Emma Mine

The Emma Mine is a gold, silver, and lead mine located in Dolores county, Colorado at an elevation of 8,819 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: Emma Mine
Secondary: Patented Claims: Great Bear, MS 12930
Secondary: Lion, MS 12930
Secondary: Sirius, MS 12931
Secondary: Little Emma, MS 12951a
Secondary: Orion, MS 12953a
Secondary: Brooklyn, MS 18498
Secondary: May Flower, MS 18499
Secondary: Unpatented Claims: Emmarette
Secondary: Barbara
Secondary: Patricia
Secondary: Cynthia
Secondary: Modern
Secondary: Queenmary
Secondary: Modern Gold
Secondary: Modern Mines
Secondary: Normandic
Secondary: Emmarette Mill Site
Secondary: Modern Gold Mill Site
Secondary: Modern Mines Mil Site

Commodity

Primary: Gold
Primary: Silver
Primary: Lead
Secondary: Coal
Tertiary: Zinc
Tertiary: Copper

Location

State: Colorado
County: Dolores
District: Lone Cone (Dunton) 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.
Administrative Organization: San Juan N. F.

Holdings

Not available

Workings

Not available

Ownership

Owner Name: Rado Reef Resources
Home Office: Stoner, Co.
Years: 1980 -

Production

Year: 1929
Description: Ap_Grade: ^111 Oz/Ton Ag, 2.4 Oz/Ton Au (Crude)
Year: 1928
Description: Ap_Grade: ^50 Oz/Ton Ag, 0.1 Oz/Ton Au (Milling)
Year: 1928
Description: Ap_Grade: ^100 Oz/Ton Ag, 2.4 Oz/Ton Au (Crude)
Year: 1922
Description: Ap_Grade: ^123.51 Oz/Ton Ag, 1.16 Oz/Ton Au (Crude)
Year: 1921
Description: Ap_Grade: ^86.2 Oz/Ton Ag, 0.71 Oz/Ton Au, 3.5% Zn (Crude)
Year: 1913
Description: Ap_Grade: ^259.83 Oz/Ton Ag, 3.47 Oz/Ton Au
Year: 1913
Description: Ap_Grade: ^202.2 Oz/Ton Ag, 3.17 Oz/Ton Au
Year: 1913
Description: Ap_Grade: ^253.7 Oz/Ton Ag, 2.72 Oz/Ton Au
Year: 1920
Description: Ap_Grade: ^100 Oz/Ton Ag, 0.68 Oz/Ton Au (Crude)
Year: 1928
Description: Ap_Grade: ^114 Oz/Ton Ag, 6.73 Oz/Ton Au, 2.2% Pb

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1885
Year Last Production: 1980
Discovery Year: 1880
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Intermontane Plateaus
Physiographic Province: Colorado Plateaus
Physiographic Section: Canyon Lands

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Type: R
Description: San Juan Uplift, Paradox Basin

Type: L
Description: Rico Dome, Dunton Syncline, Emma Fault

Alterations

Not available

Rocks

Name: Gabbro
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene

Analytical Data

Not available

Materials

Ore: Chalcopyrite
Ore: Pyrite
Ore: Argentite
Ore: Galena
Ore: Polybasite
Ore: Pyrargyrite
Ore: Coal
Ore: Sphalerite
Gangue: Melanterite
Gangue: Epsomite
Gangue: Gypsum
Gangue: Quartz
Gangue: Barite

Comments

Comment (Location): (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). MINE LOCATED ON SOUTH SIDE OF WEST DOLORES RIVER 0.45 MILE BELOW DUNTON. CLAIMS EXTEND ALONG EMMA FAULT SE BETWEEN EAGLE CREEK AND FALL CREEK AND NW ACROSS WEST DOLORES RIVER. EMMA COAL BANK WORKINGS LIE EAST OF FALL CREEK AT CONFLUENCE OF WEST AND EAST FORKS. ELEV AND LAT-LONG GIVEN ARE FOR EMMA SHAFT (SE SE SEC. 32). ; INFO FROM LAND.ST :1975

Comment (Deposit): NORTH- AND NW-DIPPING DOLORES FM RED BEDS CUT BY GENERALLY NW-TRENDING EMMA FAULT, DIPPING 80 TO 85 NE, FORMING WEST BOUNDARY OF GRABEN; BEDS DIP NE WITHIN GRABEN NEAR MINE. SE OF MINE, GENERALLY NE- TO ENE-TRENDING CROSS FAULT INTERSECTS EMMA FAULT. JUST INSIDE EMMA HANGING WALL, MICROGABBRO DIKE TRENDS SUBPARALLEL TO EMMA FAULT AND DIPS 50 NE. BASTIN (1922) DESCRIBED VEIN AS UP TO 4 FT WIDE AND CONSISTING OF IRREGULAR QUARTZ VEINLETS AND CHALCOPYRITE, QUARTZ-LINED VUGS; IN PLACES ORE FILLS SPACES BETWEEN BRECCIA FRAGMENTS. KRANTZ AND FREEMAN (1923) DESCRIBED ORE AS SIMILAR TO THAT AT SMUGGLER MINE: SPHALERITE, PYRITE, GALENA, CHALCOPYRITE, AND ARGENTITE AS INCLUSIONS IN SPHALERITE; NONBANDED. POST-MINERALIZATION FRACTURES CUTTING ORE ARE FILLED WITH SECONDARY ORES PROUSTITE, PYRARGYRITE, CHALCOPYRITE, AND ARGENTITE. WARM WATERS RISING ALONG VEIN EVOLVED CO2, H2S, AND DEPOSITED FERRUGINOUS CALCITE AND VARIOUS SULFATES. BLEACHING EXTENDS 8 TO 10 FT BEYOND VEIN AND IS CHARACTERIZED BY

Comment (Deposit): DISSEMINATED PYRITE. COAL MINED FROM THIN SEAMS IN DAKOTA SANDSTONE ON WEST LIMB OF DUNTON SYNCLINE WHERE INTRUDED BY AND POSSIBLY LOCALLY UPGRADED BY LAMPROPHYRE SILL.

Comment (Workings): MAP PREPARED BY RADO REEF RESOURCES (1979) SHOWS MINE TO BE DEVELOPED BY FOUR OR FIVE TUNNEL LEVELS AND 165-FT VERTICAL SHAFT OFF WHICH SIXTH LEVEL DEVELOPED. NO. 1 TUNNEL LOCATION AND EXTENT UNKNOWN. NO. 2 LEVEL DRIVEN GENERALLY SE OR SSE ALONG EMMA VEIN FOR AT LEAST 1850 FT. NO. 3 LEVEL LIES ABOUT 75 FT BELOW NO. 2, DRIVEN GENERALLY SE OR SSE ALONG EMMA VEIN FOR AT LEAST 160 FT. NO. 4 LEVEL LIES ABOUT 100 FT BELOW NO. 3, DRIVEN GENERALLY SE OR SSE ALONG EMMA VEIN FOR AT LEAST 2550 FT. NO. 5 LEVEL LIES ABOUT 100 FT BELOW NO. 4, DRIVEN GENERALLY SE OR SSE FOR AT LEAST 2800 FT, WITH SEVERAL WINZES. NO. 6 LEVEL LIES ABOUT 170 FT BELOW NO. 5, AND IS DRIVEN ABOUT 180 FT NORTH AND ABOUT 1330 FT SOUTH OF SHAFT AT DEPTH OF BETWEEN 140 AND 150 FT IN SHAFT. EMMA COAL BANK WORKINGS ARE ONE TUNNEL (ELEV 9920) DRIVEN GENERALLY SE, EXTENT UNKNOWN.

References

Reference (Deposit): BUSH, A.L., AND BROMFIELD, C.S., 1966, GEOLOGIC MAP OF THE DOLORES PEAK QUADRANGLE, DOLORES AND SAN MIGUEL COUNTIES, COLORADO: USGS MAP GQ-536.

Reference (Deposit): BASTIN, E.S., 1922, SILVER ENRICHMENT IN THE SAN JUAN MOUNTAINS, COLORADO: USGS BULL. 735-D, P. 116-120.

Reference (Deposit): COLORADO DIV. MINES INF. REPTS. AND ANNUAL OPERATOR REPTS.

Reference (Deposit): BLM MINERAL SURVEYS MS 12930, 12931, 12951A, 12953A, 18498, 18499

Reference (Deposit): KRANTZ, P.R., AND FREEMAN, W.H., 1923, A STUDY OF THE ORES OF DUNTON, DOLORES COUNTY, COLORADO: COLORADO SCHOOL OF MINES THESIS T-503.

Reference (Production): BASTIN, 1922, P. 120 (1913 FIGURES); COLORADO DIV. MINES ANNUAL OPERATOR REPTS. (1920-1980 FIGURES)

Colorado Mining Photos

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