What is "arequipa-antofalla"

Arequipa-Antofalla is a basement unit underlying the central Andes in northwestern Argentina, western Bolivia, northern Chile and southern Peru. Geologically it corresponds to a craton, terrane or block of continental crust. Arequipa-Antofalla collided and amalgamated with the Amazonian craton about 1000 Ma ago during the Sunsás orogeny. As a terrane Arequipa-Antofalla was ribbon-shaped during the Paleozoic, a time when it was bounded by the west by the Iapetus Ocean and by the east by the Puncoviscana Ocean.