Pioneer - Lilyama

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

Name: Pioneer - Lilyama  

State:  California

County:  El Dorado

Elevation:

Commodity: Copper

Lat, Long: 38.83528, -120.96722

Map: View on Google Maps

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.


Satelite image of the Pioneer - Lilyama

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


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