Zona de transferencia en el sector occidental del Pirineo Central, ejemplo de la falla de Oroz-Betelu-Unzué. Zona surpirenaica. Navarra

Abstract

Based on structural, stratigraphic and gravimetric data, a regional scale N 020-040 E blind-fault, named the Oroz-Betelu- Unzue fault, extending from the western part of the Oroz-Betelu massif to the Sierra de Alaiz thrust front, is inferred. This fault would have acted as a transfer extensional structure during Early Cretaceous times and later, during the Alpine compression, the different stratigraphic and structural characteristics of the fault-blocks would have favoured the formation of major differences between the contractional structures occurring in the blocks of the Oroz-Betelu-Unzúe fault-zone. The Alaiz thrust sheet and adjacent areas represents a good example of the structural changes related to the Tertiary evolution of Oroz-Betelu-Unzué transfer zone