complex volcano
A complex volcano, also called a compound volcano or a volcanic complex, is a mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock. They may form due to changes in eruptive habit or in t ...
on the northern part border between
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
and
Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
. It consists of four overlapping stratovolcanoes along a north–south line. The main volcano face 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
Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyol ...
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.