|Quadrangle map, 1:250,000-scale||MM|
|Quadrangle map, 1:63,360-scale||C-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is on the east side of Spruce Peak, probably within 800 feet of the top. The location is uncertain. For this record, it corresponds to occurrence 88 of Thornsberry, McKee, and Salisbury (1984, fig. K-8), which is near the center of the E1/2 SW1/4 section 29, T. 15 S., R. 16 W., Fairbanks Meridian.|
Geologic descriptionAt this occurrence, a weakly mineralized reverse(?) fault places metafelsite on the south against highly deformed graphitic schist or phyllite. Both rock types are probably units of the lower Paleozoic Spruce Creek sequence (Bundtzen, 1981). The fault zone is about 10-15 feet wide. It strikes about N 55 E and dips 65-75 N, and contains quartz -calcite veins. The zone and nearby country rocks are stained with limonitic minerals, including goethite and jarosite. The limonite probably replaces pyrite or arsenopyrite. Samples of the oxidized vein contain up to 1400 ppm arsenic, along with a trace each of gold and silver (Thornsberry, McKee, and Salisbury, 1984, v. 2, occurrence 88).
|Geologic map unit||(-150.698883908611, 63.5808996801812)|
|Mineral deposit model||Low-sulfide Au-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 MM091).|
|Alteration of deposit||Silicification of a fault zone. Iron-oxide alteration.|
|Workings or exploration||There are no workings. The oxidized fault zone can be traced in outcrop (rubblecrop?) for several tens of feet.|
|Indication of production||None|
Additional commentsThis occurrence 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.
Cox, D.P., and Singer, D.A., eds., 1986, Mineral deposit models: U.S. Geological Survey Bulletin 1693, 379 p.
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||5/4/2001|