Commodities
PrimaryZinc, Gold, Silver, Copper, Lead
Commodity typeM
Deposit
Deposit typeVEINS
Deposit sizeY
Ore controlTHE DEPOSITS ARE FISSURE VEINS ALONG TWO SETS OF FRACTURES. VEIN MATERIAL INCLUDES PYRITE, ARGENTIFEROUS AND AURIFEROUS GALENA (2.5-8 KG SILVER PER TON), SMALL AMOUNTS OF CHALCOPYRITE, TETRAHEDRITE, STIBNITE, MAGNETITE, RUBY SILVER, AND NATIVE SILVER. ARSENOPYRITE FORMS PRISMS AS LONG AS 5 CM. GOLD FROM THIS VEIN OF ARSENOPYRITE CONTAINED, ACCORDING TO VELARDE, 25-30 GRAMS OF GOLD AND 500-800 GRAMS OF SILVER PER TON. TETRAHEDRITE SEEMS TO BE MORE ABUNDANT IN THE UPPER LEVELS OF THE MINES AND ACCORDING TO VELARDE CONTAINED AS MUCH AS 90-100 KG OF SILVER PER TON. GANGUE IS MAINLY AMORPHOUS OR CRYSTALLIZED QUARTZ WITH MINOR AMOUNTS OF BARITE, CALCITE, AND RHODOCHROSITE OR RHODONITE.
Geology
StructureTHE AREA IS UNDERLAIN BY ESSENTIALLY FLAT-LYING VOLCANIC ROCKS OF PRESUMED TERTIARY AGE THAT ARE CALLED BY HARRISON 'UPPER LAVA AND ASH GROUP'. THESE VOLCANICS ARE MORE THAN 1000 M THICK (AS MUCH AS 1800), AND REST UNCONFORMABLY ON TIGHTLY FOLDED DARK LIMESTONE. THE LAVAS RANGE IN COMPOSITION FROM RHYOLITE TO BASALT BUT ARE PREDOMINANTLY GREEN TO BLACK PORPHYRITIC ROCKS OF ANDESITIC OR DACITIC COMPOSITION. THE BEDS ARE GENTLY FOLDED. THE VOLCANIC ROCKS ARE CUT BY RHYOLITE OR TRACHYTE. CUTTING THE VOLCANIC ROCKS ARE A SERIES OF ESSENTIALLY VERTICAL FRACTURES.
AlterationWALL ROCKS BLEACHED AND ALTERED TO SERICITE, CHLORITE, CALCITE, AND EPIDOTE, AND ALSO ARE SILICIFIED, PYRITIZED.
Economic & production
Development statusProducer
First production1852
Discovery year1852
Identification
Deposit ID60001612
MRDS IDW002266
Alternate namesCoricancha Veins
RegionSA
Data scoreD
Coordinates-11.84787, -76.23302
References
SIMONS, FRANK, 1960, UNPUBLISHED REPORT, P. 1352PERU-MAPA METALOGENETICO, 1969, AND, GUIA PARA EL MAPA METALOGENETICO DEL PERU, SOCIEDAD NACIONAL DE MINERIA Y PETROLEO, LIMA, PERU, NOV. 1969VELARDE, CARLOS E., 1899, EXTRACTO DEL INFORME SOBRE LAS MINAS Y OFICINA DE PARAC: SOC. NAC. DE MINERIA BOL., V. 2, P. 382-392PETERSEN, ULRICH, 1955, GEOLOGIA DE LA REGION MINERA VISO-ARURI: SOC. NAC. DE MINERIA Y PETROLEO BOL., SER. 2, NO. 42.NOBLE, D.C. AND VIDAL, C.E., 1994, GOLD IN PERU: SEG NEWSLETTER, APRIL 1994, NO. 17, P. 1, 6-13.HARRISON, JOHN V., 1951B, GEOLOGIA ENTRE POMACOCHA Y QUEBRADA TINAJA: SOC. GEOL. PERU BOL., V. 23, 28P, GEOLOGIC MAP.