La Union Mine

Occurrence in Puntarenas, Costa Rica with commodities Gold, Silver
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Ore body information
  12. Economic information about the deposit and operations
  13. Mining district
  14. Ownership information
  15. Workings at the site
  16. Links to other databases
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10007906
MRDS ID CS00141
Record type Site
Current site name La Union Mine

Geographic coordinates

Geographic coordinates: -84.72077, 10.15802 (WGS84)

Site location context

Political divisions (FIPS codes)

Puntarenas(province)

Costa Rica(country)

North America(continent)

Land(continent)

Geographic areas

Country State
Costa Rica Puntarenas

Comments on the location information

  • NEAR MIRAMAR. INCLUDES THE NEGRA, REINA, BONANZA, AND SANTA RITA VEINS. THE MIRAMAR DISTRICT IS THE MONTE DE ORO DISTRICT OF REITZ (1902).

Commodities

Commodity Importance
Gold Primary
Silver Secondary

Materials information

Materials Type of material
Chalcopyrite Gangue
Galena Gangue
Pyrite Gangue
Quartz Gangue
Sphalerite Gangue

Alteration

  • (Local) Silicification Of Andesite Locally Near Quartz Veins And Development Of Chlorite, Sericite, And Calcite With Lt 1 % Disseminated Pyrite.

Analytical data

Result ORE AVERAGES $5-$8/T AU (IN 1902?)

Mineral occurrence model information

Model code 151
USGS model code 25d
Deposit model name Epithermal vein, Sado
Mark3 model number 28

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite

Nearby scientific data

(1) -84.72077, 10.15802

Economic information

Ore body information

  • General form VEIN
    Strike N 10 W
    Dip VERTICAL

Comments on the geologic information

  • INTERMEDIATE DIKE PRESENT AT THE MINE.

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic
Significant No

Mining district

District name Miramar District

Ownership information

  • Type Operator
    Owner J. W. Kerr (Formerly)
  • Type Owner
    Owner Stephen C. Lamb; Empresa Minerales Montes Del Oro, S. A. Formerly By Union Mining Co.

Workings at the site

  • Type of workings Unknown
    Overall depth 367M

Reference information

Bibliographic references

  • Deposit

    REITZ, M. F., 1902, THE GOLD MINES OF COSTA RICA: ENG. MIN. J., V. 74, P. 212.

  • Deposit

    BENNETT, EVAN, 1939, GOLD MINING IN COSTA RICA: ENG. MIN. J., V. 140, P. 56-58.

  • Deposit

    DIRECCION GENERAL DE GEOLOGIA, MINAS E HIDROCARBUROS (DGMH) UNPUBLISHED FILES VIEWED 1986.

  • Deposit

    VISITED BY USGS SCIENTISTS, 1986. ORGANIZACION DE LOS ESTADOS AMERICANOS, 1978, DIAGNOSTICO DEL SECTOR MINERO: SAN JOSE, ORGANIZACION DE LOS ESTADOS AMERICANOS, 91 P.

  • Deposit

    U.S. GEOLOGICAL SURVEY, DIRECCION GENERAL DE GEOLOGIA, MINAS E HIDROCARBUROS, UNIVERSIDAD DE COSTA RICA, 1987, MINERAL RESOURCE ASSESSMENT OF THE REPUBLIC OF COSTA RICA: U.S. GEOLOGICAL SURVEY MISCELLANEOUS INVESTIGATION SERIES MAP I-1865, 75 P.

General comments

Subject category Comment text
Deposit VEINS STRIKE N 10 W, DIP VERTICAL. THE VETA NEGRA WAS RICHEST AND WIDEST AT 245 M DEPTH AND WAS WORKED DOWN TO 367 M. VEINS UP TO 10 CM THICK IN DUMP SAMPLES.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAR-1986 Howe, Stephen S. (Cox, Dennis P.) U.S. Geological Survey PARSED HOST ROCK AND ASSOCIATED ROCK INFORMATION FROM OLD SINGLE VALUED FIELD TO NEW MULTIVALUED FIELD
Editor 27-APR-1995 Mosier, Dan U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.