The Big Reef is a manganese mine located in San Bernardino 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.
Big Reef MRDS details
Site Name
Primary: Big Reef
Secondary: Black Butte
Secondary: Hangover
Secondary: Bobbie Sullivan
Secondary: End Line
Secondary: Clark
Secondary: Clark No. 1
Secondary: Next Time
Secondary: Pisgah
Secondary: Willkie
Commodity
Primary: Manganese
Location
State: California
County: San Bernardino
Land Status
Not available
Holdings
Not available
Workings
Not available
Ownership
Not available
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: Intermontane Plateaus
Physiographic Province: Basin And Range Province
Physiographic Section: Sonoran Desert
Mineral Deposit Model
Not available
Orebody
Not available
Structure
Not available
Alterations
Not available
Rocks
Name: Andesite
Role: Associated
Age Type: Host Rock
Age Young: Pliocene
Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene
Analytical Data
Analytical Data: AVERAGE GRADE 30 TO 35 PERCENT MANGANESE
Materials
Ore: Psilomelane
Ore: Pyrolusite
Comments
Comment (Geology): GEOL.DESC: BRECCIATED ZONE 6 TO 8 FT. WIDE IN ANDESITE IN WHICH FRAGMENTS OF THE WALL ROCK ARE CEMENTED BY MANGANESE OXIDE. WELL DEFINED VEINLETS OF MANGANESE OXIDE AND CALCITE CUT THROUGH THE MATRIX. THE ORE BODY DEVELOPED ALONG A FISSURE WHICH HAS A SMOOTH FOOTWALL AND A GRADATIONAL HANGING WALL. THE ORE IS MAINLY PSILOMELANE-TYPE, AND SOME SOFT, BLACK CRYSTALLINE MINERAL, PROBABLY PYROLUSITE. A FIBROUS DARK-GREY OR BLACK MINERAL IS PRESENT WITH IMPURE SOFT BLACK OXIDE.
References
Reference (Deposit): D.O.M. BULL. 152 1950 PP. 188 - 191
Reference (Deposit): D.O.M. BULL. 125 1943 P. 160
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.
