Tectono-sedimentary evolution of the Eocene transgressive deposits in the SW Turkey: an overview

Western Anatolia is characterized by N-S and NE-SW oriented extensional neotectonic regime and with E-W, NE and NW-trending depression fields. The Aegean region has been subjected to active N-S extensional tectonics, under the control of the westward movement of the Anatolia plate bounded by the North Anatolian and East Anatolian faults. Tectonic evolution stages of SW Turkey can be divided into four main periods (from latest Cretaceous to the late Miocene). These are in ascending order; (1) Closure of the Pamphylian basin and emplacement of Antalya nappes (during the latest Cretaceous and the Paleocene), (2) Emplacement of Lycian nappes (end of Eocene-Early Oligocene), (3) Forming of the Oligocene molasse basins, (4) Opening of the Baklan and Acıgöl grabens (late Miocene) under the NW-SE and N-S extensional regimes of which has developed simultaneously. The Middle-Upper Eocene sedimentary sequence in Acıgöl (Başçeşme formation), Burdur (Varsakyayla formation) and Isparta (Kayıköy formation) basins (SW Turkey) have commenced with conglomerates and coarse grained sandstones and change to the shale dominated turbidites and limestone interbeds in the upper most part. Generally, the amount of fauna fossils and calcium carbonate content increase upward from the conglomerate to the limestone. The main sedimentary structures of the coarse conglomerate and sandstone constituents in the lower most part of the Eocene sequence indicate the terrestrial (alluvial fan) and transitional (tidal flat) environments. Further more thin bedded sandstone-mudstone alternations point out marine facies (flysch facies) through the eastern part of study area (Isparta region). As a result of this study, it can be mention that palaeoenvironmental changes associated with sea level fluctuation depend on the transgression and tectonic activity.