Mine detail: Little Jenny Mine

Previously called 'Jenny MineJennie Mine'

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Location: Saguache County, Colorado, United States, North America
Lat / long: 38.32945, -106.13032
dep_id: 10012556
mrds_id: D008234
Commodity type: metallic
Major mineral: Copper, Silver, Zinc, Lead
Minor mineral: Gold
Operation type: Unknown
Production size: Small ammount of material produced
Development status: Past Producer
ore: Chalcopyrite, Galena, Pyrite, Stromeyerite, Tennantite
gangue: Apatite, Quartz, Rhodochrosite, Rhodonite
work_type: Underground
alteration: Early Barren Stage Of Alteration By Fumarolic Or Acid-Hot Spring Activity Resulted In Intense Silicification, Wallrock Replacement By Jasper And Alteration Products Hematite, Diaspore, Alunite, Barite, Zunyite, Rutile, And Kaolin Minerals. Later Mineralizing Stage By Alkaline Or Neutral Solution Deposit Ore And Gangue And Caused Micaceous Alteration(Sericite And Chlorite) And Calcite, Quartz, And Pyrite.
conc_proc: Norhtern Part Of District Characterized By Low- To Intermediate-Temperature Hydrothermal Formation Of Quartz Veins With Relatively High Sulfide Content (Pb, Zn, Cu, Ag, And A Little Au) And Some Au-Ag Tellurides. Southern Part Characterized By Low-Temperature Hydrothermal Formation Of Quartz-Rhodochrosite-Fluorite Veins With Minor Sulfide Content But High Ag. Secondary Enrichment Was Shallow And Important In Early Production. Oxidation Of Rhodochrosite Veins In Southern Area Resulted In Formation Of Mn Ores And Moderate Ag Enrichment.
ore_ctrl: See Comments
Reporter: Schwochow, Stephen D.
hrock_unit: Rawley Andesite
hrock_type: Andesite
arock_unit: Rawley Andesite
arock_type: Andesite
Structure: Sawatch Range, San Juan Volcanic Field, Rio Grande Rift, Bonanza Caldera
tectonic: Central Cordillera (Southern Rocky Mtns.)
Year first produced: 1883
yr_lst_prd: 1958
References:
  • Deposit:: PATTON, H.B., 1916, GEOLOGY AND ORE DEPOSITS OF THE BONANZA DISTRICT, SAGUACHE COUNTY, COLORADO; COLORADO GEOLOGICAL SURVEY BULL. 9, 136 P.
  • Deposit:: BURBANK, W.S., 1932, GEOLOGY AND ORE DEPOSITS OF THE BONANZA MINING DISTRICT, COLORADO; USGS PROF. PAPER 169, 166 P.
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