Türkiye Jeoloji Bülteni

Late Cenozoic Stress States along the Ganos Fault, NW Turkey

Abstract: The Ganos Fault, has a big earthquake (Ms:7.3 in 1912), as a right-lateral strike-slip fault, a segmentof the northern strand of the North Anatolian Fault is elongated a N70°E trend in west of the MarmaraSea between Gaziköy (Tekirdağ) and Saros Gulf. This study reveals at late Cenozoic stress states by thefault kinematic analysis, inversion of the earthqukes focal mechanism and remote sensing studies alongthe Ganos Fault. Result of the kinematics analysis was carried out a main tectonic regime.. First mainlystrike-slip faulting developed under NW-SE trending compressional direction showing by a (σ1) 130°±16°and a (σ3) 53°±13° trends and Rm ration calculated as 0.49. Secondly and consistent with first faulting,a NE-SW trending concurrent extensional direvtion produce a local normal faulting presented by a (σ3)28°±18° trend in horizontal plane. Furthermore, between 2003 and 2010 years, bigger than M=3.3, 12earthquakes on Ganos Fault and its vicinity, determined the focal mechanisms and inversion analysisresults indicate that a strike-slip faulting is active along the fault. In the inversion of the earthquakes, astrike-slip faulting presented a (σ1) N 276°±7° and (σ3) N 6°±6° trends and Rm ration calculated as 0.44.This result is consistent with the results of fault kinematic analysis and offer as a transtensional characteralong the fault. According to rose diagram that was generated by remote sensing lineament analysis.Determined 223 lianements have mainly parallel to the Ganos Fault. The stress states from remote sensingstudies are consistent both fault kinematic analysis and inversion of the earthquakes faocal mechanismresults. Ganos Fault is an active strike-slip fault by the transtensional character since Late Pliocene.