The current state of the center-west portion of the Iberian Peninsula is the result of a complex tectonic evolution in which three different phases are distinguished.

The first tectonic phase is compressive and linked to the Hercynian orogeny, origin of the Iberian Massif. This orogeny shows different phases and was active along most parts of the mid and late Paleozoic. Its origin is the collision between the Euroamerican and Gondwana landmasses that ended up with the formation of the Pangea supercontinent.

The second tectonic phase is distensive and active along the Mesozoic. During this phase, the Atlantic Ocean opened, and therefore, the Pangea supercontinent got fractured. In this stage, the Lusitanian Basin was formed and filled with continental and marine sediments that reflect the Atlantic Ocean aperture and show a low deformation degree.

The third tectonic phase is compressive and active along the Cenozoic. It is related to the Alpine orogeny caused by the collision between the Eurasian and the African plate. In this stage, the Central System Mountain Range got slightly reactivated and was the source of the Cenozoic sediments infilling the southern portion of the Duero River basin and the northern area of the Tajo River basin.

Because of this complex tectonic evolution, there are a group of long active faults (lot of them over 100 km long) crossing different Iberian Massif zones. To the west, the NNE-SSW left-lateral strike faults of Manteigas-Vilariça-Bragança (FMVB), Penacova-Regua-Verín (FPRV) and Nazaré-Caldas da Rainha-Vimeiro (FNCRV) (on debate), the NNW-SSE left-lateral strike fault of Porto-Tomar (FPT), and the NE-SW reverse fault of Seis-Lousa (FSL). In the central area, to the south of the Central System Mountain Range, the NE-SW reverse fault of Ponsul (FPO) and the NE-SW left-lateral strike-slip of Plasencia (FPLA). These faults are Paleozoic, but their current movement is linked to their reactivation during the Cenozoic and Quaternary.