Coastal neotectonics in Southern Central Andes: uplift and deformation of marine terraces in Northern Chile (27 degrees S)

摘要

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. (C) 2004 Elsevier B.V. All rights reserved.