Spruce Creek

Producer in Alaska, United States with commodities Gold, Silver

Geologic information

Identification information

Deposit ID 10308980
MRDS ID A015014
Record type Site
Current site name Spruce Creek
Related records 10002578, 10137172

Geographic coordinates

Geographic coordinates: -156.52937, 63.09224 (WGS84)
Relative position Spruce Creek is a northeast-flowing tributary to the Innoko River. The junction of Spruce Creek and the Innoko River is approximately 2 miles southeast of the town of Ophir. The coordinates are for the approximate midpoint of tailings shown on the U.S. Geological Survey Ophir A-2 topographic map (1954, minor revisions 1965), in sec. 2, T. 28 S., R. 12 E., Kateel River Meridian. Spruce Creek is locality 17 of Cobb (1972 [MF 367]). This location is accurate. Also see Tamarack Creek (OP027), a small tributary to Spruce Creek.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary

Materials information

Materials Type of material
Chromite Ore
Gold Ore
Ilmenite Ore
Magnetite Ore

Mineral occurrence model information

Model code 119
USGS model code 39a
BC deposit profile C01. C02
Deposit model name Placer Au-PGE
Mark3 model number 54

Nearby scientific data

(1) -156.52937, 63.09224

Comments on the geologic information

  • Geologic Description = The bedrock in the vicinity of Spruce Creek mainly of slate cut by highly altered dacitic (?) dikes (Maddren, 1910; Mertie, 1936). Cretaceous or Tertiary monzonite intrusive bodies may also occur in the stream drainage (Bundtzen and others, 1987). Most of the gold in Spruce Creek is in bedrock crevices on low benches (Maddren, 1911; Eakin, 1914; Mertie, 1936). The overburden was about 10 to 15 thick over 2 to 6 feet of auriferous gravels (Eakin, 1914). Some of the gold recovered was very coarse, and included at least one 16-ounce nugget was recovered (Mertie, 1936). The gold at Spruce Creek is 870.7 fine, with 100.3 parts silver, and 29.0 parts impurities (Bundtzen and others, 1987). Smith (1941) reports that gold from Spruce Creek averages 879 fine; Metz and Hawkins (1981) report a fineness of 873. Heavy minerals identified in a pan-concentrate sample from Spruce Creek include magnetite, chromite, ilmenite, orthoferrosilite, reibeckite, and fluorapatite. This sample was collected just downstream from a swarm of peraluminous dikes that contain up to 6% chromite (Bundtzen and others, 1987). The source of the gold is probably these peraluminous dikes, along with some contribution from monzonite intrusions (Bundtzen and others, 1987). Gold was discovered in Spruce Creek in 1907, but there is no record of production until 1910 (Maddren, 1909; Maddren, 1910; Maddren, 1911). Mining was nearly continuous between 1910 and 1940 (Cobb, 1976 [OFR 76-576]). After 1940, reports of mining along Spruce Creek are sporadic. There probably has been more recent production. A conservative estimate of production from Spruce Creek from 1909 to 1950 and 1955 to 1986 is 35,400 ounces of gold and 4,600 ounces of silver (Bundtzen and others, 1987). Also see OP018, 019, 021, 027, and 030.
  • Age = Quaternary. The sources of the placer gold probably are Cretaceous or Tertiary peraluminous dikes, along with some contributions from monzonite intrusive bodies in the Spruce Creek drainage basin (Bundtzen and others, 1987).

Economic information

Economic information about the deposit and operations

Development status Producer
Commodity type Metallic

Comments on exploration

  • Status = Active?

Mining district

District name Innoko

Comments on the production information

  • Production Notes = A conservative estimate of production from Spruce Creek from 1909 to 1950 and 1955 to 1986 is 35,400 ounces of gold and 4,600 ounces of silver (Bundtzen and others, 1987).

Comments on the workings information

  • Workings / Exploration = Gold was discovered in Spruce Creek in 1907, but there is no record of production until 1910 (Maddren, 1909; Maddren, 1910; Maddren, 1911). Mining was nearly continuous between 1910 and 1940 (Cobb, 1976 [OFR 76-576]). After 1940, reports of mining are sporadic. Williams (1950) reports that Matheson and Savage's dragline-dozer-hydraulic operation (Fowler, 1950) on Spruce Creek closed in 1950 due to the son's induction into the army. Assessment work is reported in 1959 (Saunders, 1960). There probably has been more recent production.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF OP026
USGS Mineral Resources Data System MRDS A010751
USGS Mineral Resources Data System MRDS A015014

Bibliographic references

  • Deposit

    Maddren, A.G., 1909, Gold placers of the Innoko district: U.S. Geological Survey Bulletin 379, p. 238-266.

  • Deposit

    Maddren, A.G., 1911, Gold placer mining developments in the Innoko-Iditarod region: U.S. Geological Survey Bulletin 480, p. 236-270.

  • Deposit

    Eakin, H.M., 1914, The Iditarod-Ruby region, Alaska: U.S. Geological Survey Bulletin 578, 45 p.

  • Deposit

    Mertie, J.B., Jr., 1936, Mineral deposits of the Ruby-Kuskokwim region, Alaska: U.S. Geological Survey Bulletin 864-C, 115-245.

  • Deposit

    Williams, J.A., 1950, Mining operations in the Fairbanks district and Innoko and Koyukuk precincts: Alaska Territorial Department of Mines Miscellaneous Report 194-13, 20 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Ophir quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-367, 1 sheet, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction material) in the Iditarod and Ophir quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-576, 101 p.

  • Deposit

    Metz, P.A., and Hawkins, D.B., 1981, A summary of gold fineness values from Alaska placer deposits: University of Alaska, Fairbanks, Mineral Industry Research Laboratory Report No. 45, 63 p.

  • Deposit

    Chapman, R.M., Patton, W.W., and Moll, E.J., 1985, Reconnaissance geologic map of the Ophir quadrangle, Alaska: U.S. Geological Survey Open-File Report 85-203, 1 sheet, 1:250,000 scale.

  • Deposit

    Bundtzen, T.K., Green, C.B., Deagen, J., and Daniels, C.L., 1987, Alaska's mineral industry, 1986: Alaska Division of Geological and Geophysical Surveys, Special Report 40, 68 p.

  • Deposit

    Fowler, H.M., 1950, Report of investigations in the Innoko, Nulato, Bethel, Goodnews Bay, Wasilla, Chisana, and Ketchikan mining districts: Alaska Territorial Department of Mines Itinerary Report 195-7, 13 p.

  • Deposit

    Maddren, A.G., 1910, The Innoko gold-placer district, Alaska, with accounts of the central Kuskokwim valley and the Ruby Creek and Gold Hill placers: U.S. Geological Survey Bulletin 410, 87 p.

  • Deposit

    Saunders, R.H., 1960, Itinerary report on a trip to the Flat and Ophir Districts: Alaska Territorial Department of Mines Itinerary Report 64-2, 15 p.

  • Deposit

    Smith, P.S., 1941, Mineral industry of Alaska in 1939: U.S. Geological Survey Bulletin 926-A, p. 1-106.

Comments on the references

  • Primary Reference = Cobb, 1976 (OFR 76-576)

General comments

Subject category Comment text
Deposit Model Name = Placer Au (on benches) (Cox and Singer, 1986; model 39a)

Reporter information

Type Date Name Affiliation Comment
Reporter 07-AUG-01 Cameron, C.E. Northern Associates Inc.