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Keystone Group

Past Producer in Inyo county in California, United States with commodities Copper, Lead, Silver, 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. Geologic structures
  11. Ore body information
  12. Economic information about the deposit and operations
  13. Mining district
  14. Production statistics
  15. Links to other databases
  16. Bibliographic references
  17. General comments
  18. Reporter information

Geologic information

Identification information

Deposit ID 10033982
MRDS ID M020642
Record type Site
Current site name Keystone Group
Alternate or previous names Darwin-Keystone
Related records 10285394

Geographic coordinates

Geographic coordinates: -117.56534, 36.2608 (WGS84)
Relative position 1.75 MILES SE OF DARWIN

Site location context

Political divisions (FIPS codes)

Inyo(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Darwin(quadrangle 1:24,000 scale)

Darwin Hills(quadrangle 1:100,000 scale)

Death Valley(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Panamint Valley(hydrologic unit)

Northern Mojave(hydrologic accounting unit)

Northern Mojave-Mono Lake(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 Inyo

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 019S 041E 19,20,29,30 California

Commodities

Commodity Importance
Copper Primary
Lead Secondary
Silver Secondary
Gold Secondary

Materials information

Materials Type of material
Galena Ore
Calcite Gangue
Jasper Gangue
Limonite Gangue

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone

Nearby scientific data

(1) -117.56534, 36.2608
ListMap

Economic information

Geologic structures

Type of structure Local
Structure description Folds, Faults

Ore body information

  • Strike N
    Dip 60 W
    Thickness 3.05M

Comments on the geologic information

  • GEOL.DESC: MINE IS ON FOLDED AND FAULTED ROCK OF KEELER CANYON FORMATION. ROCKS ARE BROWN-WEATHERING SILTY LIMESTONE AND BLUE-GRAY LIMESTONE. LIMESTONE IS PARTLY ALTERED TO CALC-HORNFELS. DOMINANT FAULTS TREND BETWEEN N 70 E AND EAST, DIP STEEPLY.

Economic information about the deposit and operations

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

Mining district

District name Darwin

Production statistics

  • Year 1941
    Period 1940 - 1941
    Material ORE
    Accuracy Accurate
    Description Ap_Grade: ^.04 Oz Au/Ton, 27.9 Oz Ag/Ton, 25 % Pb, .6 % Zn, 20 % Iron.
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Ore Iron Iron 20wt-pct
    Trace Ore Zinc Zinc 1wt-pct
    Trace Ore Lead Lead 25wt-pct
    Trace Ore Silver Silver 788g/mt
    Ore Gold Gold 1g/mt

Comments on the production information

  • REPORTED: 800 TONS OF SORTED ORE SHIPPED FROM LOWER WINZE AND ZONE BETWEEN THE TWO WORKINGS, ORE AVERAGED 15 % PB, 28 OZ AG/TON, MINOR GOLD.

Comments on the workings information

  • LOWER WORKINGS; KEYSTONE ADIT, 626 FT. LONG, DRIFT 210 FT. LONG, 120 FT. OF CROSSCUTS, A 175 FT. STEEPLY INCLINED WINZE, SMALL STOPES. UPPER WORKINGS; MCDONALD ADIT. CAVED 145 FT. FROM PORTAL, 135 FT. OF DRIFTS, MINOR CROSSCUTS.

Reference information

General comments

Subject category Comment text
Deposit ORE IS HIGHLY OXIDIZED - POORLY EXPOSED, 2 - 10 FT. THICK. HAS BEEN EXPLOITED FOR STRIKE LENGTH OF 40 FT. UNDERGROUND.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-1978 Fraticelli, L. A. (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.