Thornburg Mine

The Thornburg Mine is a uranium mine located in Saguache county, Colorado at an elevation of 8,661 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: Thornburg Mine
Secondary: Los Ochos Mine, Thornburg No. 1 Mine, T-1 Mine
Secondary: Los Ochos Claims

Commodity

Primary: Uranium

Location

State: Colorado
County: Saguache
District: Cochetopa (Cochetopa Creek) District

Land Status

Land ownership: BLM Administrative Area
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: Gunnison Mining Co.
Years: 1962 -

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1954
Year Last Production: 1962
Discovery Year: 1954
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; Gunnison Uplift

Type: L
Description: Cochetopa Dome; Los Ochos Fault; Razor Creek Dome

Alterations

Alteration Type: L
Alteration Text: Kaolinitization, Sericitization, Chloritization, Hematite Staining

Rocks

Name: Quartz Monzonite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic

Name: Quartz Monzonite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Neoproterozoic

Analytical Data

Analytical Data: ON LOS OCHO NO. 1, BACKGROUND RADIATION 0.03 MR/HR, MAXIMUM 0.5 MR/HR, ON LOS OCHO NO. 2, BACKGROUND RADIATION 0.3 MR/HR. MAXIMUM 1.0 MR/HR. SPECTROGRAPHIC ANALYSES AND CALCULATED DEFICIENCY RATIOS SHOW RELATIVE ABUNDANCE OF MO, PB, AND CU COMPARED TO COLORADO PLATEAU ORES, SIMILAR ABUNDANCE OF CO AND NI, BUT DEFICIENCY IN V AND AS.

Materials

Ore: Zippeite
Ore: Pitchblende
Ore: Uranophane
Gangue: Chalcedony
Gangue: Marcasite
Gangue: Barite

Comments

Comment (Workings): TUNNEL FROM MAIN ADIT DRIVEN S 80 W APPROX. ALONG FAULT FOR 600 FT. SECOND PORTAL (KNOWN AS T-2 MINE), LOCATED 240 FT S 69 W FROM MAIN PORTAL, DRIVEN 240 FT ON 21-DEGREE DECLINE; TUNNEL THEN PROCEEDS APPROX. 370 FT GENERALLY WESTWARD, THENCE APPROX. 550 FT GENERALLY S 75 W. CROSSCUT CONNECTS BOTH TUNNELS AT BOTTOM OF DECLINE. AT BEND IN SECOND TUNNEL, SEVERAL RAISES DRIVEN TO 34-FT AND 84-FT SUBLEVELS HAVING DRIFTS OF 175 FT AND 40 FT, RESPECTIVELY. OTHER RAISES, WINZES, AND CROSSCUTS TOTAL APPROX. 525 FT

Comment (Location): ON PROMINENT KNOLL EAST OF UNNAMED TRIBUTARY OF COCHETOPA CREEK ; INFO FROM LAND.ST :1976

Comment (Commodity): PITCHBLENDE IS PRIMARY U MINERAL OCCURRING IN VEINLETS AND AS COATING ON MARCASITE GRAINS. AUTUNITE AND URANOPHANE ARE SECONDARY MINERALS. URANOPILITE, ZIPPEITE, AND JOHANNITE FORMED AS ENCRUSTATIONS AFTER EXPOSURE IN MINE WORKINGS

Comment (Production): PRODUCTION RECORD INCLUDES FIGURES FOR THORNBURG (T-1 AND WEST MINES), THORNBURG INCLINE (T-2), AND EAST MINE (KATHY JO AND IRISHMAN'S DREAM CLAIMS). TOTAL PRODUCTION FOR 1959-62 BROKEN OUT AS FOLLOWS: 1959, 6790 ST FOR T-2, 91441 ST FOR T-1 AND WEST, 495 ST FOR EAST; 1960, 14487 ST FOR T-2, 113217 ST FOR T-1 AND WEST, 8193 ST FOR EAST; 1961, 21692 ST FOR T-2, 121599 ST FOR T-1, 15632 ST FOR EAST; 1962, 2192 ST FOR T-2, 9690 ST FOR T-1, 1546 ST FOR EAST

Comment (Development): DISTRICT MINED PREVIOUSLY FOR AU AND BASE METALS. GUNNISON MINING CO. DISCOVERED URANIUM IN 1954 ALONG LOS OCHOS FAULT.

Comment (Deposit): MINERALIZATION ASSOCIATED WITH LOS OCHOS FAULT, WHICH DISPLACES MORRISON FM SANDSTONE AND MUDSTONE AGAINST PRECAMBRIAN SCHIST. INITIAL FAULT DISPLACEMENT WAS FOLLOWED BY SILICIFICATION OF SEDIMENTARY ROCKS ALONG FAULT; THEN RENEWED MOVEMENT WITH FRACTURING AND BRECCIATION OF SILICIFIED ROCKS; THEN INTRODUCTION OF MARCASITE AND PITCHBLENDE. FINE-GRAINED PITCHBLENDE OF HYPOGENE ORIGIN OCCURS IN VEINLETS WITH MARCASITE AND CLAY MINERALS, AS FINELY DISSEMINATED GRAINS IN FRACTURES AND QUARTZ GANGUE, AND AS COATINGS ON MARCASTIE GRAINS. SECONDARY URANIUM MINERALS FILL INTERSTICES OF SILICIFIED, BRECCIATED MUDSTONE. ORE BODY NO. 1, CONTROLLED BY SUBPARALLEL SPLIT IN NEAR-VERTICAL N 80 TO 85 E TRENDING LOS OCHOS FAULT, IS PIPELIKE SHOOT TRIANGULAR IN PLAN. ORE BODY NO. 2 LIES 380 FT WEST OF NO. 1

References

Reference (Deposit): MALAN, R.C., AND RANSPOT, H.W., 1959, GEOLOGY OF THE URANIUM DEPOSITS IN THE COCHETOPA MINING DISTRICT, SAGUACHE AND GUNNISON COUNTIES, COLORADO: ECON. GEOLOGY, V. 54, NO. 1, P. 1-19.

Reference (Deposit): NELSON-MOORE, J.L., COLLINS, D.B., AND HORNBAKER, A.L., 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: COLORADO GEOLOGICAL SURVEY BULL. 40, P. 391-392

Reference (Deposit): OLSON, J.C., AND STEVEN, T.A., 1976, GEOLOGIC MAP OF THE RAZOR CREEK DOME QUADRANGLE, SAGUACHE COUNTY, COLORADO: USGS MAP MF-748

Reference (Production): COLO. DIV. MINES ANNUAL OPERATOR REPTS.

Colorado Mining Photos

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