Neogene Stratigraphy and Structural Elements of the Aksu Basin (Antalya, Turkey)

The Tauride fold and thrust belt formed during similar to N-S convergence between African and Eurasian plates since Cretaceous time. This movement led to the development of a complex morpho-tectonic structure, so-called 'Isparta Angle' during the early stage of the Neogene time. In Miocene time, the western and central Taurides and the inner part of the Isparta Angle became overlain by marine sedimentary basins which are characterized by clastics and carbonates. Aksu Basin which is determined as study area is one of these marine basins and is located in the center of the Isparta Angle. Therefore, Aksu Basin contains the geological records of the crustal deformation occurred during the Neogene period. The sedimentary infill of the Aksu Basin is mainly characterized by marine clastics with more than 1 km thick from the Middle Miocene to Pliocene. The pre-Pliocene basin infill was subjected to intense deformation. Sedimentary sequence of the Aksu Basin starts with Burdigalian-Langhian Oymapinar Limestone which unconformably overlies the basement unit. The lithostratigraphy in the north is different from that of the south of the basin. The youngest Miocene unit in the north of the basin is the Tortonian aged and the units deposited between Tortonian and Pleistocene is missing in the sequence. On the other hand, the sequence is more complete in the south of the basin. In addition to lithostratigraphic features, the structural elements which are forming the Aksu Basin are also carried out during this study. These are the Aksu and Kapikaya thrusts. Field observations and results obtained from the kinematic measurements along the key structural zones show that Aksu Basin developed through four different tectonic phases. While the first phase is similar to E-W extensional phase which is related to opening of the basin, the second phase is similar to N-S compressional Lycian phase. The third phase is similar to E-W compressional (Aksu) phase, which is the most prominent phase in the basin. N-S extensional phase is determined as the fourth and the last tectonic phase. Under the light of whole data, presence of the E-W shortening which is active between Serravalian and Early Pliocene in the center of the Isparta Angle is interesting given the plate tectonic setting driven by N-S convergence of the Africa and Eurasia. The seismic tomography images of the mantle below the Isparta Angle indicates that there are two separate slab segments (Cyprus and Antalya slabs). Therefore, an important impact of the Antalya slab should be expected in the Mio-Pliocene and even modern evolution of the Isparta Angle and the uplift of the Taurides.