|Quadrangle map, 1:250,000-scale||SR|
|Quadrangle map, 1:63,360-scale||C-7|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is at an elevation of 4,250 feet on the divide betwee the two forks of Groundhog Creek. It is located in the NW1/4 section 4, T. 6 N., R. 1 E., of the Seward Meridian. This location is accurate to within a quarter of a mile. This is location 35 of Cobb and Richter (1972), location 24 of MacKevett and Holloway (1977), location 36 of Cobb and Tysdal (1980), and location S-268 of Jansons and others (1984).|
The deposit consists of auriferous, sulfide-bearing, quartz-calcite veins that fill fractures in a shear zone in slate of the Valdez Group of Late Cretaceous age. The zone is 5 to 6 feet wide and extends S80E between two pale-greenish porphyritic dikes (Johnson, 1912). Much of the quartz is coarsely crystalline and is accompanied by a small amount of calcite, along with arsenopyrite, galena, sphalerite, and gold. The vein material is weathered and decomposed and has been traced about a hundred feet. The vein dips steeply south, nearly vertically. A narrow streak of fault gouge lies along the hanging wall at the shear zone. The gold is free-milling or in the arsenopyrite and galena. Specimens from the outcrop contain visible free gold (Johnson, 1912).The workings on this prospect consist of trenches and a 90-foot adit with 23 feet of winzes, a 12-foot crosscut, and a 15-foot shaft (Johnson, 1912). The adit collapsed in 1911 (Martin and others, 1915).
|Geologic map unit||(-149.297323162649, 60.6441187688884)|
|Mineral deposit model||Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)|
|Mineral deposit model number||36a|
|Age of mineralization||Cretaceous or younger; the veins cut rocks of the Valdez Group of Late Cretaceous age.|
|Workings or exploration||
The workings on this prospect consist of trenches and a 90-foot adit with 23 feet of winzes, a 12-foot crosscut, and a 15-foot shaft (Johnson, 1912). The adit collapsed in 1911 (Martin and others, 1915).The U.S. Bureau of Mines examined the prospect and collected samples in 1981. Two chip samples assayed a trace and 0.02 ounces of gold per ton, and a trace and 0.23 ounces of silver per ton. Two selected grab samples assayed 0.79 and 0.99 ounce of gold per ton, and 0.08 and 0.46 ounce of silver per ton. A grab sample of dump material contained a trace of gold and 0.02 ounce of silver per ton (Jansons and others, 1984).
|Indication of production||None|
Cobb, E.H., and Richter, D.H., 1972, Metallic mineral resources map of the Seward quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-466, 2 sheets, scale 1:250,000.
Cobb, E.H., and Tysdal, R.G., 1980, Summaries of data on and list of references to metallic and selected nonmetallic mineral deposits in the Blying Sound and Seward quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-621, 276 p.
Hoekzema, R.P., and Sherman, G.E., 1983, Mineral investigations in the Chugach National Forest, Alaska (Peninsula study area): U.S. Bureau of Mines in-house report; held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 524 p.
Jansons, Uldis, Hoekzema, R.B., Kurtak, J.M., and Fechner, S.A., 1984, Mineral occurrences in the Chugach National Forest, southcentral Alaska: U.S. Bureau of Mines Mineral Land Assessment 5-84, 218 p., 2 sheets, scale 1:250,000.
Johnson, B.L., 1912, Mineral resources of Alaska, report on progress of investigations in 1911--Gold deposits of the Seward-Sunrise region, Kenai Peninsula: U.S. Geological Survey Bulletin 520-E, p. 131-173.
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.
Martin, G.C., Johnson, B.L., and Grant, U.S., 1915, Geology and mineral resources of Kenai Peninsula, Alaska: U.S. Geological Survey Bulletin 587, 243 p.
Nelson, S.W., Dumoulin, J. A., and Miller, M.L., 1985, Geologic map of the Chugach National Forest, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1645-B, 16 p., 1 sheet, scale 1:250,000.
Tuck, Ralph, 1933, The Moose Pass-Hope district, Kenai Peninsula, Alaska: U.S. Geological Survey Bulletin 849-I, p. 469-530.
|Reporters||Jeff A. Huber (Anchorage)|
|Last report date||1/25/2000|