Hot Air Bench (Columbia Mine)

The Hot Air Bench (Columbia Mine) is a gold 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

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Site Name

Primary: Hot Air Bench (Columbia Mine)

Commodity

Primary: Gold
Secondary: Silver

Location

State: Alaska
District: Nome

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: Placer Au-PGE

Orebody

Not available

Structure

Not available

Alterations

Not available

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Arsenopyrite
Ore: Gold

Comments

Comment (Deposit): Model Name = Alluvial placer Au; elevated bench formed on ancestral Glacier Creek (Cox and Singer, 1986; model 39a).

Comment (Geology): Geologic Description = The Hot Air Bench appears to be a true bench of Glacier Creek. It is approximately 100 feet vertically above and 900 feet horizontally north of Glacier Creek. Two claims of the Hot Air Mining Company were located May 28, 1899, and August 17, 1900; the claims were patented in 1902 (U.S. Mineral Survey No. 403). Apparently the bench channel was very well defined for about 400 to 500 feet. According to Collier and others (1908, p. 193-194), who were in the area in 1903, the channel was about 100 feet wide and had well-defined bedrock rims. The channel gravels were at a depth of about 20 feet. Pay gravels, largely of schist and marble, were about 4 to 5 feet thick and rested on chloritic schist bedrock. Gold was described as similar to that in Glacier Creek (NM220): fine, bright, and well rounded. The well-defined channel apparently played out to the west and turned toward Glacier Creek to the east. Moffit (1913, p. 85-86) reported veins as much as 6 inches thick in bedrock below the channel in the direction of Snow Gulch. He proposed that the source of the placer gold was local. Cathcart (1922, p. 243), in contrast, did not believe the gold was local, a conclusion that appears borne out by the character of the gold reported by Collier and others (1908). Cathcart (1922) also reported that the schist contained arsenopyrite.? the Hot Air Bench was extremely rich. Historic photographs show rows of gold bars cast from Hot Air gold. Collier and others (1908) reported that the production was 'not less than$600,000' (about 30,000 ounces of gold) and that pay in the best part of the channel ran about 2.5 ounces of gold per cubic yard. Assuming the fairly common 900 fineness value of placer gold in this area, the placer also produced about 3,000 ounces of silver. Collier and others (1908) also reported that placer gold was found higher on the slopes, a report consistent with the later discovery of the Ullrich placer (NM218) above and upstream of Hot Air Bench.

Comment (Reference): Primary Reference = Collier and others, 1908

Comment (Geology): Age = Pleistocene.

Comment (Exploration): Status = Inactive

Comment (Production): Production Notes = Total production is believed to have been at least 600,000 dollars (gold at 20.67 dollars per ounce) or about 30,000 ounces of gold and 3,000 ounces of silver.

Comment (Workings): Workings / Exploration = The first bench claims were located in 1899; mining commenced immediately. The claims were surveyed for patent in 1901, at which time there was a small open cut on the Columbia claim. The richest part of the placer was mined by 1903, when the area was visited by Collier and others (1908). The deposit was mainly mined hydraulically; gold was recovered in a narrow sluice set in the downstream section towards Glacier Creek.

References

Reference (Deposit): Cathcart, S.H., 1922, Metalliferous lodes in southern Seward Peninsula: U.S. Geological Survey Bulletin 722, p. 163-261.

Reference (Deposit): Moffit, F.H., 1913, Geology of the Nome and Grand Central quadrangles, Alaska: U.S. Geological Survey Bulletin 533, 140 p.

Reference (Deposit): Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Nome quadrangle, Alaska: U.S. Geological Survey Open-File report 78-93, 213 p.

Reference (Deposit): Collier, A. J., Hess, F.L., Smith, P.S., and Brooks, A.H., 1908, The gold placers of parts of Seward Peninsula, Alaska, including the Nome, Council, Kougarok, Port Clarence, and Goodhope precincts: U.S. Geological Survey Bulletin 328, 343 p.

Reference (Deposit): Hummel, C.L., 1962, Preliminary geologic map of the Nome C-1 quadrangle, Seward Peninsula, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-247, 1 sheet, scale 1:63,360.

Reference (Deposit): Cobb, E.H., 1972, Metallic mineral resources map of the Nome quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-463, 2 sheets, scale 1:250,000.

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