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

Long Ledge No. 1 Long Ledge Group

Past Producer in Fresno county in California, United States with commodity Chromium
Map
XML
JSON
KML
B

Geologic information

Identification information

Deposit ID 10043381
MRDS ID M100115
Record type Site
Current site name Long Ledge No. 1 Long Ledge Group
Alternate or previous names Wood's Grizzly Bear Mine

Geographic coordinates

Geographic coordinates: -119.29596, 36.87495 (WGS84)
Location accuracy 1000(meters)
Relative position Assumed Spot Sect. 24, Assumed Spot Sect. 24, Assumed Spot Sect. 24
(click for info)

Geographic areas

Country State County
United States California Fresno

Public Land Survey System information

Meridian Township Range Section Fraction State
Mount Diablo 012S 024E 24 California

Commodities

Commodity Importance
Chromium Primary

Materials information

Materials Type of material
Chromite Ore
Talc Gangue

Alteration

  • (Local) Serpentinization

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Gabbro
  • Host or associated Host
    Rock type Plutonic Rock > Ultramafic Intrusive Rock > Peridotite > Dunite

Nearby scientific data

(1) -119.29596, 36.87495
ListMap

Geologic structures

Type of structure Local
Structure description A Shear Zone Trends N 15 W Through Deposit

Ore body information

  • General form LINEAR POD, LENS
    Strike N 15 W
    Dip 85 E
    Thickness 1.83M
    Width 3.05M

Comments on the geologic information

  • THE CHROMITE DEPOSITS OF WATTS VALLEY OCCUR ON THE EASTERN LIMB OF A SYNCLINAL, NE PLUNGING ULTRAMAFIC SILL. THE EASTERN LIMB, KNOWN AS HOG MTN, IS A LITTLE OVER A MILE WIDE, WHILE THE WESTERN LIMB, WHICH FORMS RED MTN, AVERAGES 3 MILES WIDE. THE TWO LIMBS JOIN TO THE NW AND TOGETHER FORM A DISCONTINUOUS TRIANGULAR EXPOSURE OF PERIDOTITE 10 MILES LONG AND 8 MILES WIDE ACROSS THE BASE.

Economic information

Economic information about the deposit and operations

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

Mining district

District name Watts Valley Area

Land status

Ownership category National Forest

Production statistics

  • Year 1918
    Period 1915?-1918
    Material ORE
    Accuracy Estimate
    Description Cp_Grade: ^33% Cr2o3
    Importance Item Commodity Group Amount recovered Grade Recovery percentage
    Major Cr2O3 Chromium Chromium 33wt-pct

Comments on the production information

  • NO MINING SINCE 1918.

Reserves and resources

  • Type In-situ
    Estimate year 1948
    Total resources 3,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Chromium Cr2O3 5 wt-pct Chromium Major 1948

Comments on the reserve resource information

  • RYHEARSON ESTIMATED BLOCK OF ORE 275 X 25 X 10 FT STILL REMAINS IN DEPOSIT AS MASSIVE AND DISSEMINATED CHROMITE.

Comments on the workings information

  • WORKINGS CONSIST OF 2 COLINEAR OPEN CUTS, EACH 60 FT LONG. THE CUTS ARE 70 FT. APART ON A LINE N10W. BETWEEN THEM LIES A SMALL PROSPECT PIT AND SEVERAL PILES OF ORE. AT N END OF UPPER CUT THERE IS AN OPEN ADIT AND SHAFT.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS M100115

Bibliographic references

  • Deposit

    CDMG BULL 134, P. 91-93.

  • Deposit

    STINSON, M.C., 1975, MINERAL PROPERTY REPORT, CDMG UNPUBLISHED REPORT.

  • Production

    STINSON, 1975, MINERAL PROPERTY REPORT, CDMG.

  • Reserve-Resource

    CDMG BULL 134, P. 93.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-80 Oster, Karel L. (Albers, John P.) U.S. Geological Survey