Grubstake Creek Mine, Bonnifield Mining District, Denali Borough, Alaska, USA i
Regional Level Types
Grubstake Creek Mine Mine
Bonnifield Mining District Mining District
Denali Borough Borough
Alaska State
USA Country

Location: The Grubstake Creek mine is loated in sections 19, 20, and 29, T. 10 S., R. 3 W., Fairbanks Meridian. Placer mines on Grubstake Creek are marked in the southeast corner of the Fairbanks A-3 topographic map; the coordinates are the mine marked near the mouth of the creek. The mine is localities 77, 78, and 79 of Cobb (1972 [MF 410].
Geology: The upper half of Grubstake Creek valley is incised into thick Nenana Gravel; the lower half of the creek has eroded through the base of the Nenana Gravel to a depth of 100 feet or more into semiconsolidated sediments composed of interbedded clay, sand, and gravel, and some thin beds of lignite (Maddren, 1918, p. 399). Since its discovery in 1905, Grubstake Creek has been a major producer of placer gold in the Tatlanika basin. Mining began as early as 1905 and continued intermittently until at least 1940 (Cobb, 1976 [OFR 76-662, p. 44]). Gold is found as small, worn, flat pieces in the bottom two feet of gravel or on the clay bedrock (Prindle, 1907). The gold varies from 817 to 842 fine (Glover, 1950). The gravels are as much as 6 feet thick and include clasts of schist, quartzite, and vein quartz (Prindle, 1907). Scheelite and cinnabar have been found in placer concentrates (Joesting, 1942 [ATDM Pamph. 1, p. 27]).
Workings: Mining began as early as 1905 and continued intermittently until at least 1940 (Cobb, 1976 [OFR 76-662, p. 44]). In 1924, three men mined on the creek with an automatic dam (Wimmler, 1925 [ATDM MR 195-8, p. 43]).
Age: Quaternary placer.
Production: There is no record of the amount of gold that was produced.

Commodities (Major) - Au; (Minor) - Hg, W
Development Status: Yes; small
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a)

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

ⓘ Mercury

ⓘ Tungsten

Mineral List

ⓘ Cinnabar

ⓘ Native Gold

ⓘ Scheelite

3 valid minerals.

Detailed Mineral List:

ⓘ Cinnabar

Formula: HgS

References:

(2008) Alaska Resource Data File (ARDF) Open-File Report 2008-1225. US Geological Survey

ⓘ Native Gold

Formula: Au

References:

(2008) Alaska Resource Data File (ARDF) Open-File Report 2008-1225. US Geological Survey

ⓘ Scheelite

Formula: Ca(WO₄)

References:

(2008) Alaska Resource Data File (ARDF) Open-File Report 2008-1225. US Geological Survey

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘ	Native Gold	1.AA.05	Au
Group 2 - Sulphides and Sulfosalts
ⓘ	Cinnabar	2.CD.15a	HgS
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘ	Scheelite	7.GA.05	Ca(WO₄)

List of minerals for each chemical element

O	Oxygen
O	ⓘ Scheelite	Ca(WO₄)
S	Sulfur
S	ⓘ Cinnabar	HgS
Ca	Calcium
Ca	ⓘ Scheelite	Ca(WO₄)
W	Tungsten
W	ⓘ Scheelite	Ca(WO₄)
Au	Gold
Au	ⓘ Native Gold	Au
Hg	Mercury
Hg	ⓘ Cinnabar	HgS

Other Databases

Link to USGS - Alaska:	FB145

Other Regions, Features and Areas containing this locality

North AmericaContinent

North America PlateTectonic Plate

Nenana BasinBasin
North America PlatformPassive Margin
Yukon-Tanana lower DomainDomain

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References

Brooks, A.H., 1910, Mineral resources of Alaska, report on progress of investigations in 1909: U.S. Geological Survey Bulletin 442, 426 p. Brooks, A.H., 1911, The Mount McKinley region, Alaska, with descriptions of the igneous rocks and of the Bonnifield and Kantishna districts by L.M. Prindle: U.S. Geological Survey Professional Paper 70, 234 p. Brooks, A.H., 1923, The Alaska mining industry in 1921: U.S. Geological Survey Bulletin 739-A, p. 1-50. Capps, S.R., 1911, Mineral resources of the Bonnifield region: U.S. Geological Survey Bulletin 480-H, p. 218-235. Capps, S.R., 1912, The Bonnifield region, Alaska: U.S. Geological Survey Bulletin 501, 64 p., 1 sheet, scale 1:250,000. Cobb, E.H., 1972, Metallic mineral resources map of the Fairbanks quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-410, 1 sheet, scale 1:250,000. Cobb, E.H., 1973, Placer deposits of Alaska: U.S. Geological Survey Bulletin 1374, 213 p. Cobb, E.H., 1975, Mineral resources of Alaska, in Yount, M.E., ed., U.S. Geological Survey Alaska Program, 1975: U.S. Geological Survey Circular 722, p. 37. Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Fairbanks quadrangle, Alaska: U.S. Geological Survey Open-File Report 76-662, 174 p. Glover, A.E., 1950, Placer gold fineness: Alaska Territorial Department of Mines Miscellaneous Report 195-1, 38 p. Joesting, H.R., 1942, Strategic mineral occurences in interior Alaska: Alaska Territorial Department of Mines Pamphlet 1, 46 p. Maddren, A.G., 1918, Gold placers near the Nenana coal field: U.S. Geological Survey Bulletin 662-G, p. 363-402. Malone, Kevin, 1962, Mercury occurrences in Alaska: U.S. Bureau of Mines Circular 8131, 57 p. Malone, Kevin, 1965, Mercury in Alaska, in Mercury potential of the United States: U.S. Bureau of Mines Information Circular 8252, p. 31-59. Moffit, F.H., 1933, Mining developments in the Tatlanika and

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