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Fern

Past Producer in Alaska, United States with commodities Gold, Lead, Tellurium, Tungsten
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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. Alteration
  8. Mineral occurrence model information
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10308765
MRDS ID A011619
Record type Site
Current site name Fern
Alternate or previous names Fern Gold Mining Co., Fern Gold Leasing Co., Fern & Goodell, Bartholf-Isaacs, Marmot
Related records 10000948, 10185322

Geographic coordinates

Geographic coordinates: -149.24369, 61.82456 (WGS84)
Relative position Marked with adit symbol and labeled 'Fern Mine' on the Anchorage D-6 1:63,360-scale topographic map, at headwaters of Archangel Creek. Accurate within 400 ft. This is locality 19 of Cobb (1972) and locality 16 of MacKevett and Holloway (1977).

Site location context

Political divisions (FIPS codes)

Matanuska-Susitna(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Anchorage D-6(quadrangle 1:63,360 scale)

Anchorage NW(quadrangle 1:100,000 scale)

Anchorage(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Susitna River(hydrologic unit)

Susitna River(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

BLM(Federal land areas administered by BLM)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Lead Secondary
Tellurium Critical Secondary
Tungsten Critical Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Galena Ore
Gold Ore
Nagyagite Ore
Pyrite Ore
Scheelite Ore
Tetrahedrite Ore
Ankerite Gangue
Quartz Gangue

Alteration

  • Wall rock has been intensely altered with ankerite, kaolinite, and secondary quartz (Ray, 1933). 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 (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) -149.24369, 61.82456
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = Quartz veins and stringers in shear zone cutting comminuted and kaolinized tonalite of the Late Cretaceous Willow Creek Pluton, 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. The main vein is as wide as 18 ft and is made up of quartz, gouge, and altered tonalite (Ray, 1954). Ore concentrated at intersections of main vein and smaller cross veins. The stringer veins are displaced and broken up into distinct blocks by major post-minerization faults. 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 (Ray, 1954). The wall rock has been intensely altered with ankerite, kaolinite, and secondary quartz (Ray, 1933). Metallic minerals include pyrite, arsenopyrite, tetrahedrite, galena, nagyagite, gold, and sparse scheelite (Ray, 1933). Assay of channel samples indicate a 12 ft sample of quartz stringers in altered country rock has 1.0 oz/ton Au, 8 to 12 inches of massive quartz yielded 0.45 oz/ton Au, and 2.5 ft zone of quartz and altered country rock show 2.3 oz/ton Au (Ray, 1933).
  • Age = Late Cretaceous or younger; veins cut the Late Cretaceous Willow Creek Pluton.

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Willow Creek

Comments on the production information

  • Production Notes = The Fern mine, under McDougal (1931-1941), had an estimated production worth over $1,000,000 (Ray, 1954). Stoll (1997) estimates that from the Fern Gold Mining Company's first gold shipments, in 1922, into 1950 under Dodson, the Fern vein yielded roughly 44,000 ounces of gold. In aggregate gold recovery, the Fern lode is the district's fourth most important, after Lucky Shot-War Baby (ARDF numbers AN002 and AN003), Independence (ARDF number AN001), and Gold Bullion (ARDF number AN004).

Comments on the workings information

  • Workings / Exploration = An adit was driven 40 ft to vein and then 56 ft along vein in attempt to find the ore shoot exposed at surface (Capps, 1919). By 1920, the adit was driven 300 ft (Chapin, 1920). A mill was installed, and both mine and mill operated in 1922 (Brooks and Capps, 1924). The first gold from the mine was produced in 1922. The Fern Gold Mining Company milled its last ore in 1928. Explored by more than 4,000 ft of underground workings plus stopes on 2 levels by 1931 (Ray, 1933). Workings extended beneath a tunnel of the adjoining Talkeetna mine (ARDF number AN025), but do not connect. In 1931, Thomas McDougal leased the property and worked the mine as the Fern Gold Leasing Company (Stoll, 1997). Mining stopped in 1941 and McDougal gave up the lease in 1945. During the time from 1931 to 1941, two new levels of adits were driven with over 3,000 ft aggregate length. In 1945, A.G. Dodson obtained a lease for the property and operated the mine until his death in late 1950. A mill and cyanide plant were present on the property, however the mill was destroyed by fire in 1946. A new mill was completed in 1948. Assay of channel samples indicate a 12 ft sample of quartz stringers in altered country rock has 1.0 oz/ton Au, 8 to 12 inches of massive quartz yielded 0.45 oz/ton Au, and 2.5 ft zone of quartz and altered country rock show 2.3 oz/ton Au (Ray, 1933).

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Ray, 1954

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Deposit Other Comments = Marmot and Bartholf-Isaacs prospects probably all became part of Fern property. Capps (1915) reports assessment work at Bartholf-Issacs prospect in 1914 and Chapin (1921) reports work during the winter of 1919-1920 at Marmot prospect. This is the last references to these two prospects in the literature.

Reporter information

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

Beyond USGS

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

External references

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.