|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 Francis mine (Cobb, 1980 [OFR 80-363]) is on the southwest crest of Quigley Ridge at an elevation of about 2800 feet. The coordinates are for the location of the mine adit, and are accurate within about 300 feet.The Francis mine is included with the Lucky Strike prospect (DN135) in location 5 of Cobb (1972 [MF 366]) and in number 4 of MacKevett and Holloway (1977). The mine is included in number 23 of Bundtzen (1981) and number 31 of Thornsberry, McKee, and Salisbury (1984). It is patented claim 13 of Hawley and Associates (1978).
Geologic descriptionThe country rock on the Francis claim consists of metafelsite and graphitic phyllite of the Spruce Creek sequence (Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, fig. K-2, also v. 2, location 31). The deposit is a 1- to 3.5-foot-thick mineralized quartz vein that strikes N. 55 E., and dips about 65 S. It can be followed in old workings and pits for several hundred feet and projects towards a vein of similar strike and dip on the adjacent Little Maud claim (DN119). The vein is mostly white quartz containing some pyrite and copper sulfide. Samples from the Francis vein collected by Davis (1923) and Wells (1933) were low grade, but Wells noted that some of the quartz contains visible free gold. Davis (1924) noted that the owners of the property reported finding vein material valued at about $35, or about 1.75 ounce of gold, per ton. Bundtzen (1981) reported another vein on the property that strikes about N75E and dips vertically.
|Geologic map unit||(, )|
|Mineral deposit model||Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).|
|Mineral deposit model number||36a|
|Age of mineralization||The deposit is assumed to be Eocene (see record DN091).|
|Workings or exploration||The Francis vein was developed by a drift adit about 70-75 feet long that was probably driven before 1920. The Francis claim area was explored by Moneta-Porcupine in 1960-61 (Seraphim, 1962).|
|Indication of production||Yes; small|
|Production notes||Bundtzen (1981) reported that a few tons of ore were produced from the Francis mine. Presumably, this ore was the richer, free-gold bearing, material reported by Davis (1923) and Wells (1933).|
Additional commentsThe claim is in Denali National Park and Preserve.
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.
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).
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.
Seraphim, R.H., 1962, Kantishna District: Alaska Division of Mines and Minerals Miscellaneous Report 193-3, 11 p., 10 sheets.
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||4/22/2001|