San Luis Mine

Site Name

Primary: San Luis Mine
Secondary: El Plomo
Secondary: Rito Seco
Secondary: Plomo Mine
Secondary: Plomo district
Secondary: San Luis deposit

---

Commodity

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

---

Location

State: Colorado
County: Costilla
District: El Plomo 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

Type: Fee Ownership
Type: Private Lease

---

Workings

Type: Surface

---

Ownership

Owner Name: Battle Mountain Gold Co.
Percent: 100.0
Home Office: 333 Clay St, Houston, Tx 77002
Info Year: 1991

---

Production

Year: 1996
Year: 1995
Year: 1994
Year: 1993
Year: 1992
Year: 1991

---

Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: flat vein system
Plant Type: Leach
Operation Type: Surface
Mining Method: Open Pit
Milling Method: Heap Leach-Electrowin
Year First Production: 1991
Discovery Year: 1890
Years of Production:
Organization:
Significant: Y

---

Physiography

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

---

Mineral Deposit Model

Model Name: Epithermal veins
Model Name: Detachment-fault-related polymetallic Cu-Au-Ag-Pb-Zn deposits
Model Name: Gold on flat faults

---

Orebody

Not available

---

Structure

Type: L
Description: numerous high-angle faults also

Type: L
Description: prominent low-angle fault

---

Alterations

Alteration Type: L
Alteration: chlorite carbonate
Alteration Text: carbonate +/- chlorite replacements and veins

Alteration Type: L
Alteration: quartz muscovite pyrite
Alteration Text: quartz-muscovite-pyrite replacements and veins

Alteration Type: L
Alteration: Silicification
Alteration Text: silica breccia matrix replacement

Alteration Type: L
Alteration: quartz, hematite
Alteration Text: quartz + specular hematite veinlet and matrix filling

---

Rocks

Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Tertiary

Name: Felsic Volcanic Rock
Role: Associated
Age Type: Associated Rock
Age Young: Tertiary

Name: Granitic Gneiss
Role: Associated
Age Type: Associated Rock
Age Young: Miocene

Name: Biotite Gneiss
Role: Associated
Age Type: Associated Rock
Age Young: Paleoproterozoic

Name: Tectonite
Role: Host
Age Type: Host Rock
Age Young: Paleoproterozoic

---

Analytical Data

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

---

Materials

Ore: Gold
Gangue: Chlorite
Gangue: Hematite
Gangue: Quartz
Gangue: Pyrite
Gangue: Calcite
Gangue: Sericite
Gangue: Fluorite
Trace: Pyrrhotite
Trace: Silver
Trace: Molybdenite
Trace: Galena
Trace: Covellite
Trace: Chalcopyrite
Unknown: Goethite

---

Comments

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

Comment (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.

Comment (Production): 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.

Comment (Production): PRODUCTION FROM BATTLE MOUNTAIN GOLD COMPANY 1993 ANNUAL REPORT. P. 4.

Comment (Reserve-Resource): Deposit contained 15,430,100 grams (approximately 500,000 oz) of gold before mining. 425,000 ounces were considered recoverable.

Comment (Geology): 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.

Comment (Location): 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.

Comment (Reserve-Resource): 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.

Comment (Geology): 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.

Comment (Geology): 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).

---

References

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

Reference (Deposit): AMERICAN MINES HANDBOOK 1993, P.32.

Reference (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.

Reference (Geology): GOLD DEPOSIT, COSTILLA CO, COLORADO. GOLD '90 PROCEEDINGS OF THE AIME OF THE GOLD '90 SYMPOSIUM, SALT LAKE CITY,

Reference (Geology): UT, FEB. 26 - MAR 1, 1990; HAUSEN, D. M., ET AL, EDS.,

Reference (Geology): 1990, PP. 83-91.

Reference (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.

Reference (Production): BATTLE MOUNTAIN GOLD CO. 1995 ANNUAL REPORT, P12.

Reference (Deposit): MINING RECORD. GOLD PRODUCTION FOR SAN LUIS PROJECTED AT"

Reference (Deposit): 69,000 OZ. IN 1995. VOL106/N16. 4/19/95. P.7."

Reference (Deposit): BATTLE MOUNTAIN GOLD CO. 1995 FORM 10-K RPT, P8.

Reference (Deposit): BATTLE MOUNTAIN GOLD CO., 1996 FORM 10-K, PP. 4, 13.

Reference (Deposit): BATTLE MOUNTAIN GOLD CO., 1996 ANNUAL REPORT, P17.

Reference (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.

Reference (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.

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

Reference (Deposit): BATTLE MTN GOLD CO. 1994 ANNUAL REPORT, P.4.

Reference (Deposit): BATTLE MTN GOLD CO. 1995 ANNUAL REPORT, P.12.

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

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

Reference (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.

Reference (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.

Reference (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.

---

Colorado Mining Photos

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