Cenozoic Tectonics Of The Tuz Golu Basin (Central Anatolian Plateau, Turkey)

Abstract

We present a new 3D geologic model for the architecture and Cenozoic tectonic evolution of the Tuz Golu Basin, a major sedimentary basin in the Central Anatolian orogenic plateau. This model is grounded on 7 depth-converted seismic reflection profiles in combination with the analysis of backstripped subsidence curves, isochore maps, and a palinspastically restored cross-section. Two stages of basin formation are detected during Cenozoic times. During the Palaeogene, around 2 km of basement subsidence led to the development of a sag basin broader than the present basin in the absence of bounding faults. After a period of uplift and erosion, sedimentation restarted by Tortonian times. Up to 3.5 km of post-Palaeogene sediments were deposited in relation to this second regional subsidence phase, which continued possibly well into the Pliocene. During this time, the 2 main fault systems found in the area, the Tuz Golu and the Sultanhani faults, developed as south-west dipping, NW-SE striking, normal faults. At some time in the Late Miocene-Early Pliocene, during regional subsidence, a previously unreported phase of contraction occurred, which led to the development of a north-east-vergent thrust sheet, the culmination of which forms the morphologic ridge to the east of the Tuz Golu Lake. This structure presently divides the previously continuous Tuz Golu Basin. Finally, minor extensional reactivation occurred. At the regional scale, the pre-Late Miocene subsidence is coeval with the initiation of volcanism in the Central Anatolian Volcanic Province and marine carbonate deposition in southern Turkey, and the latest Miocene shortening is (partly) contemporaneous with the onset of uplift in the same region.