Geochemistry, petrogenesis and tectonic significance of the volcanic rocks of the Las Tortolas Formation, Coastal Cordillera, northern Chile

The Las Tórtolas Formation extends from 29° to 26° S along the northern chilean coast and has been interpreted as a Carboniferous accretionary prism. This essentially metasedimentary turbiditic formation constituted the late Paleozoic basement of the Upper Triassic-Jurassic magmatism during the inception of the Andean cycle in northern Chile. The geochemical characteristics and field relations studied in the volcanic rocks of the Las Tórtolas Formation, described with detail in this work, mean a key fact to assess the notable paleogeographic changes occurred during the pre-Andean cycle in the western margin of South America.