Türkiye Jeoloji Bülteni

Quaternary Development of the Gölpazarı Basin (NW Turkey)

Abstract: The Gölpazarı basin is a pull-apart basin, that located in the northwestern Turkey, is not well-advertisedin literature against its ideal geometric features. The basin floor is located at an altitude of 500 m with asize of 12 km in length and 4.5 km in width in ENE-WSW direction. The basin which has developed relatedto the right-lateral Gölpazarı fault, is bounded by strike-slip faults in the NW and SE edges and by normalfaults in the NE and SW margins. The basin floor has tilted towards west as a result of the relative activitiesof these faults. As represented by the basin fill deposits and geomorphology, the Gölpazarı basin was a closed depression and then by the opening of a strait in the south of the basin by the Akçay stream, the basinwas opened to external drainage in the early Quaternary. The existence of a thick Quaternary sequenceindicates that the capturing of the drainage basin by the external drinage has occured relatively young.Because of the close position of the basin to other pull-apart basins that developed under the control of thenorthern and middle strands of North Anatolian Fault Zone and origination by the right-lateral strike-slipregime have call to mind a genetic origination within the shear zone of the North Anatolian Fault Zone.