Géologie des volcans quaternaires des Nevados de Chillán (Chili)

The Nevados de Chillán are located in the Southern Chilean Andean Cordilleras (71°25′ W, 36°50′ S). Their historic activity is retraced since 1750. The quaternary volcanoes are located along the major axis of an old elliptic caldera. The recent lavas of the Nevados de Chillán are andesites and dacites characteristic of cale-alkaline association which is classical for orogenic beits. Their K₂O content has been correlated with the depth of the Benioff zone in the frame of the quaternary volcanism of the Chilean continental margin.