The active fault pattern based on morphotectonic and structural data in the south of Ulubat Lake and the Susurluk valley along the southern branch of North Anatolian Fault Zone: A criticism of the bend model in northwest Anatolia

Abstract

Field observations and morphotectonic evaluations on the south of Ulubat Lake and the Susurluk valley show that the dominant active fault pattern consists of northeast-southwest and east northeast-west southwest right-lateral faults and northwestsoutheast normal faults developing between these strike-slip faults. We redefined the active faults in the south of Ulubat Lake and discovered that these northeast-southwest right-lateral faults control the route of Susurluk River. Based on these discoveries and evaluations, we can claim that the “bend model” previously proposed for the region is not valid, as seen in the Mustafakemalpaşa Fault and Balıkesir-Kepsut Fault examples. Instead, we suggest that the faults belonging to the southern branch of the North Anatolian Fault Zone extend to Akhisar and İzmir via Bursa, Susurluk, and Balıkesir.