|Quadrangle map, 1:250,000-scale||SR|
|Quadrangle map, 1:63,360-scale||D-7|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Bonanza prospect in the Downing mine area (see additional comments). The prospect is at an elevation of about 2,100 feet on the north bank of Bonanza Creek. It is in the S1/2 section 31, T. 9 N., R. 1 W., of the Seward Meridian. The Bonanza prospect is located about half way between the Francisco (SR017) and Whistler (SR020) properties. This is location 9 of Cobb and Richter (1972), location 8 of MacKevett and Holloway (1977), locations 17, 19, and 20 of Cobb and Tysdal (1980), location 19 of Tysdal (1978 [MF-880-A]), and location S-294 of Jansons and others (1984). The location is accurate to within half a mile.|
Geologic descriptionThis deposit consists of a 6 foot width of 2- to 3-inch-wide quartz stringers parallel to schistose slate of the Valdez Group of Late Cretaceous age (Nelson and others, 1985). The stringers contain a little arsenopyrite and pyrite. In addition to the stringers, there is abundant vuggy quartz float (Tysdal, 1978 [MF-880-A]). Tuck (1933) sampled the stringer lode, but the assays showed only traces of gold and silver.
|Geologic map unit||(-149.522663818584, 60.8237314899651)|
|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 veins are exposed by prospect pits, and there may be a caved adit (Tysdal, 1978 [MF-880-A]). Tuck (1933) sampled across the vein stringers, but the assays indicated only traces of gold and silver.|
|Indication of production||Undetermined|
|Production notes||The U.S. Bureau of Mines reported a recorded production of 150 ounces of gold (Jansons and others, 1984). This might include production from the Whistler (SR020) and Francisco (SR017) prospects, as well as the Bonanza.|
Additional commentsIn his description of this deposit, Tuck (1933) also included references to the Whistler (SR020), Francisco (SR017), and to another (unnamed) prospect on Bonanza Creek. The Bonanza property is about halfway between the Francisco and Whistler properties. The Francisco, Whistler, and Bonanza are also known as the Downing mine (Jansons and others, 1984). Tysdal (1978 [MF-880-A]) considered these to be separate prospects.
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.
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.
Mitchell, P.A., 1979, Geology of the Hope-Sunrise (gold) mining district, north-central Kenai Peninsula, Alaska: Stanford University Master of Science thesis, 123 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||2/20/2000|