@phdthesis{Arnous2021,
  author    = {Arnous, Ahmad},
  title     = {Paleosismolog{\´i}a y neotect{\´o}nica del antepa{\´i}s fragmentado en el extremo sureste del Sistema Santa B{\´a}rbara, Noroeste Argentino},
  doi       = {10.25932/publishup-53527},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-535274},
  school      = {Universit{\"a}t Potsdam},
  pages     = {182},
  year      = {2021},
  abstract  = {This thesis constitutes a multidisciplinary study of the central sector of the Santa B{\´a}rbara System geological province, the tectonically active broken foreland of the central Andes of north-western Argentina. The study is based on a tectono-geomorphic characterization combined with a variety of geophysical and structural studies. The principal focus was on the faulted piedmont regions of the Sierra de La Candelaria and, to a lesser degree, the extreme south of the intermontane Met{\´a}n basin. The study region is located in the border area between the provinces of Salta and Tucum{\´a}n. The main objective was to characterize and analyze evidence of Quaternary tectonic activity in the region, in order to increase the available information on neotectonic structures and their seismogenic potential. To this end, several methods were applied and integrated, such as the interpretation of seismic reflection lines, the creation of structural sections and kinematic modeling, as well as near-surface geophysical methods, in order to explore the geometry of faults observed at the surface and to assess the behavior of potential blind faults. In a first step, a geomorphic and structural survey of the study area was carried out using LANDSAT and SENTINEL 2 multispectral satellite images, which allowed to recognize different levels of Quaternary alluvial fans and fluvial terraces that are important strain markers in the field. In a second step, different morphometric indexes were determined from digital elevation models (DEM) and combined with field observations; it was possible to identify evidence of tectonic deformation related to four neotectonic faults. In a third step, three structures (Arias, El Quemado and Copo Quile faults) were selected for more detailed studies involving Electrical Resistive Tomography (ERT) and Seismic Refraction Tomography (SRT). This part of the study enabled me to define the geometry of faults at depth, helped to infer geometric and kinematic characteristics, and confirmed the extent of recent deformation. The Arias and El Quemado faults were interpreted as reverse faults related to layer-parallel, flexuralslip faulting, while the Copo Quile fault was interpreted as a blind reverse fault. Subsequently, a joint interpretation of seismic reflection lines and well-logs from the Choromoro and Met{\´a}n basins was carried out, to decipher the principal structures and their influence on the deformation of the different sedimentary units in the intermontane basins. The obtained information was integrated into a kinematic model. This model suggests that the recent deformation is driven by a blind, deep-seated reverse fault, located under the Sierra de La Candelaria and Cantero anticline. The corresponding shortening involves the sedimentary strata of the Salta and Or{\´a}n groups in the adjacent basins, which was accommodated by faults that moved along stratal boundaries, thus bending and folding the Quaternary deposits at the surface. The kinematic model enabled identifying the approximate location of the important detachment horizons that control the overall crustal deformation style in this region. The shallowest detachment horizon is located at 4 km depth and controls deformation in a thin-skinned manner. In addition, the horizon of the thick-skinned style of deformation was identified at 21 km depth. Finally, from the integration of all the results obtained, the seismogenic potential of the faults in the study area was evaluated. The first-order faults that control deformation in the area are responsible for the large earthquakes. While, Quaternary flexural-slip faults affecting only the sedimentary cover are secondary structures that accommodate deformation and were activated very low magnitude earthquakes and/or aseismic movements. In conclusion, the results of this study allow to demonstrate that the regional fault system of intrabasinal faults in the Santa B{\´a}rbara System constitutes a potential seismogenic source in the region, where numerous towns and extensive civilian infrastructure are located. In addition, the derived kinematic model requires the existence of numerous blind structures. Only for a small number of these their presence can be unambiguously detected at the surface by geomorphic analysis, which emphasizes the need of conducting this type of studies in tectonically active regions such as the Santa B{\´a}rbara System.},
  language  = {es}
}