Cerro Bayo is a complex volcano on the northern part border between Argentina and Chile. It consists of four overlapping stratovolcanoes along a north–south line. The main volcano fauce is located on the Argentine side, thought the summit of the complex is just west of the border, in Chile. The volcano is about 800,000 years old, but it is associated with ongoing ground uplift encompassing also the more northerly Lastarria and Cordón del Azufre volcanoes. The high summit is the source of two viscous dacitic lava flows with prominent levees that traveled to the north. In 2007 a steam eruption were observed by researchers investigating nearby salt pans such as Salar Ignorado. See also List of volcanoes in Chile List of volcanoes in Argentina List of mountains in the Andes Los Colorados (caldera) References (in Spanish; also includes volcanoes of Argentina, Bolivia, and Peru) Complex volcanoes Volcanoes of Atacama Region Volcanoes of Catamarca Province Mountains of Argentina Mountains of Chile Polygenetic volcanoes Subduction volcanoes Argentina–Chile border International mountains of South America Five-thousanders of the Andes