Geometría y cinemática del diapiro de Poza de la Sal (Pirineos Vasco-Cantábricos)

espanolEl Diapiro de Poza de la Sal es una de las estructuras salinas mas meridionales que presenta la Cuenca Vasco-Cantabrica. Esta cuenca se desarrollo en relacion a la apertura del Golfo de Vizcaya durante el Mesozoico y se invirtio contractivamente durante la orogenia Alpina. Los materiales evaporiticos del Triasico Superior jugaron un papel muy destacado durante ambas etapas de deformacion, favoreciendo el desarrollo de la tectonica salina en la etapa extensiva y actuando de nivel de despegue durante la etapa compresiva. El presente trabajo pretende caracterizar las geometrias y relaciones estructurales de los materiales del encajante para comprender la evolucion de dicha estructura. Asi, concluimos que la estructura diapirica observada en la actualidad es tardia (el diapiro perforo durante el Mioceno tardio). Hasta ese momento, la estructura salina paso por diferentes fases, iniciandose como un anticlinal salino en el Cretacico, el cual fue rejuvenecido durante la compresion (Oligoceno-Mioceno). EnglishThe Poza de la Sal Diapir is one of the southernmost salt structures situated in the BasqueCantabrian Basin. This basin developed during the Mesozoic extension and was later inverted, during the Alpine compression. The Upper Triassic evaporites played an important role during both the extensional and compressive phases triggering salt tectonics and forming a preferential detachment level. This work aims at characterizing the geometry and structural relationships of the diapir overburden to understand the evolution of the Poza de la Sal Diapir. To do that, we made a detailed geological map and a crosssection, based on field data and supported with the available subsurface data, which are presented here. The observed data led us to conclude that the structure started growing during the Mesozoic extensional phase, when an early anticline or pillow developed. Later, during the compressive phase it was folded (during Oligocene times and mostly during Miocene times), generating growth-strata deposits. Finally, the diapir continued rising until cropping out to the topographic surface.