HR: 11:45h
AN: U52A-06    [Abstracts]
TI: Thrusting Evolution in the Southern Cordillera Oriental (Northern Argentine Andes)
AU: * Carrera, N
EM: nuriacarrera@ub.edu
AF: Departament de Geodinàmica i Geofísica, Universitat de Barcelona, Marti i Franques s/n, Barcelona, 08028, Spain
AU: Munoz, J
AF: Departament de Geodinàmica i Geofísica, Universitat de Barcelona, Marti i Franques s/n, Barcelona, 08028, Spain
AB: Growth strata and unconformities observed in the Neogene-Quaternary synorogenic sediments in the southern Cordillera Oriental of northern Argentine Andes demonstrate that deformation migrated eastwards from the Puna to the Santa Bárbara system, as it is accepted and well documented. However, the newly described growth sequences and unconformities allow us to unravel a more precise timing of the structures and determining the partitioning of the deformation through time into the thrust and fold wedge. Thrust evolution was mostly controlled by the reactivation of earlier extensional faults of the Salta Rift Basin. The geometry of the inverted structures combined with the general forward migration of the deformation, resulted in different thrust sequences. The foreland dipping imbricate stack of the western Cordillera Oriental developed forwards during Middle-Upper Miocene, giving rise to a break back thrusting sequence. Thrust propagation rate increased at Upper Miocene- Lower Pliocene times when the eastern part of the Cordillera Oriental developed. At that time a widespread deformation and synchronous thrusting occurred in the Cordillera Oriental. Afterwards, deformation was mostly restricted in the eastern part of the Cordillera Oriental. Finally, during the Quaternary deformation involved a wider zone, including all the Cordillera Oriental and the Santa Barbara System, leading to the reactivation of previously developed thrusts.
DE: 8102 Continental contractional orogenic belts and inversion tectonics
DE: 8108 Continental tectonics: compressional
DE: 8175 Tectonics and landscape evolution
SC: Union [U]
MN: 2007 Joint Assembly