The Pioneer - Lilyama is a copper mine located in El Dorado 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
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Pioneer - Lilyama MRDS details
Site Name
Primary: Pioneer - Lilyama
Secondary: Little Emma
Secondary: Volo
Commodity
Primary: Copper
Secondary: Gold
Secondary: Silver
Tertiary: Iron
Tertiary: Tungsten
Location
State: California
County: El Dorado
Land Status
Not available
Holdings
Not available
Workings
Type: Underground
Ownership
Owner Name: Wilcox - Lilyama Mining Co. (F.R. Wicks, Mgr.)
Production
Year: 1946
Time Period: - 1946
Material type: ORE
Description: Cp_Grade: ^Avg. 2.5 % Cu.
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: Cascade-Sierra Mountains
Physiographic Section: Sierra Nevada
Mineral Deposit Model
Not available
Orebody
Form: PODS
Structure
Type: L
Description: Faults, Joints: Lilyama Area, Member Faults Trend Approximately East And Dip 42 - 65 South, With Apparent Displacements Of Less Than 5 Ft.
Alterations
Not available
Rocks
Not available
Analytical Data
Not available
Materials
Ore: Chalcopyrite
Ore: Pyrite
Ore: Idocrase
Gangue: Quartz
Gangue: Garnet
Gangue: Epidote
Gangue: Magnetite
Comments
Comment (Workings): LILYAMA MINE: 4 ADITS TOTAL LENGTH GREATER THAN 1,000 FT., DEVELOPED THROUGH VERTICAL RANGE OF 132 FT., NOT CONNECTED UNDERGROUND. PIONEER MINE: 4 SHAFTS AND AN ADIT, OF THESE ONLY ONE 80 FT. SHAFT AND A SHORT CROSSCUT WERE ACCESSIBLE.
Comment (Deposit): TACTITE PODS WHICH RANGE IN SIZE FROM SMALL PODS TO THOSE 100 OR MORE FT. IN WIDTH. THE SULFIDES OCCUR AS IRREGULAR MASSES OR VEINLETS AND ARE ASSOCIATED WITH ABUNDANT EUHEDRAL MAGNETITE CRYSTALS.
Comment (Production): 1860'S WORKED AS 2 SEPERATE MINES, MAIN COPPER DEPOSIT DISCOVERED 1889 - 1890. 1955 REHABILITATED THE MINE, SOME ORE HAS BEEN PRODUCED AND STOCKPILED AWAITING COMPLETION OF WORK ON MILL. PRODUCTION TABLE FIGURES ARE FROM THE LILYAMA MINE.
Comment (Geology): GEOL.DESC: MOST WIDESPREAD ROCK IN THE STOCK IS A MED. TO COARSE GRAINED HORNBLENDE GRANODIORITE. A LIGHTER COLORED FACIES OF GRANODIORITE, NEARLY DEVOID OF MAFIC MINERALS UNDERLIES A LARGE AREA SE OF THE MINES. SYENITE PORPHYRY IS PRESENT AS A NARROW DIKE INTRUDING HORNFELS IN LOWER TUNNEL OF LILYAMA MINE. THE ADIT ALSO EXPOSES AN IRREGULAR DIKE OF DARK HORNBLENDE DIORITE WHICH IS PENETRATED BY STRINGERS OF GRANODIORITE. THE MOST PREVALENT METAMORPHIC ROCK IS THE FINE - GRAINED HORNFELS - LIGHT GRAYGREEN TO BLACK IN COLOR AND LOCALLY CONTAINING LARGE BIOTITE FLAKES. A GARNET QUARTZITE WITH A FINE - GRAINED SACCHAROIDAL TEXTURE CROPS OUT DIRECTLY ABOVE LILYAMA MINE WORKINGS. AT THE PIONEER MINE, A COARSELY CRYSTALLINE WHITE MARBLE IS THE IMPORTANT ROCK TYPE, IT TRENDS SLIGHTLY WEST OF NORTH, DIPS NEARLY VERTICAL AND IS NOT CONTINUOUS.
Comment (Deposit): THE ORE BODIES ARE THOSE PARTS OF THE TACTITE THAT CONTAIN COMMERCIAL AMOUNTS OF CHALCOPYRITE AND BORNITE. THE PIONEER MINE IS ABOUT 2,000 FT. FROM THE LILYAMA. V. 34, NO. 3, PL. II SHOWS THE PIONEER AS AN UNPATENTED CLAIM OF 20.65 ACRES.
References
Reference (Deposit): CLARK, W. B. AND CARLSON, D. W., 1956 : MINES AND MINERAL RESOURCES, EL DORADO COUNTY, CA.: CALIF. JOUR. MINES AND GEOLOGY, VOL. 52 , NO. 4 : DIV. OF MINES, P. 397 - 398 , 482 .
Reference (Deposit): COX, M. W., ETAL, 1948 : GEOLOGY OF THE LILYAMA AND PIONEER MINES, EL DORADO COUNTY, CA.: COPPER IN CALIFORNIA BULL. 144 : DIV. OF MINES, P. 43 - 47 .
Reference (Deposit): IN 1957, PRODUCED ALL OF THE COUNTY'S RECOVERABLE COPPER AND APPRECIABLE AMOUNTS OF GOLD AND SILVER -- U.S. BUREAU OF MINES MIN. YEARBOOK 1957, V. 3, P. 216
Reference (Production): COX, M. W., ETAL, 1948 , P. 44
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.
