Morphotectonic analysis of the jujuy valley – NW Argentina

Piedmonts configure one of the most dynamic morphotectonic environments where, in a span of a couple of hundreds of thousands of years, new ranges can emerge by tectonics and be severely washed out by erosive processes. Within this context, the valley of Jujuy, in northwest of Argentina, is marked by the occurrence of the Sierra de Los Alisos (SLA), a complex anticline generated by a thin-skinned fault, which controls the landscape of the valley, its hydrographic network, and the pattern of sedimentation. This research employed morphometric tools and drainage patterns to understand how the evolution of the SLA shapes the valley landscape, which allowed to recognize the structural control in the alluvial deposits adjacent to it. With the combined employment of distribution of knickpoints, asymmetry factor analysis, catchment segmentation, and remote sensing cartography it was possible to recognize that influence of the Los Alisos thrust in the landscape is higher than expected. Its influence is also recognizable in the buried portion of the morphostructure, between the SLA and the Cordillera de Zapla, and not just in the frontal portion, uplifted by the fault propagation fold.