Tectonic investigation of Central Anatolia, Turkey, using geophysical data

Abstract

Central Anatolia in Turkey includes a number of internal basins and quite complex geology, but only three major faults can be observed on the surface. There are limited amount of investigations on the tectonic development, structure and history of this area. In this study, tectonic model of the Central Anatolia was investigated using geophysical data and it was compared with recently suggested tectonic models. Existence of two strike-slip faults that have orientations similar to the North Anatolian and East Anatolian Faults in the triple-junction area around the Bingol–Karliova region (eastern Turkey), led some geoscientists to consider the probability of another tectonic escape model in Central Anatolia. Strike-slip characteristics and slip directions of the Sereflikochisar–Aksaray and Ecemis Faults, and the geographical proximity of them are main reasons to consider this model. In this study, the tectonic escape model was investigated and criticized in detail using regional aeromagnetic, gravity, seismic and seismological data. Tectonic developments, faults and their relevance in tectonic setting of the Tuzgolu Basin, together with the comparison of the tectonic escape, and most recent wrench tectonic issues are comprehensively discussed. According to results of this study, existence of tectonic escape between the Sereflikochisar–Aksaray and Ecemis Faults, and geological reasons behind the model are found contradictory requiring geological and geophysical proofs. Moreover, strike direction of the Sereflikochisar–Aksaray Fault is also controversial. Instead of this, a recent model, the regional wrench tectonics appears more reasonable for Central Anatolia that was also supported by the GPS measurements, previous paleomagnetic studies and some recent papers. Geophysical investigation results pointed out that the counter-clockwise rotational movement of the Kirsehir Block to the east of Tuzgolu Basin has been driven by the Kirikkale–Erbaa and Sereflikochisar–Aksaray Faults and the area around the northernmost corner of the Lake Tuzgolu might be the hinge point for rotation, causing intense earthquake activity localized around the hinge point.