|Quadrangle map, 1:250,000-scale||LC|
|Quadrangle map, 1:63,360-scale||A-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||About 5.6 km south of the western end of Kontrashibuna Lake, near the headwaters of Takoka Creek on peak 4,367. This is locality 10 of MacKevett and Holloway (1977). Sec. 33, T. 1 N., R. 28 W., of the Seward Meridian. Location accurate within 1.6 km.|
Geologic descriptionOccurrence identified by 58 lode iron claims (U.S. Bureau of Mines, 1973). MacKevett and Holloway (1977) reported that the occurrence may be in mineralized zones of contact-metamorphosed Upper Triassic limestone and dolomite that has been intruded by Tertiary, medium- to fine-grained hornblende-biotite quartz monzodiorite (Nelson and others, 1983; unit Ti2). The pluton yields concordant potassium-argon ages for hornblende and biotite of about 61 m.y. (Reed and Lanphere, 1972; 1973). Other nearby rocks include Tertiary volcanic rocks, which include rhyolitic breccia, ash-flow tuff, flows, felsic intrusive rocks, and subordinate mafic to intermediate flows (Nelson and others, 1983; unit Tv). Potassium-argon ages for Unit Tv range from 56.2 to 62.7 m.y. (Eakins and others, 1978).
|Geologic map unit||(-154.152195158129, 60.1293368429029)|
|Mineral deposit model||Fe skarn? or Cu skarn? (Cox and Singer, 1986; model 18d? or 18b?)|
|Mineral deposit model number||18d? or 18b?|
|Age of mineralization||Mineralization is Tertiary or younger. The quartz monzodiorite which is probably the source of the skarn yields concordant potassium-argon ages for hornblende and biotite of about 61 m.y. (Reed and Lanphere, 1972; 1973). Potassium-argon ages for the volcanic rocks range from 56.2 to 62.7 m.y. (Eakins and others, 1978).|
|Alteration of deposit||Unknown|
|Workings or exploration||Unknown|
|Indication of production||None|
|Reserve estimates||No reserves|
|Production notes||No production|
Additional commentsSite is in Lake Clark National Park and Preserve.
Eakins, G.R., Gilbert W.G., and Buntzen, T.K., 1978, Preliminary bedrock geology and mineral resource potential of west-central Lake Clark quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File Report 118, 15 p., 2 plates, scale 1:25,000.
MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000.
Nelson, W.H., Carlson, C., and Case, J.E., 1983, Geologic map of the Lake Clark quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1114-A, 1 sheet, scale 1:250,000.
Reed, B.L., and Lanphere, M.A., 1972, Generalized geologic map of the Alaska-Aleutian range batholith showing potassium-argon ages of the plutonic rocks: U.S. Geological Survey Miscellaneous Field Studies Map MF-372, 2 sheets, scale 1:1,000,000.
Reed, B.L., and Lanphere, M.A., 1973, Alaska-Aleutian Range batholith: Geochronology, chemistry, and relation to circum-Pacific plutonism: Geological Society of America Bulletin, v. 84, no. 8, p. 2583-2609.
U.S. Bureau of Mines, 1973, Alaska 1:250,000-scale quadrangle map overlays showing mineral deposit locations, principal minerals, and number and type of claims: U.S. Bureau of Mines Open-File Report 20-73, 95 overlays (updated in 1986, 1987).
|Reporters||D.P. Bickerstaff (USGS)|
|Last report date||6/15/1998|