|Quadrangle map, 1:250,000-scale||IL|
|Quadrangle map, 1:63,360-scale||A-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is at an elevation of about 1,600 feet, east of the head of Lake Fork and 1.35 miles west of hill 3169. The prospect is in the NW1/4 sec.10, T. 11 S., R. 31 W., Seward Meridian. The site corresponds to locality 17 of Detterman and Cobb (1972) and locality 17 of Reed (1967), and is accurate within about 0.5 mile.|
The area of this prospect is underlain mainly by Jurassic, biotite-hornblende quartz diorite (Detterman and Reed, 1980). At the prospect, the quartz diorite intrudes hornblende gabbro (Reed, 1967).
The prospect is a 100- to 150-foot-wide breccia zone in quartz diorite. The breccia is cut by a 0.5- to 2-foot-wide, malachite-stained fault zone and by many smaller, sulfide-rich, quartz(?) veins. The sulfides almost certainly include chalcopyrite and pyrite. Four of five grab samples of mineralized rock collected by Reed (1967) contained more than 0.5 percent copper. One grab sample assayed 11.9 parts per million (ppm) gold, 20 ppm silver, and more than 5,000 ppm copper. Selected sulfide-rich specimens from the mineralized fault zone yielded assays of more than 0.5 ounce of gold per ton (Reed, 1967; Cobb, 1976).The prospect was restaked in 1964, possibly for iron present as magnetite(?). A short, partly caved, adit found by Reed (1967) dates from an earlier period of exploration.
|Geologic map unit||(-154.486830263972, 59.241514258151)|
|Mineral deposit model||Polymetallic vein? (Cox and Singer, 1986; model 22c).|
|Mineral deposit model number||22c?|
|Age of mineralization||Jurassic or younger.|
|Alteration of deposit||Oxidation of copper.|
|Workings or exploration||The prospect was explored by a short adit that was partly caved when visited by Reed (1967). The prospect area was restaked in 1964 during a flurry of exploration for iron on the Alaska Peninsula.|
|Indication of production||None|
Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-485, 101 p.
Cobb, E.H., and Reed, B.L., 1981, Summaries of data on and lists of references to metallic and selected nonmetallic mineral occurrences in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska; Supplement to Open-File Report 76-485; Part A, Summaries to January 1, 1981: U.S. Geological Survey Open-File Report 81-1343-A, 25 p.
Cobb, E.H., and Reed, B.L., 1981, Summaries of data on and lists of references to metallic and selected nonmetallic mineral occurrences in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska; Supplement to Open-File Report 76-485; Part B, Lists of references to Januray 1, 1981: U.S. Geological Survey Open-File Report 81-1343-B, 20 p.
Detterman, R.L., and Cobb, E.H., 1972, Metallic mineral resources map of the Iliamna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-364, 1 sheet, scale 1:250,000.
Detterman, R.L., and Reed, B.L., 1980, Stratigraphy, structure, and economic geology of the Iliamna quadrangle, Alaska: U.S. Geological Survey Bulletin 1368-B, 86 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.
|Reporters||C.C. Hawley, Hawley Resource Group, Anchorage, Alaska|
|Last report date||6/9/2003|