La Cordillera Béticaun orógeno activo

Abstract

From a seismic and tectonic view, the Betic Cordillera constitutes the most active region of the Iberian Peninsula. This orogen results from the interaction between two main plates (Nubia and Eurasia) together with the Alboran plate, which was individualized and westward displaced by the opening of the Argelo-Provenzal basin. As a consequence of this expulsion, the westward movement of the subduction zone, the origin of the Gibraltar Arc and an oblique collision in southern Iberia were undertaken. During the Tortonian, the opening of the Argelo-Provenzal basin attenuated given rise to a new geodynamic setting which still remains. Thereafter, the compression dominates, accommodated by a strike-slip fault corridor in the eastern sector of the Cordillera, the Eastern Betic Shear Zone, and by regional E-W folds, among other structures, in the central sector. Simultaneously, an extension occurs in the central sector of the Cordillera dimmed by normal NNW-SSE faults. This extension is no longer active in the Alboran Sea, which is currently under compression. In this geodynamic context, the relief of the Betic Cordillera is continuously growing, increasing the surface of the emerged areas, and the average altitude of the orogen with time. The long and complex geological history of the Betic Cordillera is what makes it a significant example for teaching. Students can understan how the tectonic plate map in this region of the planet has substantially changed only in a few million years, and it will go on doing it in the future. In addition, the current debate between the existence of subduction in the Gibraltar Arc and why extension in the central sector of the mountain range occurs in a context of convergence between the main plates of Nubia and Eurasia can be analyzed.