Logan Mine

The Logan Mine is a silver, lead, zinc, and gold mine located in Dolores county, Colorado at an elevation of 9,629 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

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Site Name

Primary: Logan Mine
Secondary: Logan Group
Secondary: Patented Claims: General Logan, MS 2476
Secondary: General Sherman, MS 2477
Secondary: General O. O. Howard, MS 2478
Secondary: General Sheridan, MS 2479
Secondary: Little Casper, MS 19665
Secondary: Goliath, MS 19665

Commodity

Primary: Silver
Primary: Lead
Primary: Zinc
Primary: Gold
Tertiary: Sulfur-Pyrite
Tertiary: Manganese

Location

State: Colorado
County: Dolores
District: Pioneer (Rico) District

Land Status

Land ownership: National Forest
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

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1885
Discovery Year: 1885
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

Model Name: Polymetallic replacement

Orebody

Not available

Structure

Type: R
Description: San Juan Uplift, Paradox Basin

Type: L
Description: Rico Dome, Blackhawk Fault, Princeton Fault

Alterations

Alteration Type: L
Alteration Text: Oxidation Of Sulfide Ores; Silicification And Sericitization Of Sandstone

Rocks

Name: Latite
Role: Associated
Age Type: Host Rock Unit
Age Young: Pennsylvanian

Name: Latite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Paleocene

Name: Latite
Role: Associated
Age Type: Associated Rock
Age Young: Paleocene

Name: Latite
Role: Associated
Age Type: Host Rock
Age Young: Pennsylvanian

Analytical Data

Analytical Data: ANALYSIS OF HALLOYSITE: 38.65% SIO2, 33.27% AL2O3, 0.22% FE2O3, 28.14% COMBINED H2O. ANALYSIS OF LIMESTONE: 55.1% CAO, 43.39% CO2 (BY DIFFERENCE), 0.80% SIO2, TRACE TIO2, 0.04% AL2O3, 0.07% FE2O3, 0.10% FEO (AS CARBONATE), 0.13% MNO (AS CARBONATE), 0.03% CUO (AS CARBONATE), 0.09% ZNO (AS CARBONATE), 0.25% MGO (AS CARBONATE), TRACE P2O5, TRACE S (AS PYRITE). ANALYSIS OF SANDSTONE: 83.95% SIO2, 8.92% AL2O3 (WITH SOME TIO2), 0.48% FE2O3, 0.13% FEO, 0.04% AG, TRACES PB AND CU, 0.97% MGO, 0.12% CAO, 0.06% NA2O, 3.09% K2O, 1.90% COMBINED H2O. ANALYSIS OF ALTERED SANDSTONE: 62.88% SIO2, 21.38% AL2O3 (WITH SOME TIO2), 1.09% FE2O3, LITTLE MNO, NONE TO TRACE AG, 0.34% PB, 2.00% MGO, 0.40% CAO, 0.07% NA2O, 6.59% K2O, 5.49% COMBINED H2O, 0.53% SO3.

Materials

Ore: Pyrite
Ore: Sphalerite
Gangue: Quartz
Gangue: Halloysite
Gangue: Sericite
Gangue: Gypsum
Gangue: Fluorite

Comments

Comment (Deposit): GENERALLY SOUTH-DIPPING MIDDLE AND UPPER HERMOSA SANDSTONE, LIMESTONE, AND SHALE COVERED BY EXTENSIVE LANDSLIDES BUT BELOW ARE CUT BY NW-TRENDING BLACKHAWK FAULT, DOWNTHROWN ON NE. ONE CROSSCUT SHOWS FAULT TO BE 12-FT VEIN OF QUARTZ AND PYRITE MASSES IN BROKEN COUNTRY ROCK AND GOUGE. TWO OR MORE BLANKET REPLACEMENT ORES OCCUR BETWEEN SANDSTONE AND LIMESTONE. NEAR LOGAN NO. 2 SHAFT, BLANKET IS IRREGULARLY DIPPING, CELLULAR, CRUMBLING LIMONITE GRADING INDISTINCTLY INTO FE-STREAKED, SERICITIZED SANDSTONE. NEARER LOGAN SHAFT, 3- TO 4-FT-THICK BLANKET UNDERLIES ALTERED SANDSTONE AND CONTAINS FRAGMENTS FROM IT, IS ROUGHLY LAMINATED OCHEROUS OR LIMONITIC MASS OVERLYING IRREGULAR LIMESTONE SURFACE AND SEPARATED FROM IT BY THIN, MINUTELY FISSURED, MANGANIFEROUS LAYER OF GPYSUM AND HALLOYSITE. THIS MAIN BLANKET COULD BE SAME AS THAT WORKED IN CHC AND WELLINGTON MINES.

Comment (Workings): OLD LOGAN SHAFTS INACCESSIBLE, DEPTH UNKNOWN. LOGAN TUNNEL, DRIVEN GENERALLY SE OR SSE, CONNECTS WITH LOGAN NO. 2 SHAFT AND WELLINGTON WORKINGS, AND LIES IN BLACKHAWK FAULT FOOTWALL WITH NE CROSSCUTS TO FAULT.

Comment (Deposit): Discovery Year: 1880S

Comment (Location): (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). ON WEST SLOPE OF CHC HILL (UNSURVEYED SECTION). ELEV AND LAT-LONG GIVEN ARE FOR LOGAN TUNNEL AND ARE FROM MCKNIGHT, 1974, PL. 1 (1930 BASE). ; INFO FROM LAND.ST :1975

References

Reference (Deposit): CROSS, WHITMAN, AND RANSOME, F.L., 1905, DESCRIPTION OF THE RICO QUADRANGLE: USGS FOLIO 130.

Reference (Deposit): BLM MINERAL SURVEYS MS 2476, 2477, 2478, 2479, 19665

Reference (Deposit): RANSOME, F.L., 1901, THE ORE DEPOSITS OF THE RICO MOUNTAINS, COLORADO: USGS 22D ANN. REPT., PT. 2, P. 390-392

Reference (Deposit): MCKNIGHT, E.T., 1974, GEOLOGY AND ORE DEPOSITS OF THE RICO DISTRICT, COLORADO: USGS PROF. PAPER 723.

Reference (Deposit): PRATT, W.P., AND OTHERS, 1969, GEOLOGIC MAP OF THE RICO QUADRANGLE, DOLORES AND MONTEZUMA COUNTIES, COLORADO: USGS MAP GQ-797.

Colorado Mining Photos

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