San Luis Mine

Past Producer in Costilla county in Colorado, United States with commodities Gold, Silver, Copper, Lead, Molybdenum, Zinc
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. Materials information
  8. Alteration
  9. Mineral occurrence model information
  10. Host and associated rocks
  11. Nearby scientific data
  12. Geologic structures
  13. Ore body information
  14. Economic information about the deposit and operations
  15. Mining district
  16. Mineral rights holdings
  17. Land status
  18. Ownership information
  19. Production statistics
  20. Reserves and resources
  21. Workings at the site
  22. Links to other databases
  23. Bibliographic references
  24. General comments
  25. Reporter information

Geologic information

Identification information

Deposit ID 10142482
MAS/MILS ID 0080230016
Record type Site
Current site name San Luis Mine
Alternate or previous names El Plomo, Rito Seco, Plomo Mine, Plomo district, San Luis deposit

Geographic coordinates

Point of reference Main Entrance
Geographic coordinates: -105.34196, 37.25753 (WGS84)
Elevation 2700
Location accuracy 100(meters)

Site location context

Political divisions (FIPS codes)

Costilla(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ojito Peak(quadrangle 1:24,000 scale)

Alamosa(quadrangle 1:100,000 scale)

Trinidad(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)

Geographic areas

Country State County
United States Colorado Costilla

Public Land Survey System information

Meridian Township Range Section Fraction State
New Mexico 035 N 015 E 16 Colorado

Comments on the location information

  • Near the western base of the Sangre de Cristo Mountains. It is five miles northeast of the town of San Luis. Mine is on the north side of Rito Seco, a westward-flowing perennial stream.

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Copper Secondary
Lead Secondary
Molybdenum Tertiary
Zinc Critical Tertiary

Materials information

Materials Type of material
Gold Ore
Hematite Gangue
Pyrite Gangue
Quartz Gangue
Chlorite Gangue
Fluorite Gangue
Sericite Gangue
Calcite Gangue
Chalcopyrite Trace
Covellite Trace
Galena Trace
Molybdenite Trace
Silver Trace
Pyrrhotite Trace
Goethite Unknown

Alteration

  • (Local) quartz, hematite
  • (Local) Silicification
  • (Local) quartz muscovite pyrite
  • (Local) chlorite carbonate

Analytical data

Result $5 TO $15/TON AU (VAN DEIST)
Result $2.50 TO $7/TON AU (GUNTHER)
Result TO 8 OZ AU AND 357 OZ AG (HOLMES) , ASSAY FROM TRACT ONE MILE EAST OF MINE \n

Mineral occurrence model information

Model code 281
USGS model code 37b
Deposit model name Gold on flat faults
Model code 82
USGS model code 22
Deposit model name Epithermal veins
Model code 129
USGS model code 40a
Deposit model name Detachment-fault-related polymetallic Cu-Au-Ag-Pb-Zn deposits

Host and associated rocks

  • Host or associated Host
    Rock type Tectonite
    Rock unit name brecciated gneiss and cataclasite
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Associated
    Rock type Metamorphic Rock > Gneiss > Felsic Gneiss > Biotite Gneiss
    Rock unit name biotite gneiss
    Stratigraphic age (youngest) Paleoproterozoic
  • Host or associated Associated
    Rock type Metamorphic Rock > Gneiss > Felsic Gneiss > Granitic Gneiss
    Rock unit name granitic gneiss
    Stratigraphic age (youngest) Miocene
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock
    Rock unit name felsite dikes
    Stratigraphic age (youngest) Tertiary
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite
    Rock unit name andesite dikes
    Stratigraphic age (youngest) Tertiary

Nearby scientific data

Main Entrance (1) -105.34196, 37.25753

Economic information

Geologic structures

Type of structure Local
Structure description prominent low-angle fault
Type of structure Local
Structure description numerous high-angle faults also

Ore body information

  • Strike N75E
    Dip 20S
    Thickness 30M
    Length 2500M
    Width 450M
    Area 240HA
    Depth to top 50M
    Field Value
    Type of Orebody #1 BRECCIA FILL
    Shape of Orebody #1 TABULAR
    Primary mode of Origin HYDROTHERMAL
    Primary Ore Control FAULTING
    Secondary Ore Control FRACTURING
    Degree of Wallrock Alter. INTENSE
    Type of Wallrock Alter. #1 SILICIFICATION
    Type of Wallrock Alter. #2 SERICITIC
    Type of Wallrock Alter. #3 PROPYLITIC
    Strike And Dip N75E:20S
    Minimum Depth to Top 0
    Avg. Thick. Unconsol. Mat. 8
    Min. Thick. Unconsol. Mat. 0
    Total Surface Area (HA) 240
    Future Surface Area (HA) 140
    Previous Surface Area (HA) 100
    Date of Last Modification 910730

Comments on the geologic information

  • Deposit is hosted in breccia developed along a low-angle fault. The fault is interpreted to be a detachment fault (Benson, 1997). Breccia has been silicified and mineralized. High-angle faults are present in the deposit as well. Some of these offset mineralization short distances. Some post-mineral movement on the low-angle fault has also been noted. Mineralization is thought to have occurred around 22 Ma.
  • West end of orebody is truncated by the high-angle Sangre de Cristo Fault which juxtaposes mineralized, brecciated Proterozoic rocks with sedimentary rocks of the Santa Fe Formation (R. Kirkham, personal. commun., 2005).
  • SAN LUIS GOLD DEPOSIT CONSISTS OF 2 TABULAR DEPOSITS: EAST ZONE (MATRIX 1) & WEST ZONE (MATRIX 2). GOLD MINERALIZATION OCCURS WITHIN AND BELOW A LOW-ANGLE FAULT ZONE IN CATACLASTICALLY DEFORMED PRECAMBRIAN METAMORPHIC ROCKS. HIGHER GRADE GOLD VALUES IN THE DEPOSIT ARE CLOSELY ASSOCIATED WITH SILICIFICATION AND QUARTZ- SERICITE-PYRITE ALTERATION. THE EAST ORE ZONE STRIKES EAST-WEST AND DIPS 15-25 DEGS SOUTH. ORE IS CONFINED TO BIOTITE GNEISS BRECCIA WITH MINOR AMOUNTS OCCURING BELOW IN BIOTITE GNEISS CATACLAS- ITE. WEST ORE ZONE STRIKE AND DIP IS ROUGHLY CONFORMABLE TO THE HOST FAULT BRECCIA. AS THE FAULT CHANGES FROM NEARLY EAST-WEST IN THE SOUTHERN PORTION TO NORTH-SOUTH IN THE NORTHERN PORTION, SO DOES THE STRIKE OF THE ORE DEPOSIT. THE HANGING WALL OF THE WEST ORE ZONE IS FAULT CLAY AND GNEISSIC GRANITE. THE WEST ORE ZONE IS CONFINED TO INTENSELY SILICIFIED AND SERICITIZED BIOTITE GNEISS BRECCIA AND CATACLASITE.

Economic information about the deposit and operations

Operation type Surface
Development status Past Producer
Commodity type Metallic
Significant Yes
Discovery year 1890
Mining method Open Pit
Year of first production 1991
Plant type Leach
Milling method Heap Leach-Electrowin

Mining district

District name El Plomo District

Mineral rights holdings

Type of mineral rights Private Lease
Type of mineral rights Fee Ownership

Land status

Ownership category Private

Ownership information

  • Type Owner-Operator
    Owner Battle Mountain Gold Co.
    Interest 100
    Home office 333 Clay St, Houston, Tx 77002
    Year 1991

Production statistics

  • Year 1991
    Accuracy Estimate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 684276.58g 0oz/st
  • Year 1992
    Accuracy Estimate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 1710691.45g 0oz/st
  • Year 1993
    Accuracy Estimate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2239450.63g 0oz/st
  • Year 1994
    Accuracy Estimate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2270554.11g 0oz/st
  • Year 1995
    Accuracy Estimate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2177243.67g 0oz/st
  • Year 1996
    Accuracy Estimate
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Gold Gold 2115036.7g 0oz/st

Comments on the production information

  • Modern mining of the deposit by Battle Mountain Gold Company began in 1991 and ended in early 1997. Total production from 1991 to 1996 was 360,000 oz of gold. Reclamation work began in 1997. Silver was also produced at the mine, but silver production was only half that of gold.
  • PRODUCTION FROM BATTLE MOUNTAIN GOLD COMPANY 1993 ANNUAL REPORT. P. 4.

Reserves and resources

  • Type In-situ
    Estimate year 1994
    Measured 11021500mt ore
    Total resources 11021500mt ore
    Commodity Subtype Grade units Group Importance Year
    Gold 1.4 g/mt Gold Major 1994

Comments on the reserve resource information

  • Deposit contained 15,430,100 grams (approximately 500,000 oz) of gold before mining. 425,000 ounces were considered recoverable.
  • M1C1=R1. RESERVE IS FOR EAST END ORE RESERVE. M2C1=R2. RESERVE IS FOR WEST END ORE RESERVE. M3C1=M1C1 + M2C1. COMBINED RESERVES OF EAST AND WEST ZONES. M9C4=M3C1.

Workings at the site

  • Type of workings Surface
    Area 57HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method ACTUAL
    Mining Method OPEN PIT
    Percent Waste Rock 54
    Avg. Overburden Thickness 50
    Primary Material Cover SAND, GRAVEL
    Percentage 10
    Secondary Material Cover HARDPAN
    Percentage 15
    Tertiary Material Cover M-HARD ROCKS
    Percentage 75
    Hardness of Ore M-HARD ROCKS
    Avg. Bench Height (meters) 4.6
    Max. Pit Slope (degrees) 30
    Capacity 6195
    Capacity Units MT ORE/DAY
    Preprod. Stripping Vol. 354
    Unit Production Cost 2.44
    Units of Production $/MT ORE
    Operating Days per Year 200
    Operating Shifts per Day 3
    Year of Information 1991
  • Type of workings Surface
    Area 57HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 2
    Status of Mining Method ACTUAL
    Mining Method OPEN PIT
    Percent Waste Rock 64.7
    Avg. Overburden Thickness 50
    Primary Material Cover SAND, GRAVEL
    Percentage 10
    Secondary Material Cover HARDPAN
    Percentage 15
    Tertiary Material Cover M-HARD ROCKS
    Percentage 75
    Hardness of Ore M-HARD ROCKS
    Avg. Bench Height (meters) 5
    Max. Pit Slope (degrees) 30
    Capacity 6195
    Capacity Units MT ORE/DAY
    Unit Production Cost 2.71
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 3
    Year of Information 1991
  • Type of workings Surface
    Area 57HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 3
    Status of Mining Method ACTUAL
    Mining Method OPEN PIT
    Percent Waste Rock 66.7
    Avg. Overburden Thickness 50
    Primary Material Cover SAND, GRAVEL
    Percentage 10
    Secondary Material Cover HARDPAN
    Percentage 15
    Tertiary Material Cover M-HARD ROCKS
    Percentage 75
    Hardness of Ore M-HARD ROCKS
    Avg. Bench Height (meters) 5
    Max. Pit Slope (degrees) 30
    Capacity 6195
    Capacity Units MT ORE/DAY
    Unit Production Cost 2.78
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 3
    Year of Information 1991
  • Type of workings Surface
    Area 57HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 4
    Status of Mining Method ACTUAL
    Mining Method OPEN PIT
    Percent Waste Rock 66.7
    Avg. Overburden Thickness 50
    Primary Material Cover SAND, GRAVEL
    Percentage 10
    Secondary Material Cover HARDPAN
    Percentage 15
    Tertiary Material Cover M-HARD ROCKS
    Percentage 75
    Hardness of Ore M-HARD ROCKS
    Avg. Bench Height (meters) 5
    Max. Pit Slope (degrees) 30
    Capacity 3664
    Capacity Units MT ORE/DAY
    Unit Production Cost 4.54
    Units of Production $/MT ORE
    Operating Days per Year 125
    Operating Shifts per Day 3
    Year of Information 1991

Comments on development

  • Previous companies to explore deposit: ASARCO, 1931 and 1959; Inspiration Copper Co., 1968; Earth Sciences, Inc., 1972-1987. Modern-era exploration and development work began in 1987.

Reference information

Bibliographic references

  • Geology

    Benson, R.G., and Jones, D.M., 1994, Geology of the San Luis gold deposit: New developments, Costilla County, Colorado: Society for Mining, Metallurgy, and Exploration, SME Annual Meeting, Albuquerque, New Mexico, 9 p.

  • Geology

    GOLD DEPOSIT, COSTILLA CO, COLORADO. GOLD '90 PROCEEDINGS OF THE AIME OF THE GOLD '90 SYMPOSIUM, SALT LAKE CITY,

  • Geology

    UT, FEB. 26 - MAR 1, 1990; HAUSEN, D. M., ET AL, EDS.,

  • Geology

    1990, PP. 83-91.

  • Production

    BATTLE MOUNTAIN GOLD CO. 1995 ANNUAL REPORT, P12.

  • Deposit

    AMERICAN MINES HANDBOOK 1993, P.32.

  • Deposit

    EPLER, BILL. SAN LUIS GOLD - BMG'S NEW PRODUCER IS UP & RUNNING, PAYDIRT MAG. (ROCKY MT ED), MAY 1991, PP 4A-6A

  • Deposit

    BATTLE MTN GOLD CO. 1994 ANNUAL REPORT, P.4.

  • Deposit

    BATTLE MTN GOLD CO. 1995 ANNUAL REPORT, P.12.

  • Deposit

    MINING RECORD. GOLD PRODUCTION FOR SAN LUIS PROJECTED AT"

  • Deposit

    69,000 OZ. IN 1995. VOL106/N16. 4/19/95. P.7."

  • Deposit

    BATTLE MOUNTAIN GOLD CO. 1995 FORM 10-K RPT, P8.

  • Deposit

    BATTLE MOUNTAIN GOLD CO., 1996 FORM 10-K, PP. 4, 13.

  • Deposit

    BATTLE MOUNTAIN GOLD CO., 1996 ANNUAL REPORT, P17.

  • Deposit

    Benson, R.G., 1997, Detachment fault-related mineralization in a rift setting at the San Luis gold deposit and Sangre de Cristo Mountains, Alamosa, Costilla, and Saguache Counties, Colorado: Golden, Colorado School of Mines, Ph.D. dissertation, 226 p.

  • Geology

    Benson, R.G., 1997, Detachment fault-related mineralization in a rift setting at the San Luis gold deposit and Sangre de Cristo Mountains, Alamosa, Costilla, and Saguache Counties, Colorado: Golden, Colorado School of Mines, Ph.D. dissertation, 226 p.

  • Deposit

    VAN DEIST, E.C., AND VAN DEIST, P.H., 1898, NOTES ON THE GEOLOGY OF THE WESTERN SLOPE OF THE SANGRE DE CRISTO RANGE IN COSTILLA COUNTY, COLO.: COLO, SCI. SOC. PROC., V. 5, P. 76-80.

  • Deposit

    GUNTHER, C.G., 1905, THE GOLD DEPOSITS OF PLOMO, SAN LUIS PARK, COLORADO: ECON. GEOLOGY, V. 1, P. 143-154.

  • Deposit

    RITTER, E.A., 1934, REPORT ON THE RITO SECO MINING PROPERTY LOCATED IN COSTILLA COUNTY, COLORADO: COLORADO STATE PLAN. COMM. UNPUB. REPI.

  • Development

    WEILKINSON, BRUCE, 1981, GOLD LODE STUDIED IN COSTILLA COUNTY: DENVER POST, 6/14/81, P. 46.

  • Geology

    Wallace, A.R., and Soulliere, S.J., 1996, Geologic map of the Ojito Peak quadrangle, Costilla County, Colorado: U.S. Geological Survey Miscellaneous Field Studies Map MF-2312-B, scale 1:24,000.

  • Deposit

    Benson, R.G., and Jones, D.M., 1994, Geology of the San Luis gold deposit: New developments, Costilla County, Colorado: Society for Mining, Metallurgy, and Exploration, SME Annual Meeting, Albuquerque, New Mexico, 9 p.

  • Reserve-Resource

    Benson, R.G., and Jones, D.M., 1994, Geology of the San Luis gold deposit: New developments, Costilla County, Colorado: Society for Mining, Metallurgy, and Exploration, SME Annual Meeting, Albuquerque, New Mexico, 9 p.

General comments

Subject category Comment text
Deposit HIGH LEVELS OF COPPER IMPEEDED GOLD RECOVERY, CAUSING THE CESSATION OF MINING IN OCTOBER 1996, PRODUCTION ENDED IN NOVEMBER OF 1996:

Reporter information

Type Date Name Affiliation Comment
Reporter 14-OCT-97 Buckingham, David A. U.S. Bureau of Mines
Updater 10-MAY-05 Keller, John W. Colorado Geological Survey
Editor 16-NOV-11 Wilson, Anna B U.S. 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.