The Iberian Chain is a large intraplate structure raised during the Alpine orogeny. This orogeny, caused by the collision of the Iberian plate with the Eurasian and African plates along the Cenozoic, lead to a compressive stress field that resulted in the uplift of the two main mountain chains in the Iberian Peninsula, the Pyrenees and the Betic System. The Iberian Chain is located between these two major mountain ranges and was formed by the uplift and folding of previously existing mesozic extensional sedimentary basins (tectonic inversion) in the central and eastern region of the Peninsula.

Despite the Iberian Chain is tectonically independent from the Coastal Catalan Range, they do share origin and age. In the linkage or transition zone between both mountain ranges, the NW-SE Iberian Chain and NE-SW Coastal Catalan Range structures interfere. This transition zone extends from the northern area of the Maestrazgo to the south of the Tivissa mountains to the north.

After its uplift, the system changed to be controlled by an extensive regime linked to the opening of the Valencia Trough. The rift system forming the Valencia Trough continues northwards entering the European continent. It began to open in the Miocene and defined the current position of Corsica and Sardinia Islands, as well as the Balearic Islands. Firstly, the dominant extensive stress field was ESE-WNW direction, but currently, the stress field is much complex and multidirectional due to the thermal subsidence phase that currently governs the region.

During this extensional regime, new neogene-quaternary basins appeared. These basins show a significant number of normal faults with evidence of recent activity or even associated instrumental seismicity. The central area basins are characterized by NW-SE to N-S faults; the best examples are the Teruel basin dominated by El Pobo fault system and the Teruel fault, the Calatayud basin bounded by the Vicort, Munébrega and Daroca faults, and the most recent basin of Jiloca, limited to the East by three ‘en-échelon’ normal faults (Calamocha, Sierra Palomera, and Concud).

However, the normal faults in the eastern region of the Iberian Chain are oriented in a NE-SW direction. The best example is the coastal area of the Maestrazgo where many active faults are located, like the Amposta fault system that corresponds to the southwards continuation of the fault system of the Coastal Catalan Range. It is also remarkable the surrounding area of Valencia city where various active faults with associated seismicity are known and controlled by a more complex tectonic regime due to the impact of transpressional forces coming from the Eastern Betic System. The NW-SE to NE-SW Cullera faults stand out within this fault group.

Therefore, the Iberian Chain is an intraplate zone with a moderate degree of deformation, and it is characterized by the presence of active normal faults with orientations ranging from NW-SE to NE-SW and slow movements mostly below 0.1 mm/year.