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  3. Mineral Resource Data System (MRDS)

Freeport Tunnel

Prospect in Mineral county in Colorado, United States with commodity Silver
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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 10012364
MRDS ID D007963
Record type Site
Current site name Freeport Tunnel

Geographic coordinates

Geographic coordinates: -106.93451, 37.8714 (WGS84)
Elevation 3094
Relative position 1.3 MILES N15W FROM CREEDE (B.M. 8853 AT NORTH END OF TOWN)

Site location context

Political divisions (FIPS codes)

Mineral(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Creede(quadrangle 1:24,000 scale)

Del Norte(quadrangle 1:100,000 scale)

Durango(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Rio Grande Headwaters(hydrologic unit)

Rio Grande Headwaters(hydrologic accounting unit)

Rio Grande Headwaters(hydrologic subregion)

Rio Grande(hydrologic region)

Federal lands

Rio Grande National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Colorado Mineral

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 042N 001W 24 SW Colorado

Comments on the location information

  • S-T-R, LAT-LONG, AND ELEV DETERMINED FROM EMMONS AND LARSEN'S (1923) TOPO MAP (1:24,000). MINE OR CLAIM LIES ON SE SIDE OF BACHELOR MTN. SW OF BACHELOR AND COMMODORE MINES. ; INFO FROM LAND.ST :(1976)

Commodities

Commodity Importance
Silver Primary

Materials information

Materials Type of material
Acanthite Ore
Barite Gangue
Hematite Gangue
Jarosite Gangue
Limonite Gangue

Alteration

  • (Local) Silicification

Analytical data

Result G.T. 3 OZ/TON AG

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Quartz Latite
    Rock unit name Fisher Creek Quartz Latite
    Rock description Fisher Creek Quartz Latite
    Stratigraphic age (youngest) Oligocene
    Stratigraphic age (youngest) Oligocene
    Stratigraphic age (youngest) Oligocene
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Conglomerate
    Rock unit name Commodore Conglomerate Member Of Creede Formation;Monkemeyer Sandstone Member Of Creede Formation
    Rock description Commodore Conglomerate Mbr. Of Creede Formation;Monkemeyer Sandstone Mbr. Of Creede Formation

Nearby scientific data

(1) -106.93451, 37.8714
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description San Juan Volcanic Field; La Garita, Creede, And Bachelor Calderas
Type of structure Local
Structure description Amethyst Fault, Bachelor Mtn. Paleovalley (Controlled By Creede Graben)

Controls for ore emplacement

  • Carbonaceous Matter In Sandstone; Porous, Altered, Sandy Matrix In Conglomerate

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1919
Discoverer Fred Monkemeyer

Mining district

District name Creede District

Land status

Ownership category Private

Ownership information

  • Type Operator
    Owner Minerals Engineering Co. (Meco)
    Home office Grand Junction, Co.
    First year 1981
  • Type Owner
    Owner Minerals Engineering Co. (Meco) And Homestake Mining Co.
    Home office Grand Junction, Co.
    First year 1981

Workings at the site

  • Type of workings Underground
    Length 207.26M

Comments on the workings information

  • ONE TUNNEL DRIVEN WESTERLY 680 FT

Comments on development

  • RICH ORES ASSAYING AS HIGH AS 800 OZ/TON AG WERE MINED AND QUICKLY DEPLETED FOLLOWING 1919 DISCOVERY. NO PROSPECTING UNTIL 1975 UNDER MECO-FREEPORT JOINT VENTURE; 1981 FEASIBILITY STUDY INDICATES PROVEN AND PROBABLE RESERVES OF 3.348 MILLION TONS OF ORE AT 6.39 OZ/TON AG. EXPLORATION AND EVALUATION CONTINUING.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit AG SULFIDES WITH TRACE OF BASE METALS ARE VERY FINELY DISSEMINATED IN 1) CARBONACEOUS, TUFFACEOUS, SILTY TO COARSE-GRAINED SANDSTONE IN LOWER MONKEMEYER SS., AND 2) IN SANDY MATRIX OF COMMODORE CONGLOMERATE AND ASSOCIATED WITH FE AND MN OXIDE ALTERATION OCCURRING AS FRACTURE AND PORE SPACE COATINGS. MINERALIZATION FOUND BOTH IN SILICIFIED AND NONSILICIFIED ROCK.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-SEP-1981 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.