 Off the western coast of South America, the Nazca Plate subducts beneath the South America Plate at a rate of .This subduction process is responsible for volcanism in the Central Volcanic Zone and started during the Jurassic period after the opening of the southern Atlantic Ocean, which triggered the onset of subduction of the Nazca Plate.Volcanic arc-associated volcanism originally occurred within the Cordillera de la Costa in the Jurassic, but later it migrated resulting in the emplacement of the Tacaza and Toquepala groups and finally the Neogene Barroso group.