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Poorman Creek

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

Geologic information

Identification information

Deposit ID 10038123
MRDS ID M045408
Record type Site
Current site name Poorman Creek
Alternate or previous names Kast, Nelson and Larson
Related records 10282989

Geographic coordinates

Geographic coordinates: -150.81279, 62.58954 (WGS84)
Relative position Poorman Creek is a tributary to Cottonwood Creek, which in turn flows southwest into Peters Creek. The location of this placer is given by Mertie (1919, p. 257), as the confluence of Poorman and Dandy Creeks, where the paystreak was reported to be widest (150 feet). Placer claims extend at least one-half mile downstream from this location as shown by the U.S. Bureau of Mines (1998). Also shown as locality 29 in Clark and Cobb (1972) and locality 85 in Reed and others (1978).

Site location context

Political divisions (FIPS codes)

Matanuska-Susitna(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Talkeetna C-2(quadrangle 1:63,360 scale)

Talkeetna NE(quadrangle 1:100,000 scale)

Talkeetna(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Yentna River(hydrologic unit)

Susitna River(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Denali State Park(State Park)

State Park ST(Type of land area)

ST(Federal land areas administered by ST)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Copper Secondary
Platinum Critical Secondary
Tin Critical Secondary
Thorium Secondary
Uranium Secondary
Zirconium Critical Secondary

Materials information

Materials Type of material
Cassiterite Ore
Gold Ore
Ilmenite Ore
Iridium Ore
Magnetite Ore
Platinum Ore
Pyrite Ore
Iridosmine Ore

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) -150.81279, 62.58954
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Poorman Creek drains across the contact between Mesozoic slate and argillite (KJs) cut by Tertiary (?) soda rhyolites with associated quartz stringers and continentally derived Tertiary sedimentary rocks of the Kenai Group (Mertie, 1919; Reed and Nelson, 1980). The discovery claim is underlain by Mesozoic sedimentary rocks that strike N35E and dip 55NW (Mertie, 1919; Robinson and others, 1955; Reed and others, 1978).? Mining on Poorman Creek began at least as early as 1907 when six men recovered 1,329 ounces of gold (Garrett, 1998). Mertie (1919) reported that a bench deposit near the mouth of Dandy Creek, covered 2500 square feet and averaged 25 feet thick, or about 2300 cubic yards of gravel. ? Concentrates contain cassiterite, gold, ilmenite, iridium, iridoosmium, magnetite, platinum, pyrite, garnet, quartz, and zircon (Cobb and Reed, 1980). Grades of 0.09% U, 0.06% ThO2, 0.229% eU, and 0.22% Cu are reported from the concentrates (Mertie, 1919). The U.S. Geological Survey analyzed a sample of platinum metals weighing 41.6 grains, with specific gravity of 18.1, which contained 32% iridoosmium, 11% iridium, 1.4% rhodium, 47.3% platinum, trace palladium, and 8.3% other elements. Concentrates were reported to run 36.54% tin, equivalent to 46% cassiterite (Mertie, 1919; Robinson and others, 1955). According to Mertie (1919), gold and cassiterite were likely to have been derived from mineralized bedrock within the drainage. He also reported that Poorman Creek contained the most platinum of any placer in the Kahiltna valley. Clark and Hawley (1968) indicate that platinum-group minerals in the Yentna District may be derived from altered mafic or ultramafic dikes that cut the Mesozoic sedimentary rocks.? Also see Peters Creek (TL045).
  • Age = Pleistocene.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Mining district

District name Yentna

Comments on the production information

  • Production Notes = A bench deposit near the mouth of Dandy Creek mined in 1917 (Mertie, 1919) covered 2500 square feet and averaged 25 feet thick, or about 2300 cubic yards of gravel. Concentrate contained 0.09% U, 0.06% ThO2, 0.229% Eu, and 0.22% Cu. The U.S. Geological Survey analyzed a sample of platinum metals weighing 41.6 grains, with specific gravity of 18.1, which contained 32% iridosmium, 11% iridium, 1.4% rhodium, 47.3% platinum, trace palladium, and 8.3% other elements. Concentrates were reported to run 36.54% tin, equivalent to 46% cassiterite (Mertie, 1919; Robinson and others, 1955).

Comments on the workings information

  • Workings / Exploration = Garrett (1998) reports current placer mining by mechanical cut-and-fill techniques and feed hopper, trommel and sluice processing. Garrett (1998) reports current placer mining by mechanical cut-and-fill techniques and feed hopper, trommel and sluice processing. Exploration has been conducted by test drilling and pits. Hydraulic and hand-mining operations were conducted in the past.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Mertie, 1919

General comments

Subject category Comment text
Deposit Model Name = Placer Au-PGE (Cox and Singer, 1986; model 39a).
Deposit Other Comments = This placer ground is shown by C.C. Hawley and Associates, Inc. (1978) as part of the reserve area held by the Peters Creek Mining Corporation. See also Peters Creek (TL045).

Reporter information

Type Date Name Affiliation Comment
Reporter 10-AUG-1998 Madelyn A. Millholland Millholland & Associates

Beyond USGS

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

Maps centered on this site

Authoritative Alaska resources

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