Layout and alluvial deposits of the Middle Guadalquivir River and its tectonic implications (Córdoba and Jaén)

Abstract

The Middle Guadalquivir River flows along the contact between the Iberian Massif and the Miocene infill of the Guadalquivir basin. The fluvial channel has a meandering pattern, with alternation of bedrock stretches, where the fluvial channel entrenches into the Iberian Massif rocks, and alluvial stretches, where the river deposits sediments over the soft Miocene materials. Since the Pliocene, the river has deposited alluvium that constitute a system of terraces, the highest ones located south of the current channel. The location of these latter terraces and their local tilting indicate the entrenchment and northward migration of the river through the northern fringe of the Guadalquivir basin. Conversely, north of the river, the Campo Fértil abandoned meander and other fluvial geomorphological features indicate southward tilting of the southern edge of Sierra Morena. Such opposite tilting may be explained by differential uplift of the hercinian basement in southern Sierra Morena combined with the northward migration of the betic orogenic wedge, due to both the flexural bending of the betic foreland and the intraplate propagation of the betic deformation front.