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Tomboy & Eureka

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

Geologic information

Identification information

Deposit ID 10086528
MRDS ID X025429
Record type Site
Current site name Tomboy & Eureka
Related records 10117089

Geographic coordinates

Geographic coordinates: -120.8802, 39.48599 (WGS84)
Elevation 1280
Relative position 2 1/4 MI NW OF ALLEGHANY

Site location context

Political divisions (FIPS codes)

Sierra(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Pike(quadrangle 1:24,000 scale)

Truckee(quadrangle 1:100,000 scale)

Chico(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Yuba(hydrologic unit)

Lower Sacramento(hydrologic accounting unit)

Sacramento(hydrologic subregion)

California(hydrologic region)

Federal lands

Tahoe 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 Sierra

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 019N 010E 29 California

Commodities

Commodity Importance
Gold Primary

Materials information

Materials Type of material
Gold Ore
Pyrite Ore
Quartz Gangue

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
  • Host or associated Associated
    Rock type Plutonic Rock > Granitoid > Granite
  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
  • Host or associated Host
    Rock type Metamorphic Rock > Serpentinite
  • Host or associated Host
    Rock type Plutonic Rock > Granitoid > Granite

Nearby scientific data

(1) -120.8802, 39.48599
ListMap

Economic information

Ore body information

  • Strike NE
    Dip 67 SE

Comments on the geologic information

  • TOMBOY VEIN, OF QTZ & PORPHYRY, W GABBRO WALLS, 6-7 FT THICK STRIKES NE, DIPS 60-75S, W ABUNDANT SULFIDES. EUREKA VEIN 3-5 FT THICK, STRIKES N, DIPS FLAT TO E, W ORE IN QTZ LENSES. ADJOINS KATE HARDY MINE. BOTH VEINS EXHIBIT POST-MINERAL SHEARING. IN LOWER EUREKA TUNNEL, A DIKE OF GRANITE 3 FT THICK CUTS GABBRO & IS CUT BY SHEAR ZONES ACCOMPANYING VEIN. POST MINERAL SHEARING HAS LEFT QTZ OF EUREKA VEIN MUCH CRUSHED, IRREGULAR, IN PLACES ABSENT. WALL ROCK CARBONATE ALTERATION NOT PROMINENT EXCEPT CLOSE TO VEIN.

Economic information about the deposit and operations

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

Comments on the production information

  • NO OTHER PRODUCTION RECORD FOUND

Workings at the site

  • Type of workings Surface/Underground
    Area 16.188HA

Comments on the workings information

  • 2 ADITS, 1 SHAFT AT TOMBOY, SEVERAL SHAFTS & ADITS AT EUREKA, SURFACE CUTS.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit VEIN

Reporter information

Type Date Name Affiliation Comment
Reporter 01-MAR-1979 Hayden, F. (Albers, J.) 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.