Fission-track evidence for late Oligocene and mid-Miocene activity along the North Anatolian Fault in southwestern Thrace

Apatite fission-track (FT) analyses of sandstone samples collected across the trace of the Ganos segment of the North Anatolian Fault (NAF) in south-western Thrace (Turkey) indicate that a significant structural discontinuity was in existence at least by the latest Oligocene. Such discontinuity had a complex kinematic history, as exhumation south of it occurred during the latest Oligocene and north of it during the mid-Miocene. Our data imply that early Pliocene westward propagation of the NAF in the Marmara region followed a pre-existing structural discontinuity; such discontinuity could be related to the development of the Intra-Pontide Suture, marking the terminal closure of the Intra-Pontide Ocean during the Oligocene.