Alluvial sedimentology and active tectonics of Güzelbahçe (İzmir)

N-S trending Urla basin has started to form probably during the Plio-Quaternary time. The Plio-Quaternary basin fill was developed on a basement including the Upper Cretaceous?Paleogene rocks of the Bornova flysh zone and the clastic? carbonate sequences of the Miocene volcano-sedimentary successions that were separated by an angular unconformity. The basin fill consists of two different sedimentary units that are separated by an angular unconformity: the Güzelbahçe formation and the young alluvial deposits. The Güzelbahçe formation comprises continental litofacieses such as alluvial fan deposits, stream channel fill deposits and distal/procsimal flood plain deposits, while the young alluvial deposits composed of stream deposits, minor amounts of scree deposits and transitional beach and tidel facies deposits. The Urla basin has been shaped by five different tectonic lines. These are Seferihisar- Yelki Fault Zone (eastern margin fault zone), Demirci ? Ya=c>lar Fault Zone (western margin fault zone), Ku@çular- Urla Fault Zone, Azmak ? Bademler Fault Zone, Ovacık Kocada= Fault Zone (intra basinal fult zones). This study reveal that the Western Anatolia is not only characterized by E-W trending active graben bounding faults, but also, by N-S trending active faults that potentially could create earthquakes. The N- S faults don?t show normal faulting; instead, these are strike?slip faults. Especially the Seferihisar?Yelki Fault Zone will be propagate more than (MW) 6 earthquakes in the future. These tectonic lines could create an eartquake risk for Ezmir and surrounding