Abstract

LEBINSON, Fernando et al. Geometría y cinemática de las estructuras tectónicas en el extremo septentrional de la faja corrida y plegada del Agrio, Cuenca Neuquina. Rev. Asoc. Geol. Argent. [online]. 2015, vol.72, n.3, pp.299-313. ISSN 0004-4822.

The northern end of the Agrio fold and thrust belt is known for its different styles of fault-related folds formed by the interaction of thick and thin-skinned structures. In the western sector of the study area, it was found a kilometer scale anticline that has the oldest sedimentary rocks of the Cuyo Group (Early-Middle Jurassic) in its core. In this way, the participation in depth of the basement was inferred in the deformation. In the eastern sector, folds were identified with a shorter wavelength associated with faults mainly detached in the Auquilco Formation and along secondary levels such as the Vaca Muerta, Agrio and Huitrín formations. In the Truquico stream area, there is a triangular zone originated by anticlines with opposite vergence. They are related to thin-skinned structures, where folded synorogenic deposits of possible Miocene age were surveyed. A balanced cross-section was constructed at 37°27' S in order to interpret the structural style of the region characterized by basement wedges developed as fault-bend folds. It propagates into the evaporites of the Auquilco Formation transmitting the deformation toward the foreland and generating thin-skinned structures. The restoration of the interpreted structural cross-section allows to estimate a tectonic shortening of 13.1 km (22.6%).

Keywords : Basement wedges; Thin-skinned structures; Andean deformation; Balanced cross-section.