|Quadrangle map, 1:250,000-scale||IL|
|Quadrangle map, 1:63,360-scale||C-3|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Duryea prospect is at an elevation of about 2,000 feet at the head of an unnamed north fork of Silver Creek. It is about 3.5 miles up the Native Trail that connects Meadow Lake with the old Iliamna village site. The prospect is mainly in the NW1/4 SW1/4 sec. 5, T. 6 S., R. 27 W., Seward Meridian, but it may extend west into section 6. The location is probably accurate within 0.5 mile. The Duryea prospect is number 6 of Detterman and Cobb (1972).|
The country rocks at the Duryea prospect are the Upper Triassic Bruin Limestone Member of the Kamishak Formation, and greenstone that conformably underlies(?) the limestone (Detterman and Reed, 1980). The Bruin Limestone strikes northeast and consists mainly of massive- to thin-bedded, light- to dark-gray limestone interbedded with banded green and white chert. The limestone and greenstone are intruded by a myriad of vertical dikes that crosscut the formation and by larger dikes and sills that parallel the strike of the limestone (Martin and Katz, 1910, 1912).The mineral occurrences apparently are vein and replacement deposits in limestone. Exposures and shallow pits aligned about N45E suggest a fault-controlled mineralized zone about 5,000 feet long, marked by gossan of manganiferous iron oxide and limonite. The most abundant ore minerals below the oxidized zone appear to be sphalerite, galena, pyrite, and minor amounts of chalcopyrite. Brooks (1913) was told of arsenopyrite on the property. Martin and Katz (1912) reported owner's claims of samples assaying 80 to 196 ounces of silver per ton, about 1 ounce of gold per ton, 35 to 50 percent lead, and 15 to 20 percent zinc.
|Geologic map unit||(-153.924855505146, 59.6851348304001)|
|Mineral deposit model||Zn-Pb skarn? (Cox and Singer, 1986; model 18c).|
|Mineral deposit model number||18c?|
|Age of mineralization||Late Triassic or younger.|
|Alteration of deposit||Skarn-like replacement of limestone. Oxidation of sulfide minerals.|
|Workings or exploration||Claims were first located in about 1901-02 (Martin and Katz, 1910). Brooks (1913) reported that two tunnels were driven and intersected ore at a depth of 150 feet. Development work, including plans for a test shipment, trail improvements, and underground development, probably continued through 1922 (Brooks, 1914, 1915, 1923; Brooks and Capps, 1924). Moxham and Nelson (1952) reported that the underground workings had caved prior to their investigation in 1949, and Butherus and others (1981) could find no certain evidence of the deposits at the Duryea, although they reported mineralization in the area.|
|Indication of production||None|
Bain, H.F., 1946, Alaska's minerals as a basis for industry: U.S. Bureau of Mines Information Circular 7379, 89 p.
Berg, H.C., and Cobb, E.H., 1967, Metalliferous lode deposits of Alaska: U.S. Geological Survey Bulletin 1246, 254 p.
Brooks, A.H., 1913, Mineral resources of Alaska, report on progress of investigations in 1912: U.S. Geological Survey Bulletin 542, 308 p.
Brooks, A.H., 1914, Mineral resources of Alaska; report on progress of investigations in 1913: U.S. Geological Survey Bulletin 592, 413 p.
Brooks, A.H., 1915, Mineral resources of Alaska; report on progress of investigations in 1914: U.S. Geological Survey Bulletin 622, 380 p.
Brooks, A.H., 1923, The Alaska mining industry in 1921: U.S. Geological Survey Bulletin 739-A, p. 1-50.
Brooks, A.H., and Capps, S.R., 1924, The Alaska mining industry in 1922: U.S. Geological Survey Bulletin 755-A, p. 1-56.
Butherus, D. L, White, D. C., Smith, W. H., Radford, Geoff, Sandberg, R. J., and Pray, J. C., 1981, Exploration and evaluation of precious metals potential of Bristol Bay Native Corporation lands, southwest Alaska, v. 1: Resource Associates of Alaska, Fairbanks, Alaska. (Report on file, Bristol Bay Native Corporation, Anchorage, Alaska).
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.
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.
Martin, G.C., and Katz, F.J., 1910, Outline of the geology and mineral resources of the Iliamna and Clark lakes region: U.S. Geological Survey Bulletin 442-E, p. 179-200.
Martin, G.C., and Katz, F.J., 1912, A geologic reconnaissance of the Iliamna region, Alaska: U.S. Geological Survey Bulletin 485, 138 p.
Moxham, R.M., and Nelson, A.E., 1952, Reconnaissance for radioactive deposits in the southern Cook Inlet region, Alaska, 1949: U.S. Geological Survey Circular 207, 7 p., 1 plate, scale 1:500,000.
|Reporters||C.C. Hawley, Hawley Resource Group, Anchorage, Alaska|
|Last report date||6/6/2003|