Freeport Tunnel

The Freeport Tunnel is a silver mine located in Mineral county, Colorado at an elevation of 10,151 feet.

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: Freeport Tunnel

Commodity

Primary: Silver

Location

State: Colorado
County: Mineral
District: Creede District

Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Not available

Workings

Type: Underground

Ownership

Owner Name: Minerals Engineering Co. (Meco) And Homestake Mining Co.
Home Office: Grand Junction, Co.
Years: 1981 -

Owner Name: Minerals Engineering Co. (Meco)
Home Office: Grand Junction, Co.
Years: 1981 -

Production

Not available

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Discovery Year: 1919
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Type: R
Description: San Juan Volcanic Field; La Garita, Creede, And Bachelor Calderas

Type: L
Description: Amethyst Fault, Bachelor Mtn. Paleovalley (Controlled By Creede Graben)

Alterations

Alteration Type: L
Alteration Text: Silicification

Rocks

Name: Quartz Latite
Role: Associated
Age Type: Associated Rock
Age Young: Oligocene

Name: Quartz Latite
Role: Associated
Age Type: Host Rock
Age Young: Oligocene

Name: Quartz Latite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Oligocene

Analytical Data

Analytical Data: G.T. 3 OZ/TON AG

Materials

Ore: Acanthite
Gangue: Limonite
Gangue: Jarosite
Gangue: Barite
Gangue: Hematite

Comments

Comment (Development): RICH ORES ASSAYING AS HIGH AS 800 OZ/TON AG WERE MINED AND QUICKLY DEPLETED FOLLOWING 1919 DISCOVERY. NO PROSPECTING UNTIL 1975 UNDER MECO-FREEPORT JOINT VENTURE; 1981 FEASIBILITY STUDY INDICATES PROVEN AND PROBABLE RESERVES OF 3.348 MILLION TONS OF ORE AT 6.39 OZ/TON AG. EXPLORATION AND EVALUATION CONTINUING.

Comment (Workings): ONE TUNNEL DRIVEN WESTERLY 680 FT

Comment (Location): S-T-R, LAT-LONG, AND ELEV DETERMINED FROM EMMONS AND LARSEN'S (1923) TOPO MAP (1:24,000). MINE OR CLAIM LIES ON SE SIDE OF BACHELOR MTN. SW OF BACHELOR AND COMMODORE MINES. ; INFO FROM LAND.ST :(1976)

Comment (Deposit): AG SULFIDES WITH TRACE OF BASE METALS ARE VERY FINELY DISSEMINATED IN 1) CARBONACEOUS, TUFFACEOUS, SILTY TO COARSE-GRAINED SANDSTONE IN LOWER MONKEMEYER SS., AND 2) IN SANDY MATRIX OF COMMODORE CONGLOMERATE AND ASSOCIATED WITH FE AND MN OXIDE ALTERATION OCCURRING AS FRACTURE AND PORE SPACE COATINGS. MINERALIZATION FOUND BOTH IN SILICIFIED AND NONSILICIFIED ROCK.

References

Reference (Deposit): EMMONS, W.H., AND LARSEN, E.S. 1923, GEOLOGY AND ORE DEPOSITS OF THE CREEDE DISTRICT, COLORADO: USGS BULL. 718, 198 P.

Reference (Deposit): STEVEN, T.A., AND RATTE, J.C., 1965, GEOLOGY AND STRUCTURAL CONTROL OF ORE DEPOSITION IN THE CREEDE DISTRICT, SAN JUAN MOUNTAINS, COLORADO: USGS PROF. PAPER 487, 90 P.

Reference (Deposit): LINDEMANN, J.W., AND OTHERS, EDS., 1981, FIELD TRIP NOTES, CREEDE MINING DISTRICT, SAN JUAN VOLCANIC PROVINCE, COLORADO: DENVER REGIONAL EXPLORATION GEOLOGISTS SOC. GUIDEBOOK

Colorado Mining Photos

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