|Quadrangle map, 1:250,000-scale||DN|
|Quadrangle map, 1:63,360-scale||C-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||
The Little Annie and contiguous Little Annie No. 2 claims (Cobb, 1980 [OFR 80-363]) are at an average elevation of about 2800 feet on the north slope of Quigley Ridge above upper Friday Creek. The location is at the approximate center of the end line between the Little Annie and Little Annie No. 2 claims. This point is within 500 feet of the main workings on each of the two claims. The location is accurate within about 300 feet. The Little Annie mine is marked by mine symbols on the 1954 edition of the Mt. McKinley C-2 quadrangle map.Cobb (1972, number 9 [MF 366]), and MacKevett and Holloway (1977, number 7) include the Little Annie and Little Annie No. 2 claims with the nearby Gold Dollar and Golden Eagle claims (DN110) and Polly Wonder claim (DN114). The two Little Annie claims are number 27 of Bundtzen (1981) and 35 of Thornsberry, McKee, and Salisbury (1984). The Little Annie mine is letter G of Hawley and Associates (1978).
The deposit at the Little Annie mine consists of mineralized quartz-carbonate veins in metafelsite and graphitic phyllite of the Spruce Creek sequence. The deposit is near the crest of the Kantishna antiform (DN091). About 1500 feet north of the mine, a high-angle(?) fault juxtaposes the Spruce Creek country rocks against Birch Creek Schist (Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, fig. K-2).
There are two main veins in the mine. The principal vein strikes about N 60 E and dips 65 SE. It was developed by trenches and by more than 500 feet of underground workings driven below the trenches. Most of the workings are on the northeast half of the Little Annie claim. A second vein, called the sulfide vein, strikes about N 20 E and dips about 70 SE. The sulfide vein is thinner but richer than the principal vein. It is exposed about 350 feet south of the main Little Annie adit. By projection, the principal and sulfide veins should intersect near the boundary between the Little Annie and Little Annie No. 2 claims.
The principal vein was developed by a crosscut-drift adit. The vein was as much as 32 feet thick, and was explored by a series of crosscuts driven into the north wall of the drift (Wells, 1933, pl. 31: Note that the north arrow on this plate is reversed and points south). The vein contains pods of argentiferous galena and a little gold. Excluding one high-grade sample, Wells (1933, p. 366) computed the average assay of the principal vein as 0.10 ounce of gold per ton and 2.10 ounces of silver per ton over a length of 468 feet and an average width of 17 feet. Samples collected from a series of trenches above the vein were somewhat richer, possibly because of local supergene enrichment.
In 1983, the U.S. Bureau of Mines drilled one hole to test the principal vein (Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 35, drill logs). The hole (K-3) intersected a 31-foot-thick vein composed mainly of limonite-stained, sheared, gougy quartz containing a little pyrite and arsenopyrite. The vein averaged only 0.023 ounce of gold per ton, but core recovery was poor, and none was recovered from part of the interval. The richest intersect, from 113.3 to 115.5 feet, assayed 0.094 ounce of gold per ton, 5.86 ounces of silver per ton, and 0.42 percent lead. Another 2.2 foot section of the vein assayed 0.086 ounce of gold per ton. Based on the location of the drill hole relative to mine workings, the hole intersected the principal vein below the drift.
The sulfide vein was up to 3 feet thick. It consisted principally of siderite and calcite containing galena and tetrahedrite. The vein assayed as much as 286 ounces of silver per ton and 0.5 ounce of gold per ton (Brooks and Martin, 1921; Brooks, 1922; Davis, 1923). Essentially all of the ore produced at the Little Annie mine came from this vein.Wells (1933, p. 365) identified chalcopyrite, tetrahedrite, pyrite, arsenopyrite, and small specks of free gold in polished sections of galena and sphalerite from the principal vein. Buntzen (1981, including plate 3) identified polybasite, scheelite, and a rare iron-arsenic secondary mineral called pharmcosiderite.
|Geologic map unit||(, )|
|Mineral deposit model||The principal vein is a low-sulfide gold-quartz vein; the sulfide vein is a polymetallic vein (Cox and Singer, 1986; models 36a and 22c).|
|Mineral deposit model number||36a, 22c|
|Age of mineralization||The deposit is assumed to be Eocene (see record DN091).|
|Alteration of deposit||Possible near-surface supergene enrichment of precious metals. Oxidation of copper minerals.|
|Workings or exploration||Mining began in about 1919, when a shallow shaft and short drift were developed on the (then) Alice claim (Brooks and Martin, 1921). Small-scale mining continued until 1921 (Davis, 1923; Bundtzen, Smith, and Tosdal, 1976). Sometime before 1931, the main drift crosscut and other workings were driven on the principal Little Annie vein. This work may have been done by Kennecott in 1929. W. E. Dunkle optioned the mine to Kennecott in 1928, and in 1929 Be Van Pressley and W. A. Richelson of the Kennecott mine staff undertook significant underground development. Kennecott dropped the claims, but they were reoptioned by General A. D. McRae, who was working for Thayer Lindsley of Ventures, Ltd. They dropped the option in about 1934. Consultant Ira B. Joralemon believed that the ore was cut off at depth by a 'great thrust fault that was hidden on the surface by glacial detritus' (Joralemon, 1976, p. 297-311). The silver-rich ore bodies seemed to pinch out at a depth of about 60 feet, but Wells (1933) believed that this was a structural, not supergene, effect. The claims were reoptioned in 1937 by Franson and Hawkins (Smith, 1939), who built a new mill, but little if any ore was mined at that time. In 1983, the U.S. Bureau of Mines drilled three core holes on the property. A vein intersected in hole K-3 suggests that the principal vein persists at least to shallow depth below the existing mine workings.|
|Indication of production||Yes; small|
|Reserve estimates||Based on sampling reported by Wells (1933), and on U.S. Bureau of Mines drill hole K-3, there is a resource of about 200,000 tons of low-grade gold ore remaining in the principal Little Annie vein.|
|Production notes||Most of the ore mined at Little Annie was produced between 1919 and 1921. About 725 tons mined in that interval contained 117,305 ounces of silver, about 75 ounces of gold, and 148,000 pounds of lead (Bundtzen, Smith, and Tosdal, 1976). Probably this ore was mined by T. P. Aitken on claims optioned from their discoverers, Joe and Fannie Quigley.|
Additional commentsThe mine is in Denali National Park and Preserve and is inactive.
Brooks, A.H., 1922, The Alaska mining industry in 1920: U.S. Geological Survey Bulletin 722-A, p. 1-74.
Brooks, A.H., and Martin, G. C., 1921, The Alaska mining industry in 1919: U.S. Geological Survey Bulletin 714-A, p. 59-95.
Bundtzen, T.K., 1981, Geology and mineral deposits of the Kantishna Hills, Mt. McKinley quadrangle, Alaska: M. S. Thesis, University of Alaska, College, Alaska, 238 p.
Bundtzen, T.K., Smith, T.E., and Tosdal, R.M., 1976, Progress report--Geology and mineral deposits of the Kantishna Hills: Alaska Division of Geological and Geophysical Surveys Open-File Report AOF-98, 80 p., 2 sheets, scale 1:63,360.
Cobb, E. H., 1972, Metallic mineral resources map of the Mount McKinley quadrangle, Alaska: U. S. Geological Survey Miscellaneous Field Studies Map MF-366, 1 sheet, scale 1:250,000.
Cobb, E.H., 1980, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Mount McKinley quadrangle, Alaska: U. S. Geological Survey Open-File Report 80-363, 150 p.
Cox, D.P., and Singer, D.A., eds., 1986, Mineral deposit models: U.S. Geological Survey Bulletin 1693, 379 p.
Davis, J. A., 1923, The Kantishna region, Alaska, in Stewart, B. D., Annual Report of the Mine Inspector to the Governor of Alaska, 1922: Alaska Division of Geological and Geophysical Surveys AR-1922.
Hawley, C. C. and Associates, Inc, 1978, Mineral appraisal of lands adjacent to Mt. McKinley National Park, Alaska: U. S. Bureau of Mines Open-File Report 24-78, 275 p. (paged by sections).
Joralemon, Ira B., 1976, Adventure Beacons: American Institute of Mining and Metallurgy, New York, N. Y., 487 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.
Smith, P.S., 1939, Mineral industry of Alaska in 1937: U.S. Geological Survey Bulletin 910-A, p. 1-113.
Thornsberry, V. V., McKee, C. J., and Salisbury, W. G., eds, 1984, 1983 Mineral Resource Studies: Kantishna Hills and Dunkle Mine Areas, Denali National Park and Preserve, Alaska: U. S. Bureau of Mines Open-File Report 129-84. 3 Volumes: v. 1, Text; v. 2, Appendices; v. 3, Maps. Prepared by Salisbury & Dietz, Inc., Spokane, WA.
|Last report date||4/29/2001|