Anatomía de fallas de transferencia entre segmentos de riftnuevos resultados de la Falla de Pamplona (Pirineos Occidentales)

Résumé

The Pyrenean orogen is divided along-strike in segments bounded by traverse structures like the Toulouse, Pamplona or Santander Faults (Tugend et al. 2014). During the Bay of Biscay Cretaceous rifting these faults acted as transference zones of the rift axis and subsequently, during the Alpine inversion, controlled the distribution of synorogenic sedimentary troughs and thrust front emplacement. The Pamplona Fault, in the transfer zone between the western and Basque-Cantabrian Pyre- nees, extends for more than 100 Km from the South Pyrenean Thrust Front in Navarre to the Aquitania Foreland Basin. This study focuses on the southern termination of the Pamplona Fault, marked by a series of aligned salt diapirs, conjugate exten- sional fracturing and absence of significant strike-slip motion (Vergés, 2001; Larrasoaña et al., 2003). The integration of surface geology, seismic surveys and exploration wells in a 3D georeferenced model has allowed a detailed evaluation of the thickness variation of the sedimentary series across the fault zone, the spatial distribution of compressive features, the basal detachment level configuration and the morphology of the underlying basement, whose specific nature is still poorly known.