Merrimac Mine

The Merrimac Mine is a gold and silver mine located in Conejos county, Colorado at an elevation of 10,059 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Merrimac Mine
Secondary: Merrimac Group
Secondary: Patented Claims: Merrimac, MS 6200a
Secondary: Wild Cat, MS 6200a
Secondary: Telluride, MS 6200a
Secondary: Bismuth, MS 6200a
Secondary: Merrimac Mill Site, MS 6200b

Commodity

Primary: Gold
Primary: Silver
Secondary: Lead
Secondary: Copper
Tertiary: Molybdenum
Tertiary: Antimony
Tertiary: Zinc

Location

State: Colorado
County: Conejos
District: Ute (Platoro) District

Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Not available

Workings

Type: Surface/Underground

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Vein
Operation Type: Unknown
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains

Mineral Deposit Model

Model Name: Epithermal quartz-alunite Au

Orebody

Not available

Structure

Type: R
Description: San Juan Volcanic Field

Type: L
Description: Platoro Caldera, Summitville Caldera, Platoro Fault Zone, Cornwall Block

Alterations

Not available

Rocks

Name: Quartz Latite
Role: Associated
Age Type: Host Rock Unit
Age in Years: 29.800000+-
Dating Method: K-Ar
Age Young: Oligocene

Name: Quartz Latite
Role: Host
Age Type: Host Rock Unit
Age in Years: 29.800000+-
Dating Method: K-Ar
Age Young: Oligocene

Analytical Data

Not available

Materials

Ore: Pyrrhotite
Ore: Ferrimolybdite
Ore: Zinkenite
Ore: Sphalerite
Ore: Galena
Ore: Marcasite
Ore: Miargyrite
Ore: Proustite
Ore: Pyrargyrite
Ore: Polybasite
Ore: Digenite
Ore: Electrum
Ore: Silver
Ore: Gold
Ore: Chalcocite
Ore: Molybdenite
Ore: Covellite
Gangue: Quartz

Comments

Comment (Commodity): ORE MINERALS LISTED ABOVE ARE REPORTED FROM MAMMOTH-REVENUE MINE, AND ALTHOUGH NOT ALL ARE SPECIFICALLY NOTED AT OTHER MINES IN DISTRICT, THEY ARE GENERALLY APPLICABLE TO THEM (BIRD, 1973). ARSENOPYRITE REPORTED BY PATTON (1917) CITED FOR ENTIRE DISTRICT. PETZITE (TELLURIDE) REPORTED BY PATTON IN GILMORE AND PLATORO DISTRICTS WAS PROBABLY MISIDENTIFIED SULFIDE (BIRD, 1973). MINOR PRODUCTION OF CU AND PB UNCERTAIN DUE TO LACK OF OLDER PRODUCTION RECORDS.

Comment (Development): FIRST PRODUCER IN DISTRICT. ORIGINAL WORKING WAS OPEN CUT THAT YIELDED 3300 LB ORE

Comment (Location): CLAIMS LIE SOUTH OF CONEJOS RIVER SW OF TOWN AT NORTH BASE OF FOREST KING MTN. ELEV AND LAT-LONG GIVEN ARE FOR TUNNEL PORTAL IN NW NE NW SEC. 22 (SECTIONS PROJECTED INTO UNSURVEYED AREA). ; INFO FROM LAND.ST :1975

Comment (Workings): 14-FT-DEEP OPEN CUT; 175-FT SHAFT WITH 90- AND 146-FT DRIFTS

Comment (Deposit): MINE DEVELOPED ON MERRIMAC FAULT, ONE OF SEVERAL PRINCIPAL QUARTZ-PYRITE VEINS IN PLATORO FAULT ZONE. FAULT TRENDS GENERALLY N 40 W, DOWNDROPPED TO NE, BUT CHANGES TO GENERALLY N 20 W SOUTH OF ITS INTERSECTION WITH ENE-TRENDING EMMA FAULT ABOUT 0.35 MILE SE OF MINE. EXTENSION OF FAULT TO NW BEYOND MIX LAKE CAMPGROUND IS UNCERTAIN; BIRD (1973) INFERS EXTENSION SE INTO BIG LAKE RADIAL FRACTURE SYSTEM. WORCESTER (1919) DESCRIBES OUTCROPPING OF 2-INCH QUARTZ VEIN CARRYING MOLYBDENITE AND TRENDING N 15 TO 17 W, VERTICAL. IT WAS BELIEVED THAT SAME VEIN WAS CUT IN UPPER DRIFTS OF MINE.

References

Reference (Deposit): WORCESTER, P.G., 1919, MOLYBDENUM DEPOSITS OF COLORADO WITH GENERAL NOTES ON THE MOLYBDENUM INDUSTRY: CGS BULL. 14, P. 52.

Reference (Deposit): BLM MINERAL SURVEY MS 6200A&B

Reference (Deposit): BIRD, W.H., 1973, THE DEVELOPMENT OF THE SOUTHERN PORTION OF THE PLATORO CALDERA COMPLEX AND ITS RELATED MINERAL DEPOSITS, SOUTHEAST SAN JUAN MOUNTAINS, COLORADO: COLORADO SCHOOL OF MINES THESIS T-1440.

Reference (Deposit): PATTON, H.B., 1917, GEOLOGY AND ORE DEPOSITS OF THE PLATORO-SUMMITVILLE MINING DISTRICT, COLORADO: CGS BULL. 13.

Reference (Deposit): LIPMAN, P.W., 1974, GEOLOGIC MAP OF THE PLATORO CALDERA AREA, SOUTHEASTERN SAN JUAN MOUNTAINS, SOUTHWESTERN COLORADO: USGS MAP I-828.

Reference (Deposit): BIRD, W.H., 1972, MINERAL DEPOSITS OF THE SOUTHERN PORTION OF THE PLATORO CALDERA COMPLEX, SOUTHEAST SAN JUAN MOUNTAINS, COLORADO: MTN. GEOLOGIST, V. 9, NO. 4, P. 379-387.

Colorado Mining Photos

Check out this collection of Colorado's best historic mining photos: Incredible Photos of Colorado Mining Scenes.