Otay Bentonite Deposit

Past Producer in San Diego county in California, United States with commodity Bentonite
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. Host and associated rocks
  9. Nearby scientific data
  10. Ore body information
  11. Economic information about the deposit and operations
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10023476
MRDS ID I000462
Record type Site
Current site name Otay Bentonite Deposit
Alternate or previous names Deposit Includes General Petroleum Co. Mine and Standard Oil Co. Mine.

Geographic coordinates

Geographic coordinates: -117.03418, 32.60007 (WGS84)
Elevation 107
Relative position 11 MILES S OF SAN DIEGO NEAR MEXICAN BORDER.

Site location context

Political divisions (FIPS codes)

San Diego(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Imperial Beach(quadrangle 1:24,000 scale)

San Diego(quadrangle 1:100,000 scale)

San Diego(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

San Diego(hydrologic unit)

Laguna-San Diego Coastal(hydrologic accounting unit)

Southern California Coastal(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California San Diego

Public Land Survey System information

Meridian Township Range Section Fraction State
18S;18S 001W;001W 17,18,19,20,29,30;25 California

Commodities

Commodity Importance
Bentonite Primary

Materials information

Materials Type of material
Bentonite Ore

Analytical data

Result BENTONITE HAS A HIGH BASE EXCHANGE CAPACITY. CHEMICAL ANALYSES OF THE CLAY SHOW: 49.56%-63.04% SIO2, 15.08%-18.44% AL2O3, 0.51%-3.44% FE2O3, 5.69%-7.84% MGO, 0.47%-1.37% CAO, 0.73%-3.4% NA2O.

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone
    Rock unit name San Diego Formation
    Rock description San Diego Formation
    Stratigraphic age (youngest) Pliocene
    Stratigraphic age (youngest) Pliocene
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Arkose
  • Host or associated Host
    Rock type Unconsolidated Deposit > Volcanic Ash

Nearby scientific data

(1) Pliocene marine rocks

Economic information

Ore body information

  • Thickness 2.74M

Economic information about the deposit and operations

Development status Past Producer
Commodity type Non-metallic
Significant No

Comments on the reserve resource information

  • THE RESERVES ARE A MINIMUM FOR THE NORTHERN PART OF THE OTAY VALLEY.

Reference information

Bibliographic references

  • Deposit

    CLEVELAND, G.B., 1960, GEOLOGY OF THE OTAY BENOTNITE DEPOSIT, SAN DIEGO COUNTY, CALIFORNIA: CALIFORNIA DIVISION OF MINES SPECIAL REPORT 64, 16 P

  • Production

    CLEVELAND, 1960.

General comments

Subject category Comment text
Deposit HIGH-GRADE CLAY UNDERLIES AN AREA OF 1.3 SQ. MILES AND IS AN ALTERATION PRODUCT OF VOLCANIC ASH. THE ORE OCCURS AT AN ELEVATION OF 350-375 FT IN THE NORTHERN PART OF THE OTAY VALLEY AND AT AN ELEVATION OF 325-350 FT IN THE SOUTHERN PART OF THE VALLEY. THE BED AVERAGES 3 FT THICK, BUT MAY BE AS THICK AS 9 FT.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAR-1990 Orris, Greta J. 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.