La mineralización de las minas Bella Blenda y Cristal Blenda, Distrito Minero Marayes, provincia de San Juan

CASTRO DE MACHUCA, BRÍGIDA; MEISSL, ESTELA; MOGESSIE, ABERRA; BJERG, ERNESTO; CONTE-GRAND, ALICIA; PONTORIERO, SANDRA; SUMAY, CELINA; DELPINO, SERGIO; GALLIEN, FLORIAN

Río Cuarto (Córdoba)

Congreso; 10° Congreso de Mineralogía y Metalogenia (10° MINMET); 2010

Asociación Mineralógica Argentina - Universidad Nacional de Río Cuarto

The Bella Blenda and Cristal Blenda Pb-Zn-Ag mines, located in south-eastern Sierra de La Huerta, province of San Juan, are replacement vein-type deposits hosted in crystalline basement rocks (mainly marbles). Mineralized samples from these mines have been investigated using a JEOL JSM 6310 electron microprobe and a scanning electron microscope. The study reveals the presence of granular aggregates of pyrite-arsenopyrite-sphalerite-chalcopyrite-galena±tetrahedrite as the dominant metallic phases, with supergene hematite, and quartz-carbonates-chalcedony as gangue minerals. Mineral paragenesis, variations in the Fe content in sphalerite and strong optical and compositional zoning in arsenopyrite and pyrite, suggest that mineralization took place at  363 ºC (Asp-Py) and that the evolution of the mineralized hydrothermal fluids was a continue process with decreasing temperature.