Shirley Bar Mine, Hot Springs District, Yukon-Koyukuk Borough, Alaska, USA
|Latitude & Longitude (WGS84):||65° 10' 16'' North , 150° 15' 25'' West|
|Latitude & Longitude (decimal):||65.1711111111, -150.256944444|
Location: 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.
Geology: 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).
Workings: 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).
Commodities (Major) - Au; (Minor) - Hg, Pb
Development Status: Yes; small
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a).
6 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
0 - 2.588 Ma
|Unconsolidated surficial deposits, undivided|
Age: Pleistocene (0 - 2.588 Ma)
Reference: Wilson, F.H., Hults, C.P., Mull, C.G, and Karl, S.M. (compilers). Geologic map of Alaska. doi: 10.3133/sim3340. U.S. Geological Survey Scientific Investigations Map 3340, pamphlet 196. 
100.5 - 145 Ma
|Sedimentary; Slope and deep water|
Age: Early Cretaceous (100.5 - 145 Ma)
Description: Eastern Alaska, Yukon, Mackenzie region, Mackenzie Plain
Comments: Sedimentary basin; Wilson & Hults, unpublished compilation, 2007-08
Reference: J.C. Harrison, M.R. St-Onge, O.V. Petrov, S.I. Strelnikov, B.G. Lopatin, F.H. Wilson, S. Tella, D. Paul, T. Lynds, S.P. Shokalsky, C.K. Hults, S. Bergman, H.F. Jepsen, and A. Solli. Geological map of the Arctic. doi:10.4095/287868. Geological Survey of Canada Map 2159A.