Geology of Chile the Taitao Peninsula, the Peru–Chile Trench subduction zone is the boundary between the South American and Nazca Plates. At Taitao, the Chile Triple Junction and the Nazca Plate subduct the South American Plate. In Norte Grande the mountains form a series of plateaus, such as Puna de Atacama and the Altiplano. At a south latitude of 27 degrees, Chile's highest mountain (Ojos del Salado) reaches a height of . Below 42 degrees south, the Andes split into a fjord landscape and the highest mountain is Monte San Lorenzo at . As the mountains ebb, the snow line lowers; in the
Khibiny Mountains about 1,300 km. and occupies the central part of the peninsula at a relative elevation of 900–1000 m above the surrounding plain. The mountains are not particularly high; the two highest peaks are the Yudychvumchorr, which stands , and the Chasnachorr, which stands . The average elevation is . The mountains form the shape of a horseshoe topped by a high plateau, drained by a series of deep canyons. The peaks are of plateau type, with steep slopes, with glaciers, icefields and snowfields in some places. The overall terrain is alpine tundra. The second, and similar mountain range of the