Permian-Triassic Rifting Stage

International audience; The Permian-Triassic rifting represents the first of the two Mesozoic rifting stages recorded in the Iberian Peninsula. Its first phases of development started during the Early Permian, and were linked to the beginning of the break-up of Pangea, the large, unique and rheologically unstable supercontinent that mainly resulted from the collision of Gondwana and Laurussia. This chapter analyzes this first rifting stage in Iberia in two separate phases, an initial or tectonic phase, and a later mature phase. This analysis focuses on the main Permian-Triassic basins of the Iberian Peninsula: the Pyrenean, Iberian, Catalan, Ebro and Betic basins, as well as the basins loca…

Seven superimposed lithostratigraphic units have been distinguished in the Upper Trias of Los Pastores (Algeciras). The four lower units (1 to 4) show clayey-sandy-evaporitic Keuper facies. Pollen associations obtained from dark pelitic levels, and bivalves sampled from carbonate intercalations within these four lower units allow to date them as Carnian. These lower units can be correlated with the K1 to K3 units of the Keuper of the Subbetic and of other regions of the Iberian Peninsula. Concerning the three higher units, the unit 6 is pelitic-carbonatic and evaporitic and it also bears Carnian pollen associations. The units 5 and 7, however, are carbonatic and show clearly marine facies a…