Cover Image

The top panel is a 3D view of a sector of the volcanic plateau developed in the transition between the Central and Patagonian Andes where large scale tectonic-related rockslides occurred. UTM coordinates (UTM zone 19S). The bottom panel is a view to the south of the volcanic plateau. MA, Moncol anticline; ChaF, Chacayco fault; GF, Guañacos fault; and ChF, Chochoy Mallín fault. 1, Guañacos rotational slide I; 2, Guañacos rotational slide II; 3, Cerro Guañacos rock avalanche; 4, Piche Moncol rock avalanche; 5, Cerro Moncol rock avalanche; 6, Chacayco rock avalanche; 7, Chacayco rotational slide; 8, Chochoy Mallín rock avalanche; 9, Ñireco topple; 10, Lauquén Mallín rotational slide; 11, La Negra rock avalanche; and 12, Picún Leo rock avalanche.

Rockslides estimated between ~31 to 5 ka caused significant hillslope erosion, at a rate of 0.318 km³/ka, and created seven dams. Around 95 percent of the total rock volume involved in rockslides still remains in the depositional area. Despite their capacity to remove large amounts of rock from hillslopes, by creating dams, they have graded fluvial courses to local base levels, interrupted the sediment flux cycle and trapped significant amounts of sediments. (See article titled Effects of tectonic deformation and landslides in the erosion of a mountain plateau in the transitional zone between the Central and Patagonian Andes; Penna and others, this issue, p. 257–274).