The North Anatolian Fault Zone: distributed Neogene deformation in its northward convex part

Abstract

The North Anatolian Fault Zone is composed of two almost rectilinear branches which join in a northward convex bend. In this bent zone, the Pontide-Anatolide collisional system has been cut across by two transpressional belts of fold-and-thrust and wrench faults of lower Neogene age. These structures were reactived during the Neotectonic period, the time of deposition of the Pontus Group. For both of these deformational events, and up to the present, the tectonic regime remained generally transpressional, with a NW-SE direction of compression and a NE-SW direction of extension. It is only recently, during the Upper Pleistocene, that the dextral wrench faults became more localized and more straight than previously. The complexity of the eastern part of the North Anatolian Fault Zone is better understood if one takes into account the role of inherited Miocene-Pliocene transpressional structures.