Flysch siliciclástico y flysch carbonatado en el relleno del graben cretácico de Latsaga («Depresión Intermedia», Navarra)

Abstract

The "Central Depression" was a narrow deep marine basin located in northern Navarre (western Pyrenees), mainly filled with Upper Cretaceous calcareous flysch and inverted during Alpine Orogeny. The base of this basin in the Latsaga area is a 3 km wide graben, bounded by NNE-SSW synsedimentary faults and created during late Albian times. The first fill of the graben was a late Albian siliciclastic flysch. This was deeply eroded during latest Albian-middle Cenomanian time interval, so that a major submarine canyon was created. The fill of this trough was made with heterolithic parabreccias and calcareous turbidites first, and with calcareous turbidites and less parabreccias later on. The graben was finally fossilized with the same calcareous flysch during the Late Cretaceous. The proximity of the graben to the E-W Leitza major fault, which bounds the southern margin of the "Central Depression" 3 km to the south of Latsaga, allows to interprete this graben as a pull-apart basin related to Cretaceous movements of the Leitza fault