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 b een controlled by the presence of a large, left-lateral shear zone. Th is is an intraplate transcurrent zone, probably decoupled by a mid-cru stal 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 distinguis hed in the sigmoidal corridor: the central segment, and the northern a nd southern terminal splays. The central segment is characterized by w rench tectonics, whilst the southern and northern terminal splays are controlled by transtensional and transpressional tectonics, respective ly. The Quaternary morphostructural pattern is only the more recent pi cture 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 easte rnmost sector; and extensional collapse, accompanied by thin-skinned s tretching, in its westernmost sector.