The Charrarruca porphyry-type alteration zone: New evidence of mineralizing Late Cretaceous-Eocene magmatism in the Southern Central Andes of Argentina

Abstract

The Charrarruca porphyry-type alteration zone is located in the northern part of the Andacollo Mining District (AMD), placed in the northern Neuquén Precordillera, (Argentina). Potassic, chloritic-carbonatic, sericitic, and propylitic alteration halo of ∼1.5 km2 affects an andesitic/dacitic subvolcanic body. These rocks, with arc affinity and Upper Cretaceous-Paleogene age (65 ± 2.5 Ma), derived from a magma evolved under normal crust thickness conditions, allowing the correlation with the intrusive facies of the Naunauco Group. The petrogenetic characteristics of these rocks attest to indications of the fertility of this magmatism, turning into a prospective guide for the unexplored Upper Cretaceous–Eocene Neuquén porphyry copper metallogenic belt.