Commodities
PrimaryCopper
Commodity typeM
Deposit
Model184: Massive sulfide, kuroko
Deposit sizeS
WorkingsUnderground
Orebody formLENTICULAR
Ore control1. Belt Of Intense Chloritization, 2. Chloritiz Slate And Schist. Afforded Most Favorable Envioroment For Penetration And Replacement By Copper - Bearing Solutions, Granodiorite Did Not. 3. "Footwall Fault" And Subsidiary Faults And Fissures. 4. Larger Ore Bodies Are Parallel To Segments Of "Footwall Fault" Which Have A More Northerly Strike.
Materials
Ore mineralsAndalusite, Bornite, Chalcopyrite, Cuprite, Ilmenite, Malachite, Pyrite, Rutile, Sphene
GangueCalcite, Epidote, Hematite, Jasper, Quartz
Geology
Host rockSlate,Schist
StructureSee Comments
AlterationChloritization
Economic & production
Development statusProducer
Production years1861 - 1866 , 1867 , 1942 , 1943 , 1944 , 1945
Identification
Deposit ID10028815
MRDS IDM006029
Alternate namesKeystone
RegionNA
Data scoreB
Coordinates37.98713, -120.64768
References
CLARK, W. B. AND LYDON, P. A., 1962 , MINES AND MINERAL RESOURCES OF CALAVERAS COUNTY, CALIFORNIA; COUNTY REPT. 2 ; CALIF. DIV. MINES AND GEOLOGY, P. 27 .HEYL, G. R., 1948 , ORE DEPOSITS OF COPPEROPOLIS, CALAVERAS COUNTY, CALIFORNIA; COPPER IN CALIFORNIA BULL. 144 ; DIV. OF MINES, P. 103 - 106 .STRATEGIC MINERALS INVEST. PRELIM. MAP 3-183HEYL, G. R., 1948 , P. 96 - 97 (SEE REF.)HEYL, G. R., 1948 , P. 106 (SEE REF.)