NEOTECTONICS OF NORTH CENTRAL ANATOLIA: A STRIKE-SLIP INDUCED COMPRESSIONAL REGIME

North Central Anatolia is mainly dominated by strike-slip tectonics. Right lateral the North Anatolian (NAFZ), the Kırıkkale-Erbaa (KEFZ), and the Eskisehir Fault Zones (EFZ) are major strike-slip neotectonic elements in the region. The triangle shaped area bounded with these fault zones has many contractional structures such as tectonic wedges, folds, and blind thrusts.

The Eldivan-Elmadag Pinched Crustal Wedge (EPCW), having a thrusted eastern and normal faulted western margin and composed of the Neo-Tethyan suture zone rocks, is a main NNE-trending contractional structure in the area between the NAFZ and the KEFZ. The EPCW has been active since Late Pliocene as indicated by the age of the syn-tectonic Deyim formation and the seismic activity. The other NNE-trending wedge structure called Abdusselam Wedge (ASLW), having a thrusted eastern and normal faulted western margin similar to the EPCW, is located between Ayas and Kazan in west of Ankara. The ASLW deforms the Middle Miocene-Pliocene sedimentary rocks. The normal faults on the western margin of the ASLW create drag fold synclines whereas on the eastern side thrusts and blind thrusts produce a NNE-trending large-scale folding. Apart from these major wedges, asymmetrical folding on the Oligocene sedimentary units probably created by the NNE-trending blind thrusts is seen at the east of the EPCW around Bagdatli. All these contractional structures are limited by the regional strike-slip faults namely the NAFZ, KEFZ and EFZ. They are compatible with the recent GPS based regional geodetic strain analyses and microseismic activity which indicate active NW-SE compressional regime in North Central Anatolia.