The main events characterizing the Mesozoic palaeogeographic evolution of the External Zones of the Betic Cordillera are outlined. The Triassic sediments show a 'germanic' type lacies over the entire region, ending with Late Triassic evaporites and variegated clays of Keuper facies. At the beginning of the Jurassic a transgression takes place, and a broad shallow-marine carbonate-platform environment appears. During the Carixian (180 Ma) the carbonate platform breaks down leading to the differentiation of two large palaeogeographic units: the Prebetic Zone where shallow-water environments prevailed throughout the Mesozoic, and the Subbetic Zone where the sediments are clearly pelagic. Within the Prebetic Zone, two palaeogeographic realms are differentiated: the External Prebetic ,showing important stratigraphic gaps in the Jurassic and Early Cretaceous sequence, and the Internal Prebetic with a thicker and more continuous stratigraphic sequence. Between the Prebetic and Subbetic Zones, a palaeogeographic realm is distinguished (Intermediate units) where turbiditic and pelagic materials were deposited. This zone corresponds approximately to a slope environment during most of Mesozoic times. In the Subbetic Zone a marked differential subsidence occurs during the Jurassic, leading to trough (Median Subbetic) and swells (External and Internal Subbetic). In the Median Subbetic, the deposits consist mainly of marls, pelagic limestones, radiolarites and calcareous turbidites, with mafic volcanic hand subvolcanic rocks. During the Cretaceous pelagic marls and marty limestones were laid down. Mesozoic sedimentation took place along the southern margin of the European plate, in an Atlantic-type continental margin underlain by continental crust. Three-dimensional schemes, explaining the main palaeogcographic events are included.

14 páginas, 8 figuras.

Peer reviewed