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Fort Seward

Producer in Humboldt county in California, United States with commodity Manganese
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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. Ownership information
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10109219
MRDS ID M008740
Record type Site
Current site name Fort Seward

Geographic coordinates

Geographic coordinates: -123.7114, 40.20068 (WGS84)
Relative position 6 MI. BY ROAD TO FORT SEWARD ON THE NORTHWESTERN PACIFIC RAILROAD.

Site location context

Political divisions (FIPS codes)

Humboldt(county)

California(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Fort Seward(quadrangle 1:24,000 scale)

Garberville(quadrangle 1:100,000 scale)

Redding(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

South Fork Eel(hydrologic unit)

Northern California Coastal(hydrologic accounting unit)

Klamath-Northern California Coastal(hydrologic subregion)

California(hydrologic region)

Geographic areas

Country State County
United States California Humboldt

Public Land Survey System information

Meridian Township Range Section Fraction State
Humboldt 003S 004E 15 California

Comments on the location information

  • MAY BE IN SE 1/4 SECTION 15 ; INFO FROM LAND.ST :UNDETERMINED

Commodities

Commodity Importance
Manganese Critical Primary

Materials information

Materials Type of material
Braunite Ore
Rhodochrosite Ore

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Chemical Sediment > Chert
    Rock unit name Franciscan Complex
    Rock description Franciscan Complex
    Stratigraphic age (youngest) Late Cretaceous
    Stratigraphic age (youngest) Late Cretaceous

Nearby scientific data

(1) -123.7114, 40.20068
ListMap

Economic information

Ore body information

  • Dip VERTICAL
    Thickness 6.1M

Comments on the geologic information

  • ORE HOSTED IN FRANCISCAN COMPLEX--L. TO L. ; GEOL.DESC: ORE IS IN LENSES PARALLELING RADIOLARIAN CHERT. THE ORE ZONE, NEARLY VERTICAL IS BOUNDED ON THE SW. AND N.E. BY CHERT. THE PRIMARY MATERIAL IS A CREAM COLORED MANGANESE CARBONATE AND A BROWN SILICEOUS ORE. ORE ZONE 5 TO 20 FT THICK, AND IS OFFSET 10 FEET IN THE CENTRAL PART BY A FAULT.

Economic information about the deposit and operations

Development status Producer
Commodity type Metallic
Deposit size Medium
Significant No

Ownership information

  • Type Operator
    Owner F. M. Doak (J.P. Warren In 1943?)

Comments on the production information

  • OPERATIONS BEGAN IN NOV. 1917, AND IN 10 MONTHS 450 TONS OF ORE HAD BEEN SHIPPED. SHIPMENTS VARIED BETWEEN 15 AND 20 PERCENT SILICA. A GENERAL SAMPLE GAVE MANGANESE, 34.4 PERCENT, INSOLUBLE, 37.8 PERCENT; IRON, 1.3 PERCENT. DURING 1943-44 A TOTAL OF 3,010 LONG TONS WERE PRODUCED, AVERAGING 41.6 PERCENT MANGANESE. ADDITIONAL ORE CAN BE INFERRED TO EXIST.

Comments on the workings information

  • OPEN CUTS; ADITS.

Reference information

Bibliographic references

  • Deposit

    CALIF. JOUR. MINES & GEOLOGY, V. 37,NO. 4, OCT. 1941, P. 519

  • Deposit

    DOM BULL. 152, 1950, PP. 67-69

  • Deposit

    USBM R.I. 5579, P. 6

General comments

Subject category Comment text
Deposit GLENN ADKINSON SHIPPED 10-12 CARLOADS, AVE. 43% MN, IN 1954.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUN-1973 Gere, W. U.S. Geological Survey
Updater 01-DEC-1977 Killman, K.; 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.