first completely submerged, as fossils of nannoplankton and planktonic foraminifera found in marl deposits suggest a shallow, "open-marine" environment. It then became "completely filled" by these marl deposits, then deltaic conglomerate deposits, and finally lacustrine marl deposits. Meanwhile, by the latest Miocene/early Pliocene, continued tectonic activity had caused the Aksu Basin (specifically the present-day northern part, the Aksu-Karpuzçay sub-basin) to become uplifted and tilted towards the south. Deposition was now happening further south, forming the Yenimahalle-Çalkaya sub-basin. Sediment was now coming from the Bey Dağları platform to the west, which had been uplifted in the meantime. Rising sea levels had left the Yenimahalle-Çalkaya sub-basin underwater, leading to what Üner et al describe as a shallow marine shelf environment. Üner et al attribute the alluvial fan-delta of the Eskiköy Formation, and the "shallow marine siltstone-marl alternations" of the Yenimahalle Formation to this period. According to Kaya, the Yenimahalle and Çalkaya Formations were deposited during this period. In the Late Pliocene ( 3.6-2.6 MYA), sea levels dropped and the southern Aksu Basin once again became dry land. On the western side of the basin, the Antalya Fault spawned cold springs, which produced the Antalya tufa and travertine deposits. Quaternary During the Quaternary period, the Aksu River cut a new gorge – not in the same place as the Eskiköy canyon; the river's course had changed in the meantime. Also during this time, the most recent layer of the Aksu Basin was formed: the Belkis Conglomerate, in the middle Pleistocene, by fluvial terraces. Component strata The stratigraphy of the Aksu Basin is well documented, although the specific delineation of formation names, ages, and boundaries are varied. This article follows Kaya's terminology. Aksu Formation According to Ersin Kaya, the Aksu Formation is the oldest layer of the Aksu Basin. It is mixed with the similar-aged Karpuzçay Formation. Based on fossil records, the Aksu Formation has been dated to the Langhian through Tortonian periods (i.e. 16-7 MYA). Its maximum thickness is about 1200 m. The Aksu Formation's type localities are in the northeast and northwest parts of the Aksu Basin. The formation's composition is somewhat varied in different places. The western part of the Aksu Formation consists of "poorly sorted conglomerate and conglomeratic sandstone... composed of rounded clasts of fine-grained, beige micritic Jurassic limestone and Triassic light gray limestone and yellow sandstone". In the east, the formation contains "abundant clasts of red and green radiolarites,