Manifestaciones epitermales auroargentíferas en la estancia El Águila, sector oriental del Macizo del Deseado, provincia de Santa Cruz

GUIDO, D.; TIBERI, P.

Río Cuarto

Congreso; VII Congreso de Mineralogía y Metalogenia (Minmet); 2004

El Águila area shows precious metal-rich mineralization, associated with four vein zones (El Águila, Sur, Negra and del Stockwork). These veins are hosted in volcanic rocks of the Bahía Laura Group and they are composed by quartz and chalcedony with typical epithermal textures. Ore minerals are pyrite and chalcopyrite disseminated in the veins, together with some Fe-Mn oxides. Hydrothermal alteration is restricted to veins and shows mainly silicification and argillization. Geochemical analysis evidence important anomalies in precious metals, very rich in Au (Ag:Au <17), with values up to 30.5ppm Au and 51ppm Ag. Oxygen isotope composition from El Águila vein quartz is -3.18? (δ18OFLUID), indicating a mixture of meteoric and magmatic waters in the hydrothermal fluids. Mineralization from El Águila farm is interpreted as low sulfidation epithermal type and can be added to the auroargentiferous Deseado province.