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Scrafford

Past Producer in Alaska, United States with commodities Antimony, Silver, Gold, Lead
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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. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10002884
MRDS ID A015370
Record type Site
Current site name Scrafford

Geographic coordinates

Geographic coordinates: -147.7599, 64.99856 (WGS84)
Relative position The Scrafford mine is located in the SE1/4 sec. 16, T. 2 N., R. 1 W., Fairbanks Meridian. This mine is accessible from the Elliott Highway and Old Murphy Dome Road. Approximately 4 miles down Old Murphy Dome Road, a steep, rough road leads 0.5 mile north to the Scrafford mine. The mine is just north of the southeast fork of Eagle Creek, a tributary of Treasure Creek.

Site location context

Political divisions (FIPS codes)

Fairbanks North Star(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Fairbanks D-2(quadrangle 1:63,360 scale)

Big Delta NW(quadrangle 1:100,000 scale)

Fairbanks(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Antimony Critical Primary
Silver Secondary
Gold Secondary
Lead Secondary

Materials information

Materials Type of material
Galena Ore
Gold Ore
Stibnite Ore

Alteration

  • (Local) The footwall rocks of the deposit are highly oxidized and contain stibiconite and scorodite (Robinson and Bundtzen, 1982, p. 5). The main shear is filled with black graphitic gouge, bright-orange iron-stained clay, and white clay that supports clasts of schist, stibnite, and stibnite oxidation products (Dashevsky, 1993). Strong clay and sericite alteration is confined to gouge zones within the shear. The schist footwall is silicified and quartz veined (Dashevsky, 1993).

Mineral occurrence model information

Model code 180
USGS model code 27d
Deposit model name Simple Sb (veins, pods, etc)

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite
  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite

Nearby scientific data

(1) -147.7599, 64.99856
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The Scrafford mine is the largest producer of antimony ore in the Fairbanks mining district; production has been estimated at more than 2,700 tons of ore (Robinson and Bundtzen, 1982). Mining from open cuts took place from 1915 to 1916, in 1926, and from 1968 to 1970 (Cobb, 1976 [OFR 76-662, p. 169-170]). The deposit consists of massive stibnite localized along shear zones associated with stockwork-type quartz veinlets containing disseminated arsenopyrite and stibnite. The stibnite occurs in fibrous and columnar twinned crystals and as fine-grained massive aggregrates (Robinson and Bundtzen, 1982). In 1916, an assay of mineralized rock showed an average grade of $4 in gold (about 0.19 ounce of gold per ton) and 8 ounces of silver per ton (Brooks, 1916 [B 649, p. 29]). Most of the antimony ore that was produced had grades of 56 to 60 percent antimony; ore mined in 1970 and 1971 had a lower grade of 12 to 16 percent antimony (Robinson and Bundtzen, 1982, p. 3).? In 1982, Robinson and Bundtzen (1982) spent three days mapping and sampling several trenches on the Scrafford property and the following is a summary of their findings. Rocks in the trenches include quartz-mica schist, micaceous quartz schist, calc-schist, feldspathic schist, felsic tuff, and graphitic schist. Several felsic dikes are also present. The center of antimony-gold mineralization occurs along an east-west-trending shear zone that separates a barren hanging-wall sequence of quartz-muscovite schist, micaceous quartzite, and quartz-feldspar schist from a mineralized footwall sequence of feldspathic, micaceous quartzite and minor quartz-mica schist. The footwall rocks are highly oxidized, sheared, and cut by anastomosing quartz-sulfide veinlets. The shear zone in the main open cut is exposed for at least 320 feet; it strikes N. 80-85 E and dips 55-60 S. The stibnite-bearing vein in the shear pinches and swells from a width of 4 to 19 feet and is confined to the footwall side of the shear zone. The shear zone ranges from 6 to 38 feet wide. The hanging wall of the shear zone is dominated by incompetent quartz-mica schist, and the footwall is locally mineralized feldspathic quartzite (metatuff). The footwall quartzite is competent and highly fractured; the result is a favorable site for ore deposition.? In 1991-93, American Copper and Nickel Company drilled three reverse-circulation holes to investigate gold mineralization within the shear zone and in the silicified footwall schist (Dashevsky, 1993). The 1992 core hole was 330 feet deep. Nineteen feet assayed 0.107 ounce of gold per ton; five feet in the Scrafford shear zone assayed 0.026 ounce of gold per ton; and 14 feet in the silicified footwall assayed 0.136 ounce of gold per ton. The drilling program indicated that the footwall mineralization is confined within a narrow, sub-parallel zone beneath the Scrafford shear, and was probably not a viable bulk-minable target (Dashevsky, 1993).

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Fairbanks

Comments on the production information

  • Production Notes = Mining from open cuts took place from 1915 to 1916, in 1926, and from 1968 to 1970 (Cobb, 1976 [OFR 76-662, p. 169-170]). Production has been estimated at over 2,700 tons of ore, much of it from ore that ran 50 to 60 percent antimony (Robinson and Bundtzen, 1982).

Comments on the workings information

  • Workings / Exploration = Mining from open cuts took place from 1915 to 1916, in 1926, and from 1968 to 1970 (Cobb, 1976 [OFR 76-662, p. 169-170]). The shear-zone system in the main opencut is exposed for at least 320 feet (Robinson and Bundtzen, 1982). In 1982, Robinson and Bundtzen (1982) spent 3 days mapping and sampling several trenches on the Scrafford property. In 1991-93, American Copper and Nickel Company conducted soil sampling and drilled three reverse-circulation holes, totalling 1295 feet, to pursue the gold potential that was reported by Robinson and Bundtzen (Dashevsky, 1993).

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Robinson and Bundtzen, 1982

General comments

Subject category Comment text
Deposit Model Name = Simple Sb deposit (Cox and Singer, 1986; model 27d)

Reporter information

Type Date Name Affiliation Comment
Reporter 31-JUL-2001 J.R. Guidetti Schaefer Avalon Development Corporation
Reporter 31-JUL-2001 C.J. Freeman 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.