Early Cretaceous flysch from Betic-Maghrebian and Europe Alpine Chains (Gibraltar Strait to the Balkans): comparison and palaeotectonic implications

Abstract

Early Cretaceous flysch crops out along all the Alpine Chains of the western, central and eastern Europe for more than 7000 km from the Gibraltar Arc to the Balkans. In the different sectors of the Alpine Chain (Maghrebides, Apennines, Alps, Dinarides, Hellenides, Carpathians and Balkans) these flysch deposits, characterized by calcareous turbidites grading upwards into arenaceous turbidites, mark the contact between the internal and external areas. They show a provenance linked to internal areas and are made up by crystalline sources and locally by ophiolitic complexes. Due to the Cretaceous re-organization of the plates, all these successions experienced a Late Cretaceous tectonics, with the only exception of the Maghrebian flysch deposits. In this area, similar tectonic events have never been recorded but only suspected and aged to slightly later times. This paper aims to show the stratigraphic, geological and structural similarities of all these Early Cretaceous flysch sediments by emphasizing the difficulties to imagine that only the Maghrebian sector of the Alpine Tethys escaped the Mid- to Late-Cretaceous tectonics widely recognized in all the other segments of the Alpine Chain. In fact the Late Cretaceous or post-Cretaceous tectonics connected with a “mesoalpine” stage, has been hypothesized for the Maghrebian chain at the beginning of the nineties and recently it has been supported by the presence of Alpine metamorphic overprints recognized within the Hercynian crystalline units of the Calabria- Peloritani Arc (southern Italy). This tectonics seems to be linked to an early segmentation and deformation of the Maghrebian Early Cretaceous flysch with local underthrusting beneath the southern European margin.