Tamarack Creek Mine, Innoko District, Yukon-Koyukuk Borough, Alaska, USA
|Latitude & Longitude (WGS84):||63° 5' 40'' North , 156° 31' 15'' West|
|Latitude & Longitude (decimal):||63.09444,-156.52083|
Location: Tamarack Creek is a short, northwest-flowing tributary of Spruce Creek; Spruce Creek is about 3.5 miles south of Ophir. The coordinates are at the placer mine marked near the mouth of Tamarack Creek on the U.S. Geological Survey Ophir A-2 topographic map (1954, minor revisions 1965), in NW1/4 sec. 2, T. 28 S., R. 12 E., Kateel River Meridian. Tamarack Creek is locality 18 of Cobb (1972 [MF 367]). The location is accurate within 100 feet.
Geology: The rocks in the vicinity of Tamarack creek are shale and siltstone. The creek probably also drains Cretaceous or Tertiary monzonite plutons, and dikes of various compositions (Chapman and others, 1985). These intrusive rocks probably are the source of the placer gold in Tamarack Creek (Bundtzen and others, 1987). Heavy minerals in pan concentrates from Tamarack Creek include magnetite, ilmenite, pyrite, pyroxene, amphibole, and several grains of native silver (Bundtzen and others, 1987). Mertie (1936) reports that a paystreak yielding good returns was being mined in 1934. Production from Tamarack Creek probably is combined with production figures for Spruce Creek (OP026).
Workings: Mertie (1936) reports that a paystreak yielding good returns was being mined in 1934.
Production: Production from Tamarack Creek probably is combined with production for Spruce Creek (OP026).
Commodities (Major) - Au; (Minor) - Ag
Development Status: Yes; small
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a)
5 valid minerals.
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: Chiefly silt and very fine sand including thick deposits of micaeous silt in the Koyukuk Flats and Nowitna and Innoko Lowlands. Local deposits of alluvial fan and glacial outwash gravels. Widespread in lowland areas throughout the central and southern parts of the map area
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. 
|Maastrichtian - Campanian|
66 - 83.6 Ma
|Sedimentary; Sedimentary: undivided|
Age: Late Cretaceous (66 - 83.6 Ma)
Description: Interior western Alaska, Southwest Basin
Comments: Sedimentary basin; 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.