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Grey Claim

Past Producer in Napa county in California, United States with commodities Chromium, Platinum, Palladium, Iridium, Ruthenium, Rhodium
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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. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Ore body information
  13. Controls for ore emplacement
  14. Economic information about the deposit and operations
  15. Land status
  16. Ownership information
  17. Production statistics
  18. Workings at the site
  19. Links to other databases
  20. Bibliographic references
  21. General comments
  22. Reporter information

Geologic information

Identification information

Deposit ID 10031651
MRDS ID M010775
Record type Site
Current site name Grey Claim

Geographic coordinates

Geographic coordinates: -122.37162, 38.8096 (WGS84)
Elevation 366
Location accuracy 100(meters)
Relative position 14 MI NORTHEAST OF CALISTOGA, 2 MI SOUTHWEST OF KNOXVILLE, Acc For Pge Collection Site

Site location context

Political divisions (FIPS codes)

Napa(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Knoxville(quadrangle 1:24,000 scale)

Healdsburg(quadrangle 1:100,000 scale)

Santa Rosa(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Lower Sacramento(hydrologic accounting unit)

Sacramento(hydrologic subregion)

California(hydrologic region)

Federal lands

Bureau of Land Management(Bureau of Land Management CA)

Bureau of Land Management CA BLM(Type of land area)

BLM(Federal land areas administered by BLM)

Geographic areas

Country State County
United States California Napa

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 011N 005W 11,12,13,14 California

Comments on the location information

  • UTM GIVEN IS FOR PGE SAMPLE SITE COLLECTION. LAT/LONG GIVEN IS FOR PROSPECT SYMBOL IN NW/4 SEC. 13. UTM FOR THIS LOCATION IS 4295650N, 554660E

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
Olivine Gangue

Analytical data

Result 1 PGE ANALYSIS: PT=124 PPB
Result PD=6 PPB
Result IR=56 PPB
Result RU=200 PPB
Result RH=11 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 Range Ophiolite
    Rock description Coast Range 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) -122.37162, 38.8096
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Shear Zone

Ore body information

  • General form CLOSELY PACKED LENSES

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 Private

Ownership information

  • Type Operator
    Owner Anglo American Mining Co.
    First year 1942
  • Type Owner
    Owner W. B. Shepherd
    First year 1942

Production statistics

  • Year 1918
    Material ORE
    Accuracy Estimate
    Description Ap_Grade: ^38-45% Cr2o3
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Cr2O3 Chromium Chromium 42wt-pct

Comments on the production information

  • CUTS BADLY CAVED IN 1942 AND NO ORE SEEN IN PLACE, BUT ABOUT 200 TONS OF ORE WERE STACKED NEAR WORKINGS

Workings at the site

  • Type of workings Surface/Underground
    Overall depth 2.44M
    Overall length 21.34M
    Overall width 3.05M

Comments on the workings information

  • 8 FT SHAFT AT THE BOTTOM OF AN OPEN CUT 20 FT DEEP. TOPOGRAPHIC MAP SHOWS SEVERAL PROSPECT SYMBOLS IN AREA

Reference information

Bibliographic references

  • Deposit

    DOW, D.H., AND THAYER, T.P., 1946, GEOLOGICAL INVESTIGATIONS OF CHROMITE IN CALIFORNIA: CALIFORNIA DIVISION OF MINES BULLETIN 134, PT. 2, CH. 1, P. 21.

  • 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

    AVERITT, PAUL, 1945, QUICKSILVER DEPOSITS OF THE KNOXVILLE DISTRICT, NAPA, YOLO, AND LAKE COUNTIES, CALIFORNIA: CALIFORNIA JOURNAL OF MINES AND GEOLOGY V. 41, NO. 2, PL. 6.

General comments

Subject category Comment text
Deposit AGGREGATE OF LENSES EXTENDS FOR 25 FT AND IS 3-6 FT WIDE AND 30 FT DEEP IN A SHEAR ZONE.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-73 Gere, W. U.S. Geological Survey
Updater 01-FEB-90 Peterson, Jocelyn A. U.S. Geological Survey

Beyond USGS

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

Maps centered on this site

Authoritative California resources

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