., Brew, D.A., Grybeck, D.J., Robinson, M.S., Smith, T.E., and Yeend, W., 1987, Significant metalliferous lode deposits and placer districts of Alaska: U.S. Geological Survey Bulletin 1786, 104 p., 2 plates, scale 1:5,000,000.
Richter, D.H., 1963, Geology of the Portage Creek-Susitna River area, Alaska: Alaska Division of Mines and Minerals Geologic Report 3, 2 plates, scale 1:24,000.
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.
|Reporters||R.K. Rogers (U. S. Geological Survey contractor)|
|Last report date||9/26/2002|