Fort Knox Gold Mine, Fairbanks North Star Borough, Alaska, USA
|Latitude & Longitude (WGS84):||64° 59' 57'' North , 147° 20' 11'' West|
|Latitude & Longitude (decimal):||64.9992305556, -147.336291667|
Located NE of Fairbanks on the north flank of Gilmore Dome, between Monte Cristo and Melba Creeks.
The Fort Knox gold deposit occurs in a granite body now commonly refered to as the Fort Knox Pluton. Gold occurs along margins of stockwork quartz veins and veinlets, on quartz-filled shear zones, and along fractures within the granite.
Discovered by a geologist walking behind a bulldozer on the Fort Knox claims, who picked up a piece of granite containing visible gold.
First gold bars were poured on Dec. 20, 1996. Total gold recovered as of Jan. 31, 2000 is 1,113,137 ounces. As of 2000, largest gold mine in Alaska, producing 1,000 ounces of gold from 36,000 to 44,000 tons of ore per day. Reserves are estimated at 186 million tons grading 0.027 ozs./ton, or 5.04 million ozs. The gold varies from 948 to 990 fine. Size of the open pit in 2000 was 3,000 feet by 5,000 feet.
17 valid minerals.
GeochronologyMineralization age: Late Cretaceous : 93.4 Ma to 91.5 Ma
Important note: This table is based only on rock and mineral ages recorded below and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.
|Geologic Time||Rocks, Minerals and Events|
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)
Description: Massive, homogeneous unconsolidated, well-sorted silt of eolian origin containing less than 10% clay, locally rich in organic silt and larger organic fragments. Inorganic components are angular grains of quartz, feldspar, and mica, locally cemented by iron oxides. It is buff to brown or gray, locally mottled. Organic silt is brown to grayish black
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. 
|Devonian - Cambrian|
358.9 - 541 Ma
|Sedimentary; Sedimentary: undivided|
Age: Paleozoic (358.9 - 541 Ma)
Description: Eastern Alaska, Yukon, Mackenzie region, Yukon-Tanana upland
Comments: Orogen, magmatic arc/suite; 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. 
- Thompson, J.F.H., Sillitoe, R.H., Baker, T., Lang, J.R., and Mortensen, J.K. (1999): Intrusion-related gold deposits associated with tungsten-tin provinces. Mineralium Deposita 34, 323-334.