Genesis of the Picachos Cu-(Ag) manto-type deposit, North-Central Chile: a multidisciplinary approach

Abstract

The Coastal Cordillera of Northern Chile hosts numerous volcanic/sedimentary-hosted stratabound copper deposits termed “manto-type”, forming an economically important cupriferous metallogenic belt in Chile that represents the third largest source of copper of the country (Maureira et al., 2023 and references therein). Two groups of stratabound Cu-(Ag) deposits occur parallel to the Coastal Cordillera (Fig 1A): 1) hosted by the Jurassic volcanic and volcaniclastic sequence of La Negra Formation (e.g., Mantos Blancos, Michilla, Las Luces), and 2) hosted by Lower Cretaceous volcanic and volcano-sedimentary units such as Lo Prado, Veta Negra, Quebrada Marquesa and Arqueros Formations (e.g., El Soldado, Talcuna, Uchumi, Lo Aguirre). Here, a multidisciplinary approach to unravel the genesis of the Picachos deposit has been performed. It includes core logging, petrography, SEM-EDS, EMPA (sulfides), whole-rock geochemistry, Raman spectroscopy (minerals and carbonaceous material) and, stable and radiogenic isotope (sulfides, carbonates) studies.