Old Man Breccia

The Old Man Breccia is a gold and copper 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: Old Man Breccia

Commodity

Primary: Gold
Primary: Copper
Secondary: Iron

Location

State: Alaska
District: Yentna

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

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

Physiography

Not available

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Iron-oxide

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Chalcopyrite
Ore: Gold
Ore: Pyrite
Ore: Pyrrhotite
Gangue: Quartz

Comments

Comment (Exploration): Status = Inactive

Comment (Workings): Workings / Exploration = Exploration work included mapping, rock chip geochemistry, grid soil sampling, grid magnetic and VLF geophysical surveys, and diamond drilling. ??

Comment (Reference): Primary Reference = Reed and Elliott, 1970

Comment (Geology): Geologic Description = A float sample of pyrrhotite-chalcopyrite-quartz-pyrite, that contained several ounces of gold, lead to the discovery of a breccia in siltstone, part of Upper Jurassic and Lower Cretaceous flysch (KJs) of the Kahiltna terrane. The breccia is exposed over an area approximately 105 feet x 90 feet. Within the breccia angular clasts of argillite from less than one inch up to a few inches long occur in a matrix of well-healed milky quartz and lesser carbonate. The quartz-argillite breccia forms sinuous, sub-vertical zones around large argillite blocks. Sulfides in breccia are sparse (generally less than 1% total) and consist of pyrrhotite pods +/- pyrite and chalcopyrite, and rare coarse-grained arsenopyrite. Veins of quartz-pyrrhotite-pyrite-chalcopyrite crosscut the breccia zone and vary from a few inches to 2 feet in thickness and contain occasional specks of visible gold. No obvious alteration occurs in the hanging wall (Cominco American Incorporated, unpublished reports,1986-1988).

Comment (Deposit): Model Name = Gold-bearing, sulfide breccia

Comment (Commodity): Gangue = Carbonate

References

Reference (Deposit): Reed, B.L., and Elliot, R.L., 1970, Reconnaissance geologic map, analyses of bedrock and stream sediment samples, and an aeromagnetic map of parts of the southern Alaska Range: U.S. Geological Survey Open-file Report 70-271, 24 p., 4 plates, scale 1:250,000.

Reference (Deposit): Reed, B.L., and Elliott, R.L., 1970, Reconnaissance geologic map, analyses of bedrock and stream sediment samples, and an aeromagnetic map of parts of the southern Alaska Range: U.S. Geological Survey Open-file Report 70-271, 24 p., 4 sheets, scale 1:250,000.

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.