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Portage Creek

Producer in Alaska, United States with commodities Gold, Bismuth, Copper, Tin, Uranium, Tungsten, Zinc
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Mineral occurrence model information
  7. Nearby scientific data
  8. Economic information about the deposit and operations
  9. Mining district
  10. Links to other databases
  11. Bibliographic references
  12. General comments
  13. Reporter information

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.

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Circle B-2(quadrangle 1:63,360 scale)

Circle SE(quadrangle 1:100,000 scale)

Circle(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

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

Mineral occurrence model information

Model code 119
USGS model code 39a
Deposit model name Placer Au-PGE
Mark3 model number 54

Nearby scientific data

(1) -144.61591, 65.46174
ListMap

Economic information

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 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

Bibliographic references

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

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.