Mine detail: Pioneer Mine

Previously called 'Big BonnieClaims: Rocky Point, Delta Fox, Sunset'

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Location

Lat / long:

38.11029, -105.33974

Resource(M)

Primary:	Silver, Gold
Secondary:	Lead, Copper
Ore:	Chalcopyrite, Covellite, Galena, Malachite, Pyrite, Silver, Stephanite, Tetrahedrite
Gangue:	Barite, Calcite, Clay
Discovery year:	1874

Production

Operation type:	Underground
Production size:	Small
Development status:	Past Producer

Geology

Host type:	Trachyte,Volcanic Breccia (Agglomerate)
Associated rock:	Rosita Andesite;Game Ridge Trachyte
Associated type:	Andesite
Structure:	Rosita Volcanic Center, Wet Mtns, Rosita Fault
Tectonic:	Central Cordillera (Southern Rocky Mtns)
Alteration processes:	Strong Argillization

References

MRDS	D008060
DEP	10012433
Reference	{Deposit:: CROSS, WHITMAN, 1896, GEOLOGY OF SILVER CLIFF AND THE ROSITA HILLS, COLORADO: USGS 17TH ANN. REPORT, PT 2, P. 263-403.}{Deposit:: SHARP, W.N., 1978, GEOLOGIC MAP OF THE SILVER CLIFF AND ROSITA VOLCANIC CENTERS, CUSTER COUNTY, COLORADO: USGS MAP I-1081, 1:24,000.}{Deposit:: Emmons, S.F., 1896, The mines of Custer County, Colorado: U.S. Geological Survey 17th Annual Report, Pt. 2, pp. 405-472.}{Production:: EMMONS, S.F., 1896}{Reserve-Resource:: Sunshine Mining Co. Colorado exploration files, unpublished data, Colorado Geological Survey.}
Reporter	Collins, Donna B., Beach, Richard A.