Artículo de revista
A Neogene giant landslide in Tarapacá, northern Chile: A signal of instability of the westernmost Altiplano and palaeoseismicity effects
Fecha
2008-12Registro en:
Geomorphology, Volume 102, Issues 3-4, 15, Pages 532-541, 2008
0169-555X
Autor
Pinto Lincoñir, Luisa
Hérail, Gérard
Sepúlveda Valenzuela, Sergio
Krop, P.
Institución
Resumen
Giant landslides, which usually have volumes up to several tens of km3, tend to be related to mountainous
reliefs such as fault scarps or thrust fronts. The western flank of the Precordillera in southern Peru and northern
Chile is characterized by the presence of such mega-landslides. A good example is the Latagualla Landslide
(19°15′S), composed of ~5.4 km3 of Miocene ignimbritic rock blocks located next to the Moquella Flexure, a
structure resulting from the propagation of a west-vergent thrust blind fault that borders the Precordillera of
the Central Depression. The landslide mass is very well preserved, allowing reconstitution of its movement and
evolution in three main stages. The geomorphology of the landslide indicates that it preceded the incision of
the present-day valleys during the late Miocene. Given the local geomorphological conditions 8–9 Ma ago
(morphology, slopes and probably a high water table), large-magnitude earthquakes could have provided
destabilization forces enough to cause the landslide. On the other hand, present seismic forces would not be
sufficient to trigger such landslides; therefore the hazard related to them in the region is low.