Castro Mine

The Castro Mine is a chromium mine located in San Luis Obispo county, California at an elevation of 1,601 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

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Castro Mine

Commodity

Primary: Chromium

Location

State: California
County: San Luis Obispo

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

Not available

Workings

Not available

Ownership

Owner Name: Ernest Vollmer Jr.,
Home Office: P. O. Box 317, San Luis Obispo, Ca. 93406
Years: 1976 -

Owner Name: Castro Mining Co., San Francisco (Now Defunct)
Years: 1957 -

Production

Year: 1944
Time Period: 1942-1944
Material type: CON
Description: Cp_Grade: ^Avg. 42% Cr2o3
Year: 1920
Time Period: 1918-1920
Material type: CON
Description: Cp_Grade: ^Avg. 40% Cr2o3
Year: 1957
Time Period: 1918-1957
Material type: CON
Description: Cp_Grade: ^Avg. 42% Cr2o3

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1875
Year Last Production: 1957
Discovery Year: 1876
Discovery Method: Unknown
Years of Production:
Organization:
Significant: N
Deposit Size: M

Physiography

General Physiographic Area: Pacific Mountain System
Physiographic Province: Pacific Border Province
Physiographic Section: California Coast Ranges
Physiographic Detail: Santa Lucia Range

Mineral Deposit Model

Not available

Orebody

Form: LENSE

Form: LENSE

Structure

Type: R
Description: Dominant Trend Of The Sonta Lucia Range Is To The Nw.

Alterations

Not available

Rocks

Name: Dunite
Role: Host
Age Type: Host Rock
Age Young: Late Jurassic

Analytical Data

Analytical Data: CONCENTRATES AVERAGED 42% CR2O3 WITH A CR TO FE RATIO OF 2.4.

Materials

Ore: Chromite

Comments

Comment (Location): WORKINGS LIE NEAR FOOT OF NW TRENDING QUESTA RIDGE.

Comment (Workings): WORKINGS (1950'S) CONSISTED OF TWO LARGE OPEN PITS.

Comment (Geology): QUESTA RIDGE COMPOSED OF ULTRAMAFIC BODY TRENDING NW-SE.

Comment (Deposit): CHROMITE BODIES ELONGATE TO NW. CASTRO MINE PROPERTY IS PATENTED.

References

Reference (Production): STINSON, 1975

Reference (Deposit): STINSON, M. C., 1975, CDMG MINERAL PROPERTY REPORT, UNPUBLISHED

California Gold

"Where to Find Gold in California" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in California. Read more: Where to Find Gold in California.