LANDSCAPE RESPONSE TO STRIKE-SLIP FAULTING LINKED TO COLLISIONAL SETTINGS - QUATERNARY TECTONICS AND BASIN FORMATION IN THE EASTERN BETICS, SOUTHEASTERN SPAIN

Neotectonic behaviour of the Eastern Betics (southeastern Spain) has been controlled by the presence of a large, left-lateral shear zone. This is an intraplate transcurrent zone, probably decoupled by a mid-crustal detachment horizon. The morphological expression of this crustal structure is a sigmoidal corridor in which the main Quaternary basins are located. Three types of morphostructural domains can be distinguished in the sigmoidal corridor: the central segment, and the northern and southern terminal splays. The central segment is characterized by wrench tectonics, whilst the southern and northern terminal splays are controlled by transtensional and transpressional tectonics, respectively. The Quaternary morphostructural pattern is only the more recent picture of the tectonic processes that have controlled the late orogenic evolution of the Eastern Betics: the indentation of the Aguilas arc, accompanied by thin-skinned thrusting and tectonic escape in its easternmost sector; and extensional collapse, accompanied by thin-skinned stretching, in its westernmost sector.