|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 Humboldt mine (Cobb, 1980 [OFR 80-363]) is at an elevation of about 4100 feet on the east flank of a ridge above the East Fork of Glen Creek . It is in the NE1/4 NE1/4 section 36, T. 15 S., R. 17 W., Fairbanks Meridian. The location is probably accurate within 500 feet. The mine is number 20 of Cobb (1972 [MF 366]), 56 of Bundtzen, Smith and Tosdal (1976), 61 of Bundtzen (1981), and 78 of Thornsberry, McKee, and Salisbury (1984).|
The Humboldt (also Humbolt) mine is in the Birch Creek Schist, probably a short distance west of a nearly vertical fault that strikes NE and juxtaposes Birch Creek and Spruce Creek rocks. Subunits of the Birch Creek Schist at the mine include quartz-chlorite-biotite schist, micaceous quartzite, garnet schist, and quartz-chlorite-muscovite schist (Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, fig. K-2 and v. 2, occurrence 78). The schistosity strikes N37W and dips 27 SW (Capps, 1919, p. 99).The deposit consists of a series of quartz veins in a zone 22 to 50 feet wide. A short adit was driven on a nearly vertical vein about 4 feet wide that strikes N55E. The wall rocks adjoining the zone are impregnated with siderite and locally stained with malachite. The veins contain pyrite, pyrrhotite, galena, sphalerite, stibnite(?), minor arsenopyrite, and free gold (Moffit, 1933, p. 333; Bundtzen, 1981; Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 78). A composite representative sample across about 15 feet of the mineralized zone assayed 1.02 ounces of gold per ton, 0.27 ounce of silver per ton, and 0.046 percent arsenic. A sample of limonitic gossan assayed 3.69 ounces of silver per ton, 1.45 percent lead, and 2. 10 percent zinc (Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 78).
|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).|
|Alteration of deposit||Carbonate alteration of wallrocks; silicification; oxidation of iron and copper minerals.|
|Workings or exploration||The deposit was developed by a tunnel about 50 feet long and by surface cuts. The tunnel was caved by 1916 (Capps, 1919). Probably not much work has been done since then.|
|Indication of production||Yes; small|
|Production notes||Gold reportedly was recovered from a test shipment of several hundred pounds of selected, quartz-rich ore.|
Additional commentsThe Humboldt mine 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.
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.
Moffit, F.H., 1933, The Kantishna district, in Smith, P.S. and others, Mineral resources of Alaska: report on investigations in 1930, U. S. Geological Survey Bulletin 836, p. 301-338.
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||5/3/2001|