Geological and Geophysical Observations on the Tectonic Features of Western Part of the Afyon-Akşehir Graben: a Contribution To the Arguments on the Two-Stage Extension Model

Abstract

The NW-SE trending tectonic contact between the metamorphic basement and the Neogene sedimentary rocks, located at the western side of the Afyon-Akşehir Graben, is interpreted as a reverse fault and is named as the Sultandaǧi{dotless} fault by some researchers. On the contrary, other workers claim that the Sultandaǧi{dotless} fault is a normal fault. Some researchers define the Yakasenek reverse fault which is cut by the Sultandaǧi{dotless} normal fault. In this study, the geological and geophysical studies have been performed on this tectonic contact. The tectonic contact that corresponds to the Yakasenek reverse fault was determined as a NE-dipping plane using with the 'Seismic Beam Steering' method. The identification of the NE-dipping plane instead of SW-dipping shows that the Yakasenek reverse fault, which is interpreted as a product of the Miocene-Pliocene contraction supporting two-stage graben model, does not exist. There is also no field evidence of reverse faulting in the area.