High Quality Content by WIKIPEDIA articles! The Geology of Chile is mainly a product of the Andean and preceding orogenies which are caused by the long-lived convergent boundary at South America`s western coast. While in the Paleozoic and Precambrian this boundary was affected by the accretion of terranes and microcontinents it has since then developed into a pure subduction zone. The subduction have shaped four features parallel to its strike; the Andes, the Intermediate Depression which is a graben and foreland basin, the Coast Range which is an accretionary wedge and horst and the Peru-Chile Trench off the coast. As Chile lies in an active continental margin, it host a large number of subduction volcanoes and nearly all of the territory of Chile is subject to earthquakes arising from strains in the subducting Nazca and Antarctic Plates or shallow strike-slip faults.