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Thornburg Mine

Past Producer in Saguache county in Colorado, United States with commodity Uranium
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Alteration
  9. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Land status
  16. Ownership information
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10013146
MRDS ID D009285
Record type Site
Current site name Thornburg Mine
Alternate or previous names Los Ochos Mine, Thornburg No. 1 Mine, T-1 Mine, Los Ochos Claims

Geographic coordinates

Geographic coordinates: -106.74701, 38.36944 (WGS84)
Elevation 2640
Relative position 15 MILES S 38 E FROM GUNNISON

Site location context

Political divisions (FIPS codes)

Saguache(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Razor Creek Dome(quadrangle 1:24,000 scale)

Saguache(quadrangle 1:100,000 scale)

Montrose(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Tomichi(hydrologic unit)

Gunnison(hydrologic accounting unit)

Gunnison(hydrologic subregion)

Upper Colorado(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management CO)

Bureau of Land Management CO BLM(Type of land area)

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States Colorado Saguache

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 047N 002E 04 NE OF NE Colorado

Comments on the location information

  • ON PROMINENT KNOLL EAST OF UNNAMED TRIBUTARY OF COCHETOPA CREEK ; INFO FROM LAND.ST :1976

Commodities

Commodity Importance
Uranium Primary

Comments on the commodity information

  • 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

Materials information

Materials Type of material
Pitchblende Ore
Uranophane Ore
Zippeite Ore
Barite Gangue
Chalcedony Gangue
Marcasite Gangue

Alteration

  • (Local) Kaolinitization, Sericitization, Chloritization, Hematite Staining

Analytical data

Result 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.

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Quartz Monzonite
    Rock unit name Quartz Monzonite Of Cochetopa Creek
    Rock description Quartz Monzonite Of Cochetopa Creek
    Stratigraphic age (youngest) Neoproterozoic
    Stratigraphic age (youngest) Neoproterozoic
  • Host or associated Associated
    Rock type Plutonic Rock > Pegmatite
  • Host or associated Host
    Rock type Metamorphic Rock > Schist
    Rock unit name Salt Wash Member of Morrison Formation
    Rock description Salt Wash Member of Morrison Formation
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Mudstone
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone

Nearby scientific data

(1) -106.74701, 38.36944
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description San Juan Volcanic Field; Gunnison Uplift
Type of structure Local
Structure description Cochetopa Dome; Los Ochos Fault; Razor Creek Dome

Controls for ore emplacement

  • Silicification, Fracturing, Brecciation Of Sedimentary Rocks Along Los Ochos And Related Faults

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1954
Year of first production 1954
Year of last production 1962

Mining district

District name Cochetopa (Cochetopa Creek) District

Land status

Ownership category BLM Administrative Area

Ownership information

  • Type Owner-Operator
    Owner Gunnison Mining Co.
    First year 1962

Comments on the production information

  • 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

Workings at the site

  • Type of workings Underground
    Area 3.076HA
    Length 762M
    Overall length 438.91M
    Overall width 70.1M

Comments on the workings information

  • 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

Comments on development

  • DISTRICT MINED PREVIOUSLY FOR AU AND BASE METALS. GUNNISON MINING CO. DISCOVERED URANIUM IN 1954 ALONG LOS OCHOS FAULT.

Reference information

General comments

Subject category Comment text
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

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1982 Schwochow, Stephen D. Colorado Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Colorado resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.