Winchester Tunnel

Past Producer in Rio Grande county in Colorado, United States with commodities Gold, Silver, Copper
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. Mineral occurrence model information
  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. Workings at the site
  17. Links to other databases
  18. Bibliographic references
  19. General comments
  20. Reporter information

Geologic information

Identification information

Deposit ID 10014046
MRDS ID D010662
Record type Site
Current site name Winchester Tunnel

Geographic coordinates

Geographic coordinates: -106.59949, 37.4253 (WGS84)
Elevation 3607
Relative position 0.45 MILES S 46 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 NE SIDE OF SOUTH MTN 1640 FT SE OF CHANDLER PORTAL. PORTAL ELEV FROM STEVEN AND RATTLE (1960, PL.4). ; INFO FROM LAND.ST :1975

Commodities

Commodity Importance
Gold Primary
Silver Primary
Copper Secondary

Alteration

  • (Local) Quartz-Alunite Solfataric Alteration

Analytical data

Result ASSAY FROM CARPER (1914): 0.58 OZ/TON AU, 0.75 OZ/TON AG (AT $20.65/OZ AU, $0.60/OZ AG)

Mineral occurrence model information

Model code 154
USGS model code 25e
Deposit model name Epithermal quartz-alunite Au
Mark3 model number 38

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) -106.59949, 37.4253

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

Mining district

District name Summit (Summitville) District

Land status

Ownership category Private

Workings at the site

  • Type of workings Surface/Underground
    Length 682.75M

Comments on the workings information

  • TUNNEL DRIVEN S 62 TO 72 W FOR 100 FT INTO SE END OF VEIN ZONE. DRIFTS EXTEND NW INTO VEIN ZONE FOR 940 FT; 1200 FT OF WORKINGS IN COPPER HILL-ESMOND VEIN ZONE. ANNIE OPEN CUT DEVELOPED TO SURFACE ABOVE WINCHESTER LEVEL 350 FT NW OF PORTAL. IDA CUT ON SURFACE AT NW END OF TUNNEL 600 FT NW OF PORTAL.

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. WINCHESTER MINE ALSO EXTENDS SW INTO ANNIE BELLE VEIN AND INTO NW END OF COPPER HILL-ESMOND VEIN ZONE BENEATH DEL NORTE WORKINGS.

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.

Authoritative Colorado resources

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