Cordillera de Los Andes

often used as the name for the mountain range and continental divide of the Chilean-Argentinean Andes between 31° and 39° S lat. in South America.

In the northern part of the Cordillera de los Andes many peaks exceed 5,000-6,000 m (Mount Aconcagua, 6,960 m), but south of 35° latitude none exceed 4,000 m. The range is composed primarily of Mesozoic sedimentary and volcanic rocks with intrusions. South of 33° latitude the western slopes have many active volcanoes, and earthquakes are frequent. As a result of the increasingly great precipitation in the south (200-2,500 mm annually), the snow line drops from 4,900 m at 30° S lat. to 2,300 m at 39° S lat. A desert landscape gives way to a water-eroded and glacial one. In the north the western slopes are covered with drought-resistant scrub; in the central regions, with sclerophyllous forests; and in the south, with humid evergreen forests that extend to the eastern slopes. The eastern slopes are arid as far as 36° S lat. Sometimes the whole western cordillera of the Andes, as well as the section between 20°30’ and 23° S lat. (as far as the volcano Llullaillaco) in the central Andes, is referred to as the Cordillera de los Andes.