LATE CENOZOIC EXHUMATION PROCESSES OF MENDERES MASSIF AND RELATED EXTENSIONAL BASIN FORMATION IN WESTERN TURKEY

We present a working hypothesis related to complete exhumation of Menderes massif, and associated extensional basin formation in western Turkey. We propose that the main exhumation of the massif occurred along the north-dipping main breakaway fault that controls the deposition of Upper Oligocene – Lower Miocene basin fill of Kale and Gokova basins. Upward bending of the breakaway fault brings the lower plate rocks to the surface at the beginning of Early Miocene. This dome shaped massif is fragmented by E-W trending grabens. Their tectonic evolution is similar to the rolling hinge model that cause further exhumation of Menderes massif along the bivergent Alasehir and Buyuk Menderes detachment faults. In the latest stage following Pliocene to Quaternary, high angle faults cut up the previous structures. The model presented here explains dominant top to the north northeast sense of shear in the Menderes massif between Lycian nappe front to the south and the Izmir – Ankara suture zone to north. It is an alternative interpretation of recently published apatite – fission track thermochronological results. A north-dipping main breakaway fault has already been suggested under the sea of Crete to explain the core complex structure of Cycladic massif which could be connected by a transfer fault to the our main breakaway, Datça fault in the south of Gokova Gulf. These similarities suggest that Cycladic and Menderes massif might have had a common extensional history following the Oligocene. This model also indicates that Menderes massif is a single metamorphic core complex which record two stages of exhumation.