Black Jack

The Black Jack is a manganese mine located in Alameda county, California at an elevation of 2,280 feet.

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.

Site Name

Primary: Black Jack

Commodity

Primary: Manganese

Location

State: California
County: Alameda

Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Not available

Workings

Not available

Ownership

Owner Name: Leslie Holm
Years: 1950 -

Production

Not available

Deposit

Record Type: Site
Operation Category: Producer
Operation Type: Unknown
Years of Production:
Organization:
Significant: N
Deposit Size: S

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

Analytical Data

Not available

Materials

Not available

Comments

Comment (Location): LOCATED IN NW 1/4 NE 1/4 SECTION 14

Comment (Production): PAST PRODUCTION IS 40 TONS. MINE LIES 750 FT. FROM THE ARROYO MOCHO ROAD. THE ORE BODY RANGES IN THICKNESS FROM 1.7 TO 4 FT. AND AVERAGES 2.5 FT. IT LIES PARALLEL TO THE BEDDING OF THE ENCLOSING GRAY RADIOLARIAN CHERT AND SHALE. THE STRIKE RANGES FROM N. 25 DEG. E. TO N. 20 DEG. W. AND THE DIP FROM 25 DEG. TO 55 DEG. W

Comment (Workings): DRIFT 60 FT. TO ORE BODY, CONTINUES 30 FT.FARTHER FOLLOWING ORE BODY ALONG A COURSE N.20 DEG W,RAISE 8 FT., SECOND DRIFT FOLLOWS ORE BODY ALONG A COURSE N. 10 DEG. W FOR 40 FT.

Comment (Geology): GEOL.DESC: ORE BODY IS IN A BED OF MASSIVE GREY CHERT, WITH IRREGULAR POCKETS OF SILICEOUS OXIDE ORE. THE CHERT AND THE ORE ARE CUT BY NUMEROUS VEINS OF QUARTZ. THE ORE BODY LIES PARALLEL TO BEDDING OF ENCLOSING RADIOLARIN CHERTS AND SHALES.

References

Reference (Deposit): CALIF. JOUR. MINES & GEOL. V. 46, NO.2, APRIL, 1950, P.343, PL. 58

Reference (Deposit): DOM BULL. 125, P.97

Reference (Deposit): BULL. 152, P.16

Reference (Deposit): BULL 140 , P. 66 , PL. 1 (GEOLOGY)

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.