Scrafford

The Scrafford is a antimony mine located in Alaska.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Scrafford

Commodity

Primary: Antimony
Secondary: Lead
Secondary: Gold
Secondary: Silver

Location

State: Alaska
District: Fairbanks

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Years of Production:
Organization:
Significant:

Physiography

Not available

Mineral Deposit Model

Model Name: Simple Sb (veins, pods, etc)

Orebody

Not available

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: 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).

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Galena
Ore: Gold
Ore: Stibnite

Comments

Comment (Production): 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).

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

Comment (Reference): Primary Reference = Robinson and Bundtzen, 1982

Comment (Workings): 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).

Comment (Exploration): Status = Inactive

Comment (Geology): 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).

References

Reference (Deposit): Hill, J.M., 1933, Lode deposits of the Fairbanks District, Alaska: U.S. Geological Survey Bulletin 849-B, p. 29-163.

Reference (Deposit): Killeen, P.L., and Mertie, J.B., 1951, Antimony ore in the Fairbanks District, Alaska: U.S. Geological Survey Open-File Report 51-46, 43 p.

Reference (Deposit): Robinson, M.S., and Bundtzen, T. K., 1982, Geology of the Scrafford antimony-gold lode deposit, Fairbanks mining district, Alaska: Alaska Division of Geological and Geophysical Surveys Open-File Report 173, 7 p., 1 sheet, scale 1:120.

Reference (Deposit): Chapin, Theodore, 1919, Mining in the Fairbanks district: U.S. Geological Survey Bulletin 692-F, p. 321-327.

Reference (Deposit): Brooks, A.H., 1916, Antimony deposits of Alaska: U.S. Geological Survey Bulletin 649, 67 p.

Reference (Deposit): Chapin, Theodore, 1914, Placer mining in the Yukon-Tanana region: U.S. Geological Survey Bulletin 592-J, p. 357-362.

Reference (Deposit): Dashevsky, S.S., 1993, Eagle Creek project (Au), Fairbanks district, Alaska: American Copper and Nickel Company, Inc., 60 p. (Report held by Sam Dashevsky, Northern Associates Inc., Fairbanks, Alaska; can be examined with permission from current lease holders).

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.