Four Corners Mine

The Four Corners Mine is a uranium mine located in Jefferson county, Colorado at an elevation of 5,840 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: Four Corners Mine
Secondary: Pallaoro Lease
Secondary: Morrison Mine

Commodity

Primary: Uranium
Secondary: Vanadium
Tertiary: Molybdenum

Location

State: Colorado
County: Jefferson
District: Foothill 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: Unknown

Ownership

Not available

Production

Year: 1956
Description: Ap_Grade: ^0.23% U308
Year: 1955
Description: Ap_Grade: ^0.19% U308
Year: 1960
Time Period: 1955-1960
Description: Cp_Grade: ^0.19% U308

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1955
Year Last Production: 1960
Discovery Year: 1954
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

Form: WEDGE, LENTICULAR

Structure

Type: R
Description: Denver Basin, Front Range Uplift

Type: L
Description: Golden Fault, Damming Fault

Alterations

Not available

Rocks

Name: Sandstone
Role: Host
Age Type: Host Rock Unit
Age Young: Late Cretaceous

Name: Sandstone
Role: Host
Age Type: Host Rock
Age Young: Late Cretaceous

Analytical Data

Analytical Data: PRINCIPAL ORE GRADES RANGED FROM 0.19 TO 0.23% U308, OVERALL 0.19% U308

Materials

Ore: Uraninite
Gangue: Pyrite
Gangue: Ilsemannite

Comments

Comment (Production): NO PRODUCTION IN 1958 AND 1959. NELSON-MOORE AND OTHERS (1978) CITE V205 PRODUCTION. DISCREPANCY BETWEEN SOURCES AS TO TOTAL PRODUCTION; RICHTER'S FIGURES USED FOR ANNUALS, CUMUL. ORE, AND CUMUL. U308.

Comment (Deposit): URANINITE AND URANIFEROUS ASPHALT (PROBABLY RELATED TO OIL SEEPS IN AREA) COAT SAND GRAINS AND FILL INTERSTICES IN SANDSTONE AND TO SMALL EXTENT FILL FRACTURES IN DAMMING FAULT ZONE. SOME ORE IS SPHEROIDAL AND COMPOSED OF CONCENTRIC BANDS OF URANINITE AROUND PYRITE GRAIN. ORE BODIES ARE ELONGATED, THIN, DISCONTINUOUS WEDGES AND LENSES PARALLEL TO INTERSECTION OF DAMMING FAULT AND BEDDING. MOST MINED ORE CAME FROM HANGING WALL OF FAULT ALTHO SOME FOUND IN FOOTWALL. GOLDSTEIN (1957) BELIEVED URANIUM TO BE OF PRIMARY ORIGIN AND WAS PRECIPITATED FROM ASCENDING HYDROTHERMAL SOLUTIONS ALONG DAMMING FAULT AT ZONES OF FAVORABLE SANDSTONE PERMEABILITY.

Comment (Workings): 75-FT VERTICAL SHAFT WITH LEVELS AT 62 AND 75 FT. DRIFTS ON 75-FT LEVEL EXTEND ABOUT 200 FT TO NW AND ABOUT 100 FT TO SE

Comment (Location): ON NORTH SIDE OF TURKEY CREEK AT BOTTOM OF DAKOTA HOGBACK, JUST ACROSS CREEK FROM MANN RANCH MINE ; INFO FROM LAND.ST :(1976)

References

Reference (Production): RICHTER, 1964, P. 102-103; NELSON-MOORE AND OTHERS (1978), P. 194

Reference (Deposit): SCOTT, G.R., 1972, GEOLOGIC MAP OF THE MORRISON QUADRANGLE, JEFFERSON COUNTY, COLORADO: USGS MAP I-790-A

Reference (Deposit): RICHTER, D.H., 1964, FOUR CORNERS URANIUM MINE, IN SIMS, P.K., AND SHERIDAN, D.M., GEOLOGY OF URANIUM DEPOSITS IN FRONT RANGE, COLORADO: USGS BULL. 1159, P. 102-103, PL. 5.

Reference (Deposit): GOLDSTEIN, E.H., 1957, GEOLOGY OF THE DAKOTA FORMATION URANINITE DEPOSIT NEAR MORRISON, COLORADO: ECON. GEOLOGY, V. 52, NO. 7, P. 775-785

Reference (Deposit): NELSON-MOORE, J.L., AND OTHERS, 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: CGS BULL. 40, P. 194

Colorado Mining Photos

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