Dataciones (U-Th)/He en apatito en la región de Altar (31º30´) Cordillera Principal de San Juan: relación entre exhumación tectónica y emplazamiento de los cuerpos subvolcánicos

Abstract

In this study, we present new apatite (U-Th)/He (AHe) thermochronology ages for the Main Cordillera of San Juan (31°30?S), Argentina, in the area of the porphyry Cu-(Au) Altar deposit. Samples corresponding to the late Carboniferous tonalite (~ 297 Ma) that forms part of the basement of the study area showed U-Th / He ages in apatitesbetween 14.3 and 11.87 Ma. U-Th/He data in apatites from the middle to late Miocene subvolcanic stocks showed ages between 13.45 and 11.17 Ma. U-Th/He ages in apatites between 14.3 and 11.17 Ma reflect a pulse of exhumation of the region during the middle Miocene. The data obtained suggest that the intrusion of the subvolcanic bodies in the study area (between 12-11.3 Ma) was contemporaneous with the regional exhumation event.