Entrapment and re-equilibration of fluid inclusions in hydrothermal veins related to transtensional shear zones

SOSA, GRACIELA M.; DEMARTIS, MANUEL; MAFFINI, M. NATALIA; CONIGLIO, JORGE E.; VAN DEN KERKHOF, ALFONS M.; WEMMER, KLAUS

Congreso; e-CROFI 2021; 2021

Université de Lorraine

Polymetallic quartz veins (Pb-Zn-Cu-Ag ±Au) outcrop in the southern Sierras Pampeanas de Córdoba, Argentina. They are structurally controlled by NNW-striking brittle-ductile transtensional shear zones. Two main episodes of mineralization can be recognized: a first barren episode of milky quartz (Qtz0 and Qtz1), and a second ore-rich episode of grayish quartz (Qtz2), sulfides (pyrite, galena, sphalerite, chalcopyrite and accessory tetrahedrite), Ag-Au tellurides and hematite. Illite from alteration zones reveals K/Ar ages of 329-315 Ma. The primary quartz (Qtz0) shows blue cathodoluminescence (CL), which correlates with high Al contents (up to 3000 ppm) as revealed by EPMA data. Qtz0 is altered and partly replaced by Qtz1 with brown-reddish CL (Fig. 1a) and lower Al (