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  2. Online Spatial Data
  3. Mineral Resource Data System (MRDS)

Twin Peaks

Past Producer in Napa county in California, United States with commodities Mercury, Chromium
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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. Alteration
  9. Host and associated rocks
  10. Nearby scientific data
  11. Geologic structures
  12. Controls for ore emplacement
  13. Economic information about the deposit and operations
  14. Mining district
  15. Ownership information
  16. Production statistics
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. Reporter information

Geologic information

Identification information

Deposit ID 10040802
MRDS ID M055676
Record type Site
Current site name Twin Peaks

Geographic coordinates

Geographic coordinates: -122.53496, 38.66238 (WGS84)
Elevation 549

Site location context

Political divisions (FIPS codes)

Napa(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Detert Reservoir(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)

Geographic areas

Country State County
United States California Napa

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 009N 006W 04 California

Commodities

Commodity Importance
Mercury Primary
Chromium Critical Tertiary

Materials information

Materials Type of material
Chromite Ore
Cinnabar Ore
Saponite Gangue

Alteration

  • (Local) Silica Carbonate Alteration Of Serpentine

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Serpentinite
    Stratigraphic age (youngest) Late Jurassic

Nearby scientific data

(1) -122.53496, 38.66238
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Serpentine - Sandstone Contact

Controls for ore emplacement

  • Contact

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic
Deposit size Small
Significant No
Year of first production 1902
Production years 1902, 1904, 1907 - 1908, 1911, 1915 - 1916, 1918, 1940 - 1943

Mining district

District name East Mayacmas

Ownership information

  • Type Owner
    Owner Louis D. Fay

Production statistics

  • Year 1962
    Period To 1962
    Material HG
    Accuracy Estimate
    Description Cp_Grade: ^4-10 Lb/Ton
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Mercury Mercury 3162g/mt

Workings at the site

  • Type of workings Underground
    Length 1280.16M
    Overall depth 60.96M

Comments on the workings information

  • NO WORK SINCE 1943, WORKINGS LARGELY INACCESSIBLE

Reference information

Bibliographic references

  • Deposit

    HOLMES, G. W., JR., 1965, MERCURY IN CALIFORNIA: IN USBM IC 8252

  • Deposit

    BAILEY, E. H., USGS, PERSONAL FILES

  • Deposit

    YATES, R. G. AND HILPERT, L. S., 1946, QUICKSILVER DEPOSITS OF THE EASTERN MAYACMAS DISTRICT, LAKE AND NAPA COUNTIES, CALIFORNIA: CALIF. JOUR. OF MINES AND GEOLOGY, V. 42, P. 231 - 286

  • Deposit

    BRADLEY, W.W., 1918, QUICKSILVER RESOURCES OF CALIFORNIA: CJMG BULL. 78, 389 P.

  • Deposit

    5) DAVIS, F.F., 1948, MINES AND MINERAL RESOURCES OF NAPA COUNTY, CALIF.: CJMG, V. 44, P. 176-183

  • Production

    USBM DATA

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-1976 Peterson, Jocelyn A. U.S. Geological Survey

Beyond USGS

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

External references

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.