Revised late Cenozoic foraminifer biostratigraphy of the Eskiköy Formation (Aksu Basin), SW Turkey and its paleoenvironmental conditions

Abstract

The Aksu Basin, near Antalya, is an important area from many aspects of the geology as it hosts the youngest marine deposits of the western Taurides in southwestern Turkey. These marine deposits play an important role in revealing the response of the Eastern Mediterranean coasts to the post-Zanclean transgression following the Messinian Salinity Crisis and provide a chronological record for detailing the late Cenozoic regional tectonic and sedimentary features. Therefore, biostratigraphic reconstruction of this basin is essential to enhance our understanding of the late Cenozoic evolution of the region and the response of the Eastern Mediterranean realm to climatic shifts. Here, we present an updated foraminifer biostratigraphy of the topmost part of the Eskiköy Formation in the Aksu Basin, a member of the Neogene Antalya basins. The studied Kargı section, located in the northern part of the Aksu Basin, contains planktic foraminifer species such as Neogloboquadrina pachyderma , Globigerinoides tenellus , Globigerinoides obliquus obliquus, and Globoturborotalita rubescens, and benthic foraminifers Bulimina marginata and Saidovina karreriana. These species are important bioevent markers in the Mediterranean Region. Accordingly, we update the stratigraphic range of the Eskiköy Formation found in southwestern Turkey extending it to the Pleistocene falling in MPle1a Neogloboquadrina spp. sx Interval Subzone, more specifically between 1.54 and 1.36 Ma, which previously was considered to be of Pliocene age. This age interval is also in agreement with the previous studies that reported Calabrian-Chibanian aged marine deposits in the Mut Basin, southern Turkey. • Pleistocene bioevent marker planktic and benthic foraminifers were identified. • The sedimentation of the Aksu Basin in southwestern Turkey did not end in the Late Pliocene but continued during the Calabrian. • The Aksu Basin marks a period of low temperatures and lowered sea-level stands during the Calabrian.