Kinematics of a Translational/Rotational Landslide, Central Andes, Northwestern Argentina

ABASCAL, L.; GONZÁLEZ BONORINO, G.,

Environmental & Engineering Geoscience

Año: 2006 vol. 12 p. 369 - 376

A moderately-sized, coherent landslide affected a mountain slope in the Andean foothills of northwestern Argentina in August 2003. The slide sheared through both regolith and Tertiary sedimentary bedrock. Well preserved pluck marks and striations on the scarp walls allowed reconstruction of the slide movement, and deep tension cracks and compressive ridges evidence torsion of the slide block due to friction at the margins and accomodation to underlying topography. The slide event involved, successively, a translational displacement followed by a rotational displacement of the lower portion of the slide mass. Geologic and climatic conditions favor landslide events in the Andean foothills. The risk of future slide events in this region is qualitatively evaluated.