The Fort Seward is a manganese mine located in Humboldt county, California.
About the MRDS Data:
All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.
Mine Info
Satelite View
MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.
Fort Seward MRDS details
Site Name
Primary: Fort Seward
Commodity
Primary: Manganese
Location
State: California
County: Humboldt
Land Status
Not available
Holdings
Not available
Workings
Not available
Ownership
Owner Name: F. M. Doak (J.P. Warren In 1943?)
Production
Not available
Deposit
Record Type: Site
Operation Category: Producer
Operation Type: Unknown
Years of Production:
Organization:
Significant: N
Deposit Size: M
Physiography
General Physiographic Area: Pacific Mountain System
Physiographic Province: Pacific Border Province
Physiographic Section: California Coast Ranges
Mineral Deposit Model
Not available
Orebody
Not available
Structure
Not available
Alterations
Not available
Rocks
Name: Chert
Role: Host
Age Type: Host Rock
Age Young: Late Cretaceous
Name: Chert
Role: Host
Age Type: Host Rock Unit
Age Young: Late Cretaceous
Analytical Data
Not available
Materials
Ore: Rhodochrosite
Ore: Braunite
Comments
Comment (Workings): OPEN CUTS; ADITS.
Comment (Geology): 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.
Comment (Production): 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.
Comment (Deposit): GLENN ADKINSON SHIPPED 10-12 CARLOADS, AVE. 43% MN, IN 1954.
Comment (Location): MAY BE IN SE 1/4 SECTION 15 ; INFO FROM LAND.ST :UNDETERMINED
References
Reference (Deposit): CALIF. JOUR. MINES & GEOLOGY, V. 37,NO. 4, OCT. 1941, P. 519
Reference (Deposit): DOM BULL. 152, 1950, PP. 67-69
Reference (Deposit): USBM R.I. 5579, P. 6
California Gold
"Where to Find Gold in California" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in California. Read more: Where to Find Gold in California.
