Mary L. Group

The Mary L. Group is a uranium mine located in Fremont county, Colorado at an elevation of 8,199 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: Mary L. Group
Secondary: Mary L. 1-6 Claims

Commodity

Primary: Uranium

Location

State: Colorado
County: Fremont
District: Tallahassee Creek

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

Owner Name: John T. Fontecchio, E.J. Smaller
Years: 1980 -

Production

Year: 1962
Time Period: 1955-1962
Mined: 2179.000 mt
Material type: Ore
Description: Cp_Grade: ^0.24% U308

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Surface-Underground
Year First Production: 1955
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

Model Name: Sandstone U

Orebody

Form: TABULAR, PODS, LENTICULAR BODIES

Structure

Type: R
Description: Thirty Nine Mile Volcanic Field, Currant Creek Basin

Type: L
Description: Echo Park Graben, Paleovalleys; North-South Trending Reverse Fault Places Precambrian Granite And Schist Against Tertiary Sandstones, Limiting Ore Body On East. Fault Strikes N 35-45 W, Dips 40 Ne; Numerous Small Faults And Fractures Increased Permeability Of Sediments

Alterations

Alteration Type: L
Alteration Text: Oxidation; Alteration Of Feldspar To Clay

Rocks

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

Name: Rhyolite
Role: Associated
Age Type: Host Rock Unit
Age Young: Eocene

Name: Rhyolite
Role: Associated
Age Type: Host Rock
Age Young: Eocene

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

Analytical Data

Analytical Data: DISEQUILIBRIUM RATIOS ON ORE SAMPLES GENERALLY FAVOR CHEMICAL U308

Materials

Ore: Uraninite
Ore: Torbernite
Ore: Coffinite
Gangue: Hematite
Gangue: Pyrite
Gangue: Calcite
Gangue: Limonite
Gangue: Gypsum

Comments

Comment (Development): DISCOVERED BY GROUND RADIOMETRIC ANOMALIES-NO OUTCROP PRESENT; DRILLING OUTLINED ORE BODY

Comment (Geology): DEPOSITS LOCALIZED AND PRESERVED BY SLUGGISH GROUNDWATER MOVEMENT IN AREA. THOSE CONDITIONS STILL PRESENT AS EVIDENCED BY ARTESIAN PRESSURE IN WELLS AND SPRINGS ISSUING FROM ECHO PARK FORMATION AND BY A PRESENT URANIUM CONTENT OF GROUNDWATER IN AREA AS HIGH AS 900 PPB.

Comment (Location): PROPERTY ADJOINS SMALLER AND JOAN MINES ; INFO FROM LAND.ST :1976

Comment (Location): Location based on USAEC 1955 preliminary recon. report.

Comment (Workings): OPEN PIT, UNDERGROUND WORKINGS OFF OF PIT WALLS

Comment (Deposit): THE DEPOSIT IS RELATIVELY FLAT-LYING WITH LOCAL THICKENING AND THINNING. THE UNDERLYING GRANITE IS MINERALIZED BUT DOES NOT CONTAIN KNOWN ORE. PART OF THE ORE BODY DESCRIBED ABOVE MAY HAVE BEEN MINED AS THE SMALLER AND JOAN 2 MINES, WHICH ADJOIN THIS PROPERTY

References

Reference (Deposit): EPIS, R.C., WOBUS, R.A. AND SCOTT, G.R., 1979, GEOLOGIC MAP OF THE BLACK MOUNTAIN QUADRANGLE, FREMONT AND PARK COUNTIES, COLORADO: USGS MAP I-1195, 1:62,500.

Reference (Deposit): DICKINSON, K.A., 1981, GEOLOGIC CONTROLS OF URANIUM MINERALIZATION IN THE TALLAHASSEE CREEK URANIUM DISTRICT, FREMONT COUNTY, COLORADO: THE MOUNTAIN GEOLOGIST, V. 18, NO. 4, P. 88-94.

Reference (Deposit): SIMON, M.R., 1956, URANIUM DEPOSITS OF CENTRAL AND SOUTH-CENTRAL COLORADO, IN GUIDEBOOK TO THE GEOLOGY OF THE RATON BASIN, COLORADO: ROCKY MOUNTAIN ASSOCIATION OF GEOLOGISTS GUIDEBOOK, P. 84.

Reference (Deposit): BABCOCK, J.A., 1980, TALLAHASSEE CREEK URANIUM DEPOSITS: DENVER REGIONAL EXPLORATION GEOLOGISTS SOCIETY GUIDEBOOK, P. 15-31.

Reference (Deposit): MACPHERSON, B.A., 1959, GEOLOGY AND URANIUM DEPOSITS OF THE TALLAHASSEE CREEK DISTRICT, FREMONT COUNTY, COLORADO: US ATOMIC ENERGY COMMISSION RME-1083, 39 P.

Reference (Production): NELSON-MOORE AND OTHERS, 1978

Reference (Deposit): NELSON-MOORE, J.L., COLLINS, D.B. AND HORNBAKER, A.L., 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: Colorado Geological Survey Bulletin 40,P. 150.

Colorado Mining Photos

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