Estrella Mine

Past Producer in San Luis Obispo county in California, United States with commodities Chromium, Platinum, Palladium, Iridium, Ruthenium, Rhodium
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. Controls for ore emplacement
  15. Economic information about the deposit and operations
  16. Land status
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. Reporter information

Geologic information

Identification information

Deposit ID 10043642
MRDS ID M100460
Record type Site
Current site name Estrella Mine
Related records 10237859, 10043645

Geographic coordinates

Geographic coordinates: -120.70264, 35.37803 (WGS84)
Elevation 497
Relative position ABOUT 6.5 MI NORTHWEST OF SAN LUIS OBISPO

Site location context

Political divisions (FIPS codes)

San Luis Obispo(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Atascadero(quadrangle 1:24,000 scale)

San Luis Obispo(quadrangle 1:100,000 scale)

San Luis Obispo(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Central Coastal(hydrologic unit)

Central California Coastal(hydrologic accounting unit)

Central California Coastal(hydrologic subregion)

California(hydrologic region)

Federal lands

Los Padres National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States California San Luis Obispo

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 029S 012E 28,29 S2 (28); S2 (29) California

Comments on the location information

  • IN LOS PADRES NATIONAL FOREST. ON SOUTH HALF OF SECTION LINE BETWEEN SEC. 28 AND SEC. 29. LOCATION GIVEN IS MINE SYMBOL SHOWN ON TOPO MAP SOUTHEAST OF CASTRO MINE NEAR SECTION LINE

Commodities

Commodity Importance
Chromium Critical Primary
Platinum Critical Tertiary
Palladium Critical Tertiary
Iridium Critical Tertiary
Ruthenium Critical Tertiary
Rhodium Critical Tertiary

Materials information

Materials Type of material
Chromite Ore
Opal Gangue
Tremolite Gangue

Alteration

  • (Local) Dunite And Peridotite Now Mostly Serpentinite

Analytical data

Result 1 PGE ANALYSIS: PT=20 PPB
Result PD=12 PPB
Result IR=93 PPB
Result RU=250 PPB
Result RH=1 PPB.

Mineral occurrence model information

Model code 15
USGS model code 8a
Deposit model name Podiform chromite (minor)
Mark3 model number none

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite
    Rock unit name Coast Ranges Ophiolite
    Rock description Coast Ranges Ophiolite
    Stratigraphic age (youngest) Late Jurassic
    Stratigraphic age (youngest) Late Jurassic
    Stratigraphic age (youngest) Late Jurassic
  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Dunite

Nearby scientific data

(1) -120.70264, 35.37803

Economic information

Geologic structures

Type of structure Local
Structure description Numerous Small Joints And Fissures

Ore body information

  • General form NARROW HIGH-GRADE STRINGERS

Controls for ore emplacement

  • Magmatic Segregation

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No

Land status

Ownership category National Forest

Comments on the production information

  • SAID TO HAVE PRODUCED IN 1918 SOME OF THE RICHEST ORE IN THE COUNTY. 100 LB HIGH-GRADE ORE ON DUMP IN 1941.

Comments on the reserve resource information

  • NO MINABLE ORE LEFT IN 1941

Workings at the site

  • Type of workings Underground
    Length 9.14M

Comments on the workings information

  • 2 SHORT ADITS; NORTH ADIT, 30 FT LONG, RUNS N60W

Reference information

Bibliographic references

  • Deposit

    WALKER, G.W., AND GRIGGS, A.B., 1953, GEOLOGICAL INVESTIGATIONS OF CHROMITE IN CALIFORNIA: CALIFORNIA DIVISION OF MINES BULLETIN 134, PT. 2, CH. 2, P. 82.

  • Deposit

    CARLSON, C.A., AND OTHERS, 1985, ANALYSES FOR PLATINUM-GROUP ELEMENTS IN SAMPLES FROM PODIFORM CHROMITE DEPOSITS, CALIFORNIA AND OREGON: U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 85-442, 14 P.

  • Deposit

    SMITH, C.T., AND GRIGGS, A.B., 1944, CHROMITE DEPOSITS NEAR SAN LUIS OBISPO, SAN LUIS OBISPO COUNTY, CALIFORNIA: U.S. GEOLOGICAL SURVEY BULLETIN 945-B, P. 36.

  • Deposit

    ALLEN, J.E., 1941, GEOLOGICAL INVESTIGATION OF THE CHROMITE DEPOSITS OF CALIFORNIA: CALIFORNIA JOURNAL OF MINES AND GEOLOGY V. 37, NO. 1, P. 161.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-1981 Oster, Karel L. (Albers, John P.) U.S. Geological Survey
Updater 01-FEB-1990 Peterson, Jocelyn A. U.S. Geological Survey

Beyond USGS

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

Authoritative California resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.