The Dead Sea Fault and related subsurface structures, Gaziantep Basin, southeast Turkey

Late Cretaceous and Miocene collisions of the Arabian, Anatolian and Eurasi an plates, as shown by widespread ophiolitic exposures along the suture, cr eated favourable geological conditions for the formation of the surface and subsurface structures in the Gaziantep Basin, southeast Turkey. The late C retaceous (Maastrichtian) emplacement of the Kocali-Karadut ophiolite compl ex induced subsidence in the northwestern zone of the Kastel Basin during t he early Alpine Orogeny and influenced the structural evolution of the fore land area. The Dead Sea Fault, which originated in the Red Sea in Miocene t ime, propagated towards the northwest in the Suez Gulf and the north-northe ast in southeast Turkey, and influenced the structural evolution of the Gaz iantep Basin. These two major tectonic events produced many thrusts, thrust -related subsurface and surface anticlines, faults, fractures, flower struc tures and basaltic flows in the area. Geological and geophysical investigat ions indicate the existence of two important structural phases. The older s tructures were formed during the late Cretaceous movements, but they have b een reactivated by latest Miocene tectonic activities with appearance of th e Strands of the Dead Sea Fault in the sedimentary basin. The geothermal st udies show also that, as a result of the Tertiary transgressions and volcan ic activity, the northern and southern sectors of the Gaziantep Basin under went differing subsidence and structural histories.