the part of the Andes that lies between 15° and 28° S lat. in Peru, Bolivia, Chile, and Argentina. It attains a maximum width of 750 km. The central part is occupied by the Puna de Atacama, an interior high plateau with elevations of 3,700–4,100 m and separate ridges rising to 6,000 m, and by the Altiplano, a depressed level plain. On the east the Puna is framed by massifs of the Cordillera Central, which soar to a height of 6,550 m in the Cordillera Real. On the west, extinct and active (Misti, Llullaillaco) volcanoes of the Cordillera Occidental rise to more than 6,800 m; the highest peak is Mount Ojos del Salado (6,880 m). Volcanic material covers the western and southern parts of the Central Andes. Mineral resources include major deposits of tin ore at Potosí and Llallagua, tungsten and antimony at Caracoles, and copper at Chuquicamata and El Salvador, as well as bismuth, silver, iron, and complex ores.
The region has a tropical high-mountain climate. On the windward eastern slopes, receiving 1,000–3,000 mm of precipitation a year, the climate is humid. The Puna and the western regions have a markedly continental climate. Mean monthly temperatures in the Puna vary from 4°C to 8°–10°C. The annual precipitation in the Puna ranges from 500–600 mm in the northeast to less than 100 mm in the southwest and west. The region is subject to high winds. The Central Andes have the world’s highest snow line, which rises from 4,850 m in the east to 6,500 m in the interior. Whereas the eastern slopes are cut by the canyons of numerous rivers, only intermittent streams flow in the west. The Puna is an interior drainage area, with most of the runoff entering Lake Titicaca and Lake Poopó. The region has many salt flats, called salares (Coipasa, Uyuni, and Atacama). The high-mountain steppes in the northern and northeastern Puna afford pasture for livestock. Grain crops and potatoes are cultivated to an elevation of 4,000 m. In the west and south there are semideserts and deserts. Moderately humid tropical mountain forests cover the eastern slopes.
E. N. LUKASHOVA