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Twenty Grand

Past Producer in Mono county in California, United States with commodities Gold, Silver, Lead, Copper
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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. Ore body information
  12. Economic information about the deposit and operations
  13. Land status
  14. Links to other databases
  15. Bibliographic references
  16. General comments
  17. Reporter information

Geologic information

Identification information

Deposit ID 10007218
MRDS ID C010640
Record type Site
Current site name Twenty Grand

Geographic coordinates

Geographic coordinates: -118.32038, 37.51272 (WGS84)
Elevation 1707
Relative position 8 MI. N LAWS

Site location context

Political divisions (FIPS codes)

Mono(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Chalfant Valley(quadrangle 1:24,000 scale)

Benton Range(quadrangle 1:100,000 scale)

Mariposa(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Crowley Lake(hydrologic unit)

Mono-Owens Lakes(hydrologic accounting unit)

Northern Mojave-Mono Lake(hydrologic subregion)

California(hydrologic region)

Federal lands

Inyo National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

White Mountains Wilderness(Wilderness)

Wilderness FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States California Mono

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 005S 033E 14 California

Comments on the location information

  • UTM ACC. NW 1/4 SE 1/4

Commodities

Commodity Importance
Gold Primary
Silver Primary
Lead Secondary
Copper Secondary

Materials information

Materials Type of material
Quartz Gangue

Alteration

  • (Local) Oxidation

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Quartzite

Nearby scientific data

(1) Cambrian marine rocks
ListMap

Economic information

Ore body information

  • Strike NE
    Dip 30 - 40 SE
    Thickness 6.1M

Comments on the geologic information

  • GEOL.DESC: VEIN QUARTZ BRECCIATED AND RECEMENTED

Economic information about the deposit and operations

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

Land status

Ownership category National Forest

Comments on the production information

  • A SMALL AMOUNT OF ORE WAS PRODUCED IN 1936. SMELTER RECOVERY RAN 9.45%PB, 1.26% CU, 1.89 OZ/TON AG, AND 0.25 OZ/TON AU. THERE IS NO RECORD OF EARLY GOLD PRODUCTION AT THIS MINE.

Comments on the workings information

  • 600 FT. ADIT, 120 FT. ADIT, 40 FT. ADIT, 60 FT. INCLINE, 40 FT. INCLINE W/200 FT. 15 DEGREE WINZE, 200 FT. ADIT, 2 300 FT. ADITS W/150 FT. OF CROSSCUTS AND DRIFTS. TOTAL UNDERGROUND DEVELOPMENT ABOUT 2000 FT.

Reference information

Bibliographic references

  • Deposit

    GOODWIN, J. G., 1957 , LEAD AND ZINC IN CALIFORNIA: CALIFORNIA JOURNAL OF MINES AND GEOLOGY, V. 53 , NOS. 3 & 4 , P. 569 .

  • Deposit

    TUCKER, W. B., AND SAMPSON, R. J., 1940 , MINERAL RESOURCES OF MONO COUNTY: CALIFORNIA JOURNAL OF MINES AND GEOLOGY, V. 36 , NO. 2 , P. 139 - 140 , PL. 1 .

  • Production

    GOODWIN ( 1957 )

General comments

Subject category Comment text
Deposit VEINS, 2 - 20 FT. THICK
Deposit COMPRISES 10 CLAIMS ; INFO.SRC : 1 PUB LIT

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-1979 Nelson, Scott C. (Albers, John, P.) U.S. Geological Survey CLEANED UP HOST ROCK TYPE
Updater 07-OCT-1991 Mosier, Dan U.S. Geological Survey AND ASSOCIATED ROCK TYPE.
Editor 27-APR-1995 Mosier, Dan U.S. Geological Survey PARSED HOST ROCK AND ASSOCIATED ROCK INFORMATION FROM OLD SINGLE VALUED FIELD TO NEW MULTIVALUED FIELD

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.