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Portage Creek

Producer in Alaska, United States with commodities Gold, Bismuth, Copper, Tin, Uranium, Tungsten, Zinc
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Geologic information

Identification information

Deposit ID 10308817
MRDS ID A012236
Record type Site
Current site name Portage Creek
Related records 10001481, 10281576

Geographic coordinates

Geographic coordinates: -144.61591, 65.46174 (WGS84)
Relative position The placered area extends about 3/4 mile up and downstream from the intersection of the coordinates. Portage Creek flows in a northeasterly direction and can be accessed by gravel road just a few miles east of Circle Hot Springs.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Bismuth Secondary
Copper Secondary
Tin Secondary
Uranium Secondary
Tungsten Secondary
Zinc Secondary

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) -144.61591, 65.46174
ListMap

Comments on the geologic information

  • Geologic Description = Portage Creek near its source is underlain by Cretaceous granite, then flows over chorite-muscovite schist and Tertiary granite before crossing into the Tintina fault zone. Almost all of the mining has been conducted south (upstream) of the Tintina fault zone. Gold is restricted to the upper 0.5 meters of the orange, schist-rich gravel. A high percentage of the detritus in Portage Creek is colluvium, so the mined gravel is poorly sorted (Yeend, 1991). One meter of muck typically overlies 2 meters of colluvial-alluvial gravel. A defined 'paystreak' is not often present due to the colluvial mixing and lack of alluvial water to wash and sort. Because of the thick colluvial gravel cover on the side slopes, the mined gravel channel is quite narrow, only 20 to 30 meters (Yeend, 1991). Placer concentrates contain allanite, arsenopyrite, bismuthinite, cassiterite, garnet, gold, hematite, ilmenite, magnetite, monazite, pyrite, scheelite, sphalerite, sphene, spinel, topaz, tourmaline, uranothorianite, wolframite and zircon (Nelson and others, 1954). Gold was not discovered on the creek until the early 1900's (Brooks, 1907). Full-scale mining did not begin on the creek until 1933. Two miners worked the upper valley in 1936. One operation consisted of drift mining and one was a prospecting shaft (Mertie, 1938). Gravel valued at 0.025 to 0.0625 ounces per cubic yard was being mined in 1937 by several miners shoveling in an opencut (Lampright, 1996, p. 74). There were two operations on the creek in 1975 and anywhere from two to five operations per year during the 1980's (Yeend, 1991). Points North operation on Portage Creek was the biggest producer of gold in the Circle district in 1994 (Swainbank and others, 1994, p. 28). Ten ounces of gold were reportedly recovered from one claim on the creek in 1906 (Brooks, 1907, p. 198) and various mines have been operating on and off to the present. Points North operation on Portage Creek was the biggest producer of gold in the Circle district in 1994 (Swainbank and others, 1994, p. 28).

Economic information

Economic information about the deposit and operations

Development status Producer
Commodity type Metallic

Comments on exploration

  • Status = Active

Mining district

District name Circle

Comments on the production information

  • Production Notes = Ten ounces of gold were reportedly recovered from one claim on the creek in 1906 (Brooks, 1907, p. 198) and various mines have been operating on and off to the present. Points North operation on Portage Creek was the biggest producer of gold in the Circle district in 1994 (Swainbank and others, 1994, p. 28).

Comments on the workings information

  • Workings / Exploration = Gold was not discovered on the creek until the early 1900's (Brooks, 1907). Full-scale mining did not begin on the creek until 1933. Two miners worked the upper valley in 1936. One operation consisted of drift mining and one was a prospecting shaft (Mertie, 1938). Gravel valued at 0.025 to 0.0625 ounces per cubic yard was being mined in 1937 by several miners shoveling in an opencut (Lampright, 1996, p. 74). There were two operations on the creek in 1975 and anywhere from two to five operations per year during the 1980's (Yeend, 1991). Points North operation on Portage Creek was the biggest producer of gold in the Circle district in 1994 (Swainbank and others, 1994, p. 28).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF CI047
USGS Mineral Resources Data System MRDS A012236
USGS Mineral Resources Data System MRDS D002687

Bibliographic references

  • Deposit

    Brooks, A.H., 1907, The Alaskan mining industry in 1906: U.S. Geological Survey Bulletin 314, p. 19-39.

  • Deposit

    Ellsworth, C.E., and Davenport, R.W., 1913, Placer mining in the Yukon-Tanana region: U.S. Geological Survey Bulletin 542, 303 p.

  • Deposit

    Smith, P.S., 1934, Mineral industry of Alaska in 1933: U.S. Geological Survey Bulletin 864-A, p. 1-94.

  • Deposit

    Smith, P.S., 1938, Mineral industry of Alaska in 1936: U.S. Geological Survey Bulletin 897-A, p. 1-107.

  • Deposit

    Smith, P.S. 1939, Mineral industry in Alaska in 1937: U.S. Geological Survey Bulletin 910-A, p. 1-113.

  • Deposit

    Smith, P.S., 1939, Mineral industry of Alaska in 1938: U.S. Geological Survey Bulletin 917-A, p. 1-113.

  • Deposit

    Bates, R.G. and Wedow, H. Jr., 1953, Preliminary summary review of thorium-bearing mineral occurrences in Alaska: U.S. Geological Survey Circular 202, 13 p.

  • Deposit

    Wedow, Helmuth, Jr., 1953, Preliminary summary of reconnaissance for uranium and thorium in Alaska, 1952: U.S. Geological Survey Circular 248, 15 p.

  • Deposit

    Nelson, A.E., West, W.S., and Matsko, J.J., 1954, Reconnaissance for radioactive deposits in eastern Alaska: U.S. Geological Survey Circular 348, 21 p.

  • Deposit

    Wedow, Helmuth, Jr., Killeen, P. L., and others, 1954, Reconnaissance for radioactive deposits in eastern interior Alaska, 1946: U.S. Geological Survey Circular 331, 36 p.

  • Deposit

    Berg, H.C., and Cobb, E.H., 1967, Metalliferous Lode Deposits of Alaska. U.S. Geological Survey Bulletin 1246, 254 p.

  • Deposit

    Overstreet, W.C., 1967, The geologic occurrence of monazite: U.S. Geological Survey Professional Paper 530, 327 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Circle quadrangle, Alaska: U.S. Geological Survey Misc. Field Studies Map MF-391, 1 sheet, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1973, Placer deposits of Alaska: U.S. Geological Survey Bulletin 1374, 213 p.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Circle quadrangle, Alaska: U.S. Geological Survey Open-File Report 76-633, 72 p.

  • Deposit

    Eakins, G.R., Jones, B.K. and Forbes, R.B., 1977, Investigation of Alaska's uranium potential: Alaska Division of Geological and Geophysical Surveys Open-File Report 109, 213 p., 10 sheets, scale 1:40,000.

  • Deposit

    Menzie, W.D., Foster, H.L., Tripp, R.B., and Yeend, W.E., 1983, Mineral resource assessment of the Circle quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-170-B, 61 p., 1 sheet, 1:250,000.

  • Deposit

    Yeend, W.E., 1991, Gold placers of the Circle district, Alaska - past, present, and future: U.S. Geological Survey Bulletin 1943, 42 p.

  • Deposit

    Swainbank, R.C., Bundtzen, T.K., Clough A.H., Henning, M.W., and Hansen E.W., 1994, Alaska's mineral industry 1994: Alaska Division of Geological and Geophysical Surveys Special Report 49, 77 p.

  • Deposit

    Lampright, R.L., 1996, Gold placer deposits near Fairbanks Alaska: Iron Fire Publications, Nederland, Colorado, 135 p.

  • Deposit

    Chapin, Theodore, 1914, Placer mining in the Yukon-Tanana region: U.S. Geological Survey Bulletin 592-J, p. 357-362.

  • Deposit

    Smith, P.S., 1939, Mineral industry of Alaska in 1937: U.S. Geological Survey Bulletin 910-A, p. 1-113.

Comments on the references

  • Primary Reference = Lampright, 1996.

General comments

Subject category Comment text
Deposit Model Name = Placer gold deposit (Cox and Singer, 1986; model 39a)
Deposit Other Comments = There are two different Portage Creeks in the Circle mining district, both of which flow away from the same divide. One creek flows south-southwest and has not yielded gold. The Portage Creek discussed for this site flows north-northeast into Medicine Lake.

Reporter information

Type Date Name Affiliation Comment
Reporter 09-SEP-1998 C.J. Freeman, J.R. Guidetti Schaefer, A.S. Clements Avalon Development Corporation