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Montroy Tunnel

Past Producer in Rio Grande county in Colorado, United States with commodities Gold, Silver, Copper
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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. Alteration
  8. Host and associated rocks
  9. Nearby scientific data
  10. Geologic structures
  11. Controls for ore emplacement
  12. Economic information about the deposit and operations
  13. Mining district
  14. Land status
  15. Workings at the site
  16. Links to other databases
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10014041
MRDS ID D010657
Record type Site
Current site name Montroy Tunnel

Geographic coordinates

Geographic coordinates: -106.60088, 37.42669 (WGS84)
Elevation 3586
Relative position 0.48 MILES S 60 W FROM SUMMITVILLE

Site location context

Political divisions (FIPS codes)

Rio Grande(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Summitville(quadrangle 1:24,000 scale)

Antonito(quadrangle 1:100,000 scale)

Durango(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alamosa-Trinchera(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 Rio Grande

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 037N 004E 30 SW OF NW Colorado

Comments on the location information

  • ON NORTH SLOPE OF SOUTH MTN 850 FT SSE OF CHANDLER PORTAL. PORTAL ELEV FROM STEVEN AND RATTE (1960, PL. 4). ; INFO FROM LAND.ST :1975

Commodities

Commodity Importance
Gold Primary
Silver Primary
Copper Secondary

Alteration

  • (Local) Quartz-Alunite Solfataric Alteration

Host and associated rocks

  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Quartz Latite
    Rock unit name Quartz Latite Of South Mountain;Summitville Andesite
    Rock description Quartz Latite Of South Mountain;Summitville Andesite
    Stratigraphic age (youngest) Miocene
    Stratigraphic age (youngest) Miocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Quartz Latite
    Rock unit name Quartz Latite Of South Mountain;Summitville Andesite
    Rock description Quartz Latite Of South Mountain;Summitville Andesite

Nearby scientific data

(1) -106.60088, 37.42669
ListMap

Economic information

Geologic structures

Type of structure Regional
Structure description San Juan Volcanic Field
Type of structure Local
Structure description Platoro Caldera, Summitville Caldera, Summitville Fault, South Mountain Dome

Controls for ore emplacement

  • Quartz-Alunite Solfataric Replacement Bodies Following Nw-Trending Fractures Near Sw Margin Of South Mountain Feeder Conduit

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Discovery year 1879
Year of first production 1880

Mining district

District name Summit (Summitville) District

Land status

Ownership category Private

Workings at the site

  • Type of workings Underground
    Length 307.85M

Comments on the workings information

  • TUNNEL DRIVEN S 18 W FOR 170 FT INTO LITTLE ANNIE VEIN ZONE. AT LEAST 200 FT OF DRIFT ON VEIN. STOPES ABOVE MONTROY LEVEL AND BETWEEN MONTROY AND FRENCH LEVELS. CRAWFORD RAISE CONNECTS MONTROY AND FRENCH LEVEL. IDA SHAFT FROM SURFACE DRIVEN THROUGH MONTROY LEVEL JUST NORTH OF IDA CUT AND APPROX 150 SOUTH OF MONTROY PORTAL. 640 FT OF WORKINGS ON ONE OR TWO SW-PROJECTING VEINS.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit MINE DEVELOPED PRINCIPALLY ON LITTLE ANNIE VEIN ZONE, MOST EXTENSIVELY DEVELOPED VEIN AND RICHEST AU PRODUCER IN DISTRICT. DEPOSIT IS NW-SE-TRENDING, NEARLY VERTICAL, IRREGULARLY TABULAR MASS OF LIMONITE-STAINED, HIGHLY SILICIFIED ROCK, ALMOST ENTIRELY VUGGY QUARTZ WITH LOCAL SELVAGES OR INCLUSIONS OF QUARTZ-ALUNITE ROCK. ZONE APPARENTLY ENDS ON SE NEAR WINCHESTER PORTAL. NE-TRENDING CROSS-FRACTURES REFLECTED BY PROJECTIONS OF SILICIFIED ROCK AND ELONGATED PIPES, SUCH AS ANNIE BELLE VEIN EXTENDING SW FROM ANNIE OPEN CUT. HIGHLY OXIDIZED ORE (AURIFEROUS LIMONITE) STOPED ABOVE IDA LEVEL, SOME MINED BETWEEN IDA AND CHANDLER LEVELS. UNOXIDIZED AU-CU SULFIDE ORE ON CHANDLER LEVEL AND AS DEEP AS REYNOLDS LEVEL BUT CONTINUITY UNKNOWN. MONTROY WORKINGS ALSO EXTEND SW INTO ONE OR TWO SW-PROJECTING VEINS.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1983 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

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