Coastal neotectonics in Southern Central Andes: uplift and deformation of marine terraces in Northern Chile (27°S)
Résumé
Neotectonic observations allow a new interpretation of the recent tectonic behaviour of the outer fore arc in the Caldera area, northern Chile (27°S). Two periods of deformation are distinguished, based on large-scale Neogene to Quaternary features of the westernmost part of the Coastal Cordillera: Late Miocene to Early Pliocene deformations, characterized by a weak NE SW to E W extension is followed by uppermost Pliocene NW SE to E W compression. The Middle Pleistocene to Recent time is characterized by vertical uplift and NW SE extension. These deformations provide clear indications of the occurrence of moderate to large earthquakes. Microseismic observations, however, indicate a lack of shallow crustal seismicity in coastal zone. We propose that both long-term brittle deformation and uplift are linked to the subduction seismic cycle.