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Arch

Prospect in Alaska, United States with commodity Gold
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Geologic information

Identification information

Deposit ID 10000953
MRDS ID A011623
Record type Site
Current site name Arch
Alternate or previous names Fern, Taulman & Goodell, Sidney Ridge property
Related records 10136594

Geographic coordinates

Geographic coordinates: -149.23657, 61.8065 (WGS84)
Relative position On the south side of Archangel Creek. Marked with adit symbol and labeled 'Arch Prospect' on the Anchorage D-6 1:63,360-scale topographic map. Accurate within 400 ft. Locality 21 of Cobb (1972) and locality 17 of MacKevett and Holloway (1977).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary

Comments on the commodity information

  • Ore Material = minor sulfides
  • Ore Material = minor sulfides

Materials information

Materials Type of material
Gold Ore
Quartz Gangue

Alteration

  • (Local) Wall-rock alteration within a few inches of the veins is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954).

Mineral occurrence model information

Model code 273
USGS model code 36a
Deposit model name Low-sulfide Au-quartz vein
Mark3 model number 27

Nearby scientific data

(1) -149.23657, 61.8065
ListMap

Comments on the geologic information

  • Geologic Description = Quartz vein 12 to 20 inches thick occurs in a gouge zone which cuts the Late Cretaceous Willow Creek Pluton. The overall thickness of the quartz and gouge measures as much as 40 inches. The quartz, as seen in the dump, is banded and consists of interlocking quartz crystals surrounding pieces of altered country rock. Minor sulfide minerals present. Assays show about 1.45 oz/ton Au (Capps, 1915). ? the Willow Creek Pluton is a zoned pluton: the outer part consists of hornblende quartz diorite and lesser hornblende tonalite; the core consists of hornblende-biotite granodiorite, and lesser hornblende-biotite quartz monzodiorite and biotite quartz monzonite. Wall-rock alteration within a few inches of the veins is intense, but seldom extends more than 10 to 12 inches beyond the quartz filling. Sericitization and carbonate alteration predominate, but there is some pyritization and in the outer parts of the alteration zone chloritization is present (Ray, 1954).
  • Age = Late Cretaceous or younger; vein cuts the Late Cretaceous Willow Creek Pluton.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Willow Creek

Comments on the production information

  • Production Notes = Unknown production.

Comments on the workings information

  • Workings / Exploration = Developed by two adits and some drifts of which the total length is unknown. Assays show about 1.45 oz/ton Au; reported as $32/ton Au, with Au at $20.67 per fine oz in 1915 (Capps, 1915). Two small hydropowered mills were being planned in the summer of 1914. Stoll (1997) indicated that the mills were never delivered, possibly due to the onset of WWI. By 1919, the old workings had mostly caved. Sampling conducted in the mid-1940's turned up promising gold values, hinting that the prospect was a 'sleeper' (Stoll and McDonald, 1946). In 1984, miners were reopening a caved area to access old stopes which reportedly still contained ore.? In 1984, the U.S. Bureau of Mines collected a 100 pound bulk sample from the surface ore dump. The +1/2 inch fraction contained 0.013 oz/ton Au and 0.2 oz/ton Ag; the -1/2 inch fraction contained 0.03 oz/ton Au and 0.003 oz/ton Ag (Kurtak, 1986).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A011623
USGS Alaska Resource Data File ARDF AN046

Bibliographic references

  • Deposit

    Capps, S.R., 1914, Gold lodes and placers of the Willow Creek district: U.S. Geological Survey Bulletin 592, p. 245-272.

  • Deposit

    Capps, S.R., 1915, The Willow Creek District, Alaska: U.S. Geological Survey Bulletin 607, 86 p.

  • Deposit

    Stoll, W.M. and McDonald, J.M., 1946, Field notes of a survey of gold prospects in the eastern Willow Creek district, Alaska: W.M. and J.A. Stoll collection, Archives and Manuscripts department, University of Alaska, Anchorage, Alaska.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.

  • Deposit

    Kurtak, J.M., 1986, Results of the 1984 Bureau of Mines site specific field studies within the Willow Creek mining district: U.S. Bureau of Mines Open-File Report 17-86, 17 p.

  • Deposit

    Stoll, W.M., 1997, Hunting for gold in Alaska's Talkeetna Mountains 1897-1951: Greensburg, Pennsylvania, Henry Printing, 301 p.

  • Deposit

    Cobb, E.H., 1979, Summary of references to mineral occurrences (other than mineral fuels and construction materials in the Anchorage quadrangle, Alaska: U.S. Geological Survey Open-File Report 79-1095, 184 p.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous mineral deposits in the western part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-F, 38 p., 1 sheet, scale 1:1,000,000.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Anchorage quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-409, 1 sheet, scale 1:250,000.

  • Deposit

    Capps, S.R., 1916, Gold mining in the Willow Creek district: U.S. Geological Survey Bulletin 642-G, p. 147-194, 195-200.

  • Deposit

    Capps, S.R., 1919, Gold lode mining in the Willow Creek district: U.S. Geological Survey Bulletin 692-D, p. 177-186.

  • Deposit

    Capps, S.R., 1916, Gold mining in the Willow Creek district: U.S. Geological Survey Bulletin 642-E, p. 147-200.

Comments on the references

  • Primary Reference = Capps, 1915

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Reporter information

Type Date Name Affiliation Comment
Reporter 30-JUL-1998 D.P. Bickerstaff U.S. Geological Survey
Reporter 30-JUL-1998 S.W. Huss U.S. Geological Survey