Island arc volcanism, volcanic arcs

Abstract

Terrestrial island arcs or volcanic arcs are regions up to 100 km wide of subaerial and submarine volcanoes whose trenchward limit is ~120 km above the subducting plate. Their magmas are more andesitic than elsewhere on Earth or other planets and contribute to continent formation. Their volcanoes are often explosive, and their magmatism creates important metal ore deposits. There are 3-D variations in the spacing of volcanoes and the composition of magmas both of which are related to the thermal structure of the subducting plate and overlying convecting mantle.