Offset archaeological relics in the western part of the Büyük Menderes graben (western Turkey) and their tectonic implications

The Büyük Menderes graben is one of the most important active tectonic structures of western Anatolia. The graben extends for a distance of ∼150 km between the Denizli Basin in the east and the Aegean Sea in the west, where its trend changes to NE-SW. The main active faults are located along the northern margin of the graben, some of which have been reactivated in surface-rupturing earthquakes during the twentieth century and the historical period. Detailed investigations along the NE-SW-trending part of the Büyük Menderes graben showed that archaeological relics have been faulted by surface ruptures during the large historical earthquakes. The ancient city of Priene and an Ottoman bridge are located along the northwestern margin of the graben to the southwest of Söke and in Sazliköy, respectively. Field observations and light detection and ranging (LIDAR) studies at both sites show that faulting has a normal component with considerable right-lateral movement. Offset archaeological features at both Priene and the Ottoman bridge are evidence for the reactivation of the graben boundary faults in the past 2000 yr. At Priene, a N-S-trending street wall is offset by 21 cm vertically and 10 cm dextrally, the eastern wall of the gymnasium is offset by 8 cm vertically, and the floor blocks of the agora are displaced by 26 cm vertically and 13 cm dextrally. The Ottoman bridge displays 76 cm vertical and 43 cm dextral offset to the southeast, which probably occurred during the 1846 earthquake. © 2010 The Geological Society of America. All rights reserved.