A series of 6-1 million years old andesitic to dacitic stratovolcanoes make up the Cordillera de San Buenaventura, and Quaternary basaltic volcanoes are dispersed over the wider region. In the surroundings of Cerro Blanco lies the Cueros de Purulla volcano north and the Nevado Tres Cruces-El Solo-Ojos del Salado complex farther west.