Tectosedimentary phases along the Leitza Fault and their relation to Cretaceous Iberia/Europe plate boundary evolution

Abstract

The tectosedimentary study of the Central Depression in the Basque-Cantabrian Basin (Western Pyrenees, Spain) has yielded the characterization and evolution of different marine depositional systems during Aptian to Coniacian times. At that time, carbonate platform to siliciclastic basin marine depositional systems were transgressively arranged onlapping the Bortziri-Cinco Villas Paleozoic Massif. The onset and evolution of sedimentary depositional systems were controlled by strong sinsedimentary tectonic activity. The study of sinsedimentary tectonic structures and its effects in sedimentary systems has permitted the characterization of 5 tectosedimetary phases related to the formation of a fault-bend type strike-slip basin along the Leitza Fault during Late Aptian to Coniacian times. The observed tectosedimentary features indicate a regional sinistral transtensional strain during all the tectosedimentary phases, except for the Phase IV when transpressional features are recognized, and permit to relate them to sinistral strike-slip movements along the Leitza Fault.