Synsedimentary broken-foreland tectonics during the Paleogene in the Andes of NW Argentine: new evidence from regional to centimeter-scale deformation features

CAROLINA MONTERO; M, STRECKER; CECILIA DEL PAPA; ALEJANDRO ARAMAYO; FERNANDO HONGN

BASIN RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016

0950-091X

Unravelingthe spatiotemporal evolution of the Cenozoic Andean (Altiplano-Puna) plateauhas been one of the most intriguing problems of South American geology. Despitea number of investigations the early deformation and uplift history of thisarea has remained largely enigmatic. This paper analyzes the Paleogenetectono-sedimentary history of the Casa Grande Basin, in the present-daytransition zone between the northern sector of the Puna Plateau and the northernpart of the Eastern Cordillera in Argentina. Detailed mapping of synsedimentarystructures has recorded the onset of regional contractional deformation duringthe Middle Eocene, revealing reactivation of Cretaceous extensional structuresand the development of doubly vergent thrusts, as have also been recorded fromother southern parts of the Puna Plateau and the Eastern Cordillera. Theseobservations indicate the existence of an Eocene broken foreland setting withinthe region, characterized by compressional basins and ranges with spatiallydisparate sectors of deformation, that was subsequently subjected to regionaluplift resulting in the attainment of present-day elevations during theNeogene.