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Freeport Tunnel

Prospect in Mineral county in Colorado, United States with commodity Silver
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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)
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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

Geologic structures

Type Description Terms
Regional San Juan Volcanic Field; La Garita, Creede, And Bachelor Calderas
Local 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

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1919
Discoverer Fred Monkemeyer
Discovery method Ore-Mineral In Place

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

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS D007963

Bibliographic references

  • Deposit

    EMMONS, W.H., AND LARSEN, E.S. 1923, GEOLOGY AND ORE DEPOSITS OF THE CREEDE DISTRICT, COLORADO: USGS BULL. 718, 198 P.

  • Deposit

    STEVEN, T.A., AND RATTE, J.C., 1965, GEOLOGY AND STRUCTURAL CONTROL OF ORE DEPOSITION IN THE CREEDE DISTRICT, SAN JUAN MOUNTAINS, COLORADO: USGS PROF. PAPER 487, 90 P.

  • Deposit

    LINDEMANN, J.W., AND OTHERS, EDS., 1981, FIELD TRIP NOTES, CREEDE MINING DISTRICT, SAN JUAN VOLCANIC PROVINCE, COLORADO: DENVER REGIONAL EXPLORATION GEOLOGISTS SOC. GUIDEBOOK

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