Alexander Shaft

The Alexander Shaft is a silver mine located in Custer county, Colorado at an elevation of 9,131 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

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: Alexander Shaft

Commodity

Primary: Silver
Secondary: Copper

Location

State: Colorado
County: Custer
District: Rosita

Land Status

Land ownership: Federal
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

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Underground
Discovery Year: 1882
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

Model Name: Epithermal veins

Orebody

Not available

Structure

Type: R
Description: Rosita Crater And Cauldron Complex

Type: L
Description: North-Trending Fissures Dipping About 65 Degrees East

Alterations

Alteration Type: L
Alteration Text: Strong Argillization

Rocks

Name: Andesite
Role: Associated
Age Type: Host Rock
Age Young: Oligocene

Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Oligocene

Name: Andesite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Oligocene

Analytical Data

Not available

Materials

Ore: Covellite
Ore: Malachite
Gangue: Calcite
Gangue: Barite

Comments

Comment (Geology): THE ROSITA ANDESITE IS RELATIVELY FRESH HERE

Comment (Deposit): Discovery Year: 1870-1895

Comment (Location): NEAR INVINCIBLE SHAFT AND PRINGLE HILL ; INFO FROM LAND.ST :(1976)

Comment (Development): A SHAFT WAS SUNK TO AN UNKNOWN DEPTH

References

Reference (Deposit): SHARP, W.M., 1978, GEOLOGIC MAP OF THE SILVER CLIFF AND ROSITA VOLCANIC CENTERS, CUSTER COUNTY, COLORADO: USGS MAPS I-1081.

Reference (Deposit): CROSS, WHITMAN, 1896, GEOLOGY OF SILVER CLIFF AND THE ROSITA HILLS, COLORADO: USGS 17TH ANN. REPORT, PT 2, P. 263-403.

Colorado Mining Photos

Check out this collection of Colorado's best historic mining photos: Incredible Photos of Colorado Mining Scenes.