Permian and Triassic
The Permo-Triassic succession in Spain records the change from a Pangaea configuration and compressive tectonic regime inherited from the Variscan orogeny, to an exten-sional tectonic setting accompanied by continental break-up and westward expansion of the Neotethyan ocean (Fig. 10.1). During latest Carboniferous–Early Permian times, latest Variscan orogenic extension associated with andesitic volcan-ism produced small continental basins in the Pyrenees, the east and central Iberian Ranges, and along the southern margin of the Iberian Massif. Extension continued into and during Late Permian times, creating half-graben and graben continental sedimentary basins bounded by Palaeozoic highs. Subsequent westward expansion of Neotethys led to successive marine transgression–regression cycles along the eastern and southern margins of the Iberian plate, which drowned the Palaeozoic highs during Middle Triassic (Ladinian) times. Although the Atlantic Ocean did not open during Triassic times, slow subsidence allowed the Neotethys to prograde westwards around the Iberian Massif, so that the Pyrenean-Cantabrian, Betic and Lusitanian basins became interconnected and extended towards the Grand Banks area (Fig. 10.1; Jansa et al. 1980).
Permo-Triassic southward propagation of pre-existing Norwegian-Greenland sea rift systems and westward propagation of the Tethys rift system represented the initial phase of post-Variscan plate reorganization, spanning some 90 Ma (Fig. 10.1a). The development of different rift systems during this initial break-up of Pangaea was related to a series of strike-slip faults that dissected the Variscan foldbelt and its associated foreland areas. The development of the different rift systems of central and western Europe