Magmatic U-Pb zircon ages west of the Domeyko Fault System, Collahuasi District (Chile): implications for its potential westward continuity

Abstract

This study presents new high-precision U-Pb zircon age data to document previously unrecognized igneous bodies in a poorly explored sector in the western part of the Collahuasi District, northern Chile. By integrating these new geochronological constraints with detailed geological mapping, petrography, and mineralogical observations, the temporal and spatial patterns of magmatism west of the Domeyko Fault System, the most relevant tectonic structure in the zone, are refined. These patterns reveal multiple magmatic episodes ranging in age from the Permian to the Eocene, some temporally consistent with the Paleocene-early Eocene and late Eocene-early Oligocene metallogenic belts of northern Chile. Of these, the younger event hosts the principal porphyry Cu-Mo deposits of the Collahuasi District, whose distribution is spatially associated with major structures of the Domeyko Fault System.