Neotectonic Activity Of Eskişehir Fault Zone In Vicinity of İnönü-Dodurga Area

Abstract

The Eskişehir fault zone which forms the north-northeastern boundary of the Western Anatolian extensional region is situated between the İnegöl fault in the west and the Tuz Gölü fault in the east. Many earthquakes with magnitudes ≥4 have occurred on the Eskişehir fault zone. Of these, the 20 February 1956 Eskişehir (Çukurhisar) earthquake (M=6.4) is the largest event recorded on this fault zone. On the other hand, no remarkable earthquake activity has been recorded in historical and instrumental period on the İnönü – Dodurga segment which is known to be active according to its morphological features and GPS measurements. The İnönü – Dodurga segment is an oblique fault with right-lateral strike-slip component and extends in WNWESE and E-W directions along a sharp morphologic lineation. The İnönü – Dodurga fault causes the termination of the NW-SE striking right-lateral strike-slip faults situated to the south of the fault at the boundary of the İnönü basin. Resistivity data show the presence of faults bounding the basin in the north and in the south as well as buried faults. Hanging valleys are situated along the southern margin of the İnönü – Dodurga segment. The earthquake records on the Eskişehir fault zone, geophysical data and the presence of the hanging valleys indicate that the İnönü – Dodurga segment is active and plays an important role in the evolution of the recent morphology.