Estimation of the pre-North Anatolian Fault Zone pseudo-paleo-topography: A key to determining the cumulative offset of major post-collisional strike-slip faults

Abstract

Abstract Geometric analysis of the morphological elements in a fault-controlled environment is a widely used application to investigate active tectonics. In this study, we analyze recent topographical data to reconstruct an inherited landform assumed to have been formed and then continuously deformed by multiphase tectonics. Retracing the steps of this complex evolution would allow for the parameters of the faulting kinematics to be deduced. Here we present a detailed description of the methodology by both graphical and analytical approaches and provide quantitative data for constraining fault behavior. This case study focuses on the high topography of northern Anatolia, which is believed to have formed during the Early Miocene by significant uplift subsequent to the major phase of plate collision in this area. This paleo-topography was later cut and dissected after the initiation of a plate-bounding, continental strike-slip fault zone called the North Anatolian Fault Zone (NAFZ). Results of our analysis reveal that the southern part of the studied portion of the NAFZ tilted westward with a maximum uplift of 290 m. Tilting-corrected offsets, measured along the NAFZ, show that the average dextral displacement is 72 km. However, measured offsets increase up to 100 km towards the westernmost portion of the fault zone (western part of the Almacik Block). We discuss the possibility of analyzing large-scale morphotectonic structures to shed light on some debated points related to the NAFZ evolution. The methods described here can be applied to other post-collisional strike-slip faults worldwide and also to smaller scale morphological structures.