|Quadrangle map, 1:250,000-scale||TN|
|Quadrangle map, 1:63,360-scale||A-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Shirley Bar is a bench placer on high ground between Rhode Island and Glen creeks. The site is at the mine symbol just south of the center of the boundary between sections 17 and 18, T. 4 N., R. 13 W., of the Fairbanks Meridian. The location is accurate. The site is included in location 39 of Cobb (1972), and roughly corresponds with U.S. Bureau of Land Management MAS number 0020480094.|
Shirley Bar is a bench placer deposit between Glen Creek and Rhode Island Creek. It is on a broad, gently sloping bedrock spur that is covered with [Pleistocene?] alluvial deposits. The bedrock in the area (and at the workings) is predominantly Cretaceous sandstone, shale, and siltstone (Chapman and others, 1982; Reifenstuhl and others, 1998). A thrust-emplaced lenticular block of Triassic sedimentary rocks and Jurassic or Cretaceous quartzite are mapped to the north and west. No intrusive rocks are exposed in the area.
The bench was originally mined in 1901. Collier (1903) reported that the pay was in the gravel on bedrock and in a clay layer that often lies on the bedrock. Later reports state that the gold is distributed evenly throughout the 2- to 9-foot thickness of gravel in the bench (Prindle and Hess, 1905; Hess, 1908). Mertie (1934) described the deposit as a semi-residual body of auriferous, angular gravel, and that the pay streak continues down the hillside as a body of subangular gravel on muck.
Collier (1903) described the gold as coarse and rough. An assay of the gold yielded a value of $16.45 an ounce (at $20.67 per ounce). Mertie (1934) reported a gold fineness of 792. Other heavy minerals in the placer include pyrite, cinnabar, picotite, barite, galena, ilmenite, limonite, garnet, and sphene (Waters, 1934). Joesting (1942) reported that cinnabar was common.Published reports indicate that by 1904 there had been considerable production from Shirley Bar (Prindle and Hess, 1905). After 1904, mining was recorded in 1931, 1937, and 1938 (Smith, 1933; Smith, 1939 [B 910-A; B 917-A]; Cobb, 1977), and again in 1951 (Williams, 1951). Tony Landing mined in 1962 (Saunders, 1962), and Johnson & Toftaker were active in 1967 (Heiner and others, 1968).
|Geologic map unit||(-150.259632911439, 65.1707916356377)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary.|
|Workings or exploration||The deposit probably was mined by surface workings, and although water was scarce, production was considerable by 1904 (Prindle and Hess, 1905). Sporadic mining occurred after this, with specific references to mining of Shirley Bar published only in 1931, 1937, and 1938 (Smith, 1933; Smith, 1939 [B 10-A; B 917-A]; Cobb, 1977), and in 1951 (Williams, 1951). Tony Landing mined in 1962 (Saunders, 1962), and Johnson & Toftaker were active in 1967 (Heiner and others, 1968).|
|Indication of production||Yes; small|
Chapman, R.M., Yeend, W.E., Brosge, W.P., and Reiser, H.N., 1982, Reconnaissance geologic map of the Tanana quadrangle: U.S. Geological Survey Open-File Report 82-734, 20 p., scale 1:250,000.
Cobb, E.H., 1972, Metallic mineral resources map of the Tanana quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-371, 1 sheet, scale 1:250,000.
Cobb, E.H., 1977, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Tanana quadrangle, Alaska: U.S. Geological Survey Open-File Report 77-432, 98 p.
Collier, A.J., 1903, The Glenn Creek gold mining district, Alaska: U.S. Geological Survey Bulletin 213, p. 49-56.
Heiner, L.E., Wolff, E.N., and Lu, F.C.J., 1968, Mining regions and mineral commodities, in Heiner, L.E., and Wolff, E.N. eds., Final Report - Mineral Resources of Northern Alaska: Mineral Industry Research Laboratory, University of Alaska Report No. 16, p. 3-137.
Hess, F.L., 1908, The Rampart placers, in Prindle, L.M., The Fairbanks and Rampart quadrangles, Alaska: U.S. Geological Survey Bulletin 337, p. 64-98.
Joesting, H.R., 1942, Strategic mineral occurrences in interior Alaska: Alaska Territorial Department of Mines Pamphlet 1, 50 p.
Mertie, J.B., Jr., 1934, Mineral deposits of the Rampart and Hot Springs districts, Alaska: U.S. Geological Survey Bulletin 844-D, p. 163-226.
Prindle, L.M., and Hess, F.L., 1905, Rampart placer region: U.S. Geological Survey Bulletin 259, p. 104-119.
Reifenstuhl, R.R., Dover, J.H., Newberry, R.J., Clautice, K.H., Pinney, D.S., Liss, S.A., Blodgett, R.B., and Weber, F.R., 1998, Geologic map of the Tanana A-1 and A-2 quadrangles, central Alaska: Alaska Division of Geological & Geophysical Surveys Public Data File 98-37A v. 1.1, 19 p., 1 sheet, scale 1:63,360.
Saunders, R.H., 1963, Mining operations in the Rampart, Manley Hot Springs, and Tolovana Districts: Alaska Territorial Department of Mines Itinerary Report 48-2, 7 p.
Smith, P.S., 1933, Mineral industry of Alaska in 1931: U.S. Geological Survey Bulletin 844-A, p. 1-81.
Smith, P.S., 1939, Mineral industry of Alaska in 1937: U.S. Geological Survey Bulletin 910-A, p. 1-113.
Smith, P.S., 1939, Mineral industry of Alaska in 1938: U.S. Geological Survey Bulletin 917-A, p. 1-113.
Waters, A.E., 1934, Placer concentrates of the Rampart and Hot Springs district: U.S. Geological Survey Bulletin 844-D, p. 163-246.
|Reporters||G.E. Graham (ADGGS), D.J. Szumigala (ADGGS)|
|Last report date||8/8/2003|