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The basement units of the study area are Paleozoic-Mesozoic Keban metamorphics and Late Cretaceous Elazığ magmatics. As a result of tectonic events caused by final collision in Middle Maastrichtian, all these basement units were juxtaposed, uplifted, eroded and acted as a source area for the Maastrichtian-Paleogene basins. Upper Cretaceous-Paleogene deposits were systematically sampled in order to determine their ages and lithologies. Due to new age findings and stratigraphical positions the marine units were identified as; Harami, Seske and Kırkgeçit formations. Late Oligocene-Early Miocene Alibonca formation and Pliocene Karabakır formation are the other units of the study area. Maastrichtian-Thanetian Harami formation is formed by grainstone intercalated with sandstone at the bottom and white limestone at the top. Early Lutetian Seske formation consists of conglomerate at the bottom and much nummulitic, carbonate cemented sandstone with ophiolitic fragments at the top. Kırkgeçit formation consists of sandstone-siltstone-limestone intercalation, and it is early Bartonian-early Chattian. Late Chattian-middle Burdigalian Alibonca formation consists of conglomerate at the bottom, reefal limestone in the middle and clayey limestone intercalated with algal limestone at the top. Pliocene Karabakır formation is formed by conglomerate-mudstone and locally by intercalations of pyroclastics and lavas. Pertek Andesite and Basalt Members are both vertically and laterally transitional with sedimentary lithologies of the Karabakır formation. There is no data to date the lithology; however, it was assumed that it had been Pliocene in age according to the lithostratigraphical succession. In the study area, macrotectonic events were experienced in Late Cretaceous, Early Eocene, middle-late Lutetian, Middle?-Late Miocene and in the Latest Pliocene. During the last tectonic phase, the Anatolian plate bounded by the East Anatolian Fault (EAF) in E-SE began to move westward, and the right lateral strike slip Pertek Fault activated in the study area.

The mollusc faunas from Pliocene deposits of the Hatay-İskenderun region were investigated at nine localities and complemented with three localities from earlier studies. The Pliocene units were deposited in three adjacent subbasins, Hatay-Samandağ (HS), Altınözü-Babatorun (AB), and İskenderun-Arsuz (İA); the first two are also known as the Hatay Graben. Basin configurations and shape, environmental evolution, and faunal compositions were affected by differential tectonic histories since the Late Miocene. In total 162 species (94 gastropod, 61 bivalve, and 7 scaphopod) are recorded, 80 of which are recorded for the first time from the region. The occurrence of tropical stenohaline benthic taxa (such as Persististrombus coronatus and some conid gastropod species) and a number of chronostratigraphically well-constrained mollusc species shows a Zanclean age. The base of the Early Pliocene is also shown by the occurrence of planktic foraminifer assemblages corresponding to MPL1 and MPL2 biozones and the nannoplankton Amaurolithus delicatus assemblage. The Early Pliocene Hatay molluscan assemblages allow for palaeobiogeographic comparisons across the Mediterranean. The Pliocene marine fossiliferous deposits are assigned to the Mediterranean Pliocene Molluscan Unit 1 (MPMU1) of the western Mediterranean and Atlantic regions. However, the eastern Mediterranean assemblages are notably poorer in species and in particular a number of thermophilic groups are lacking. This marine biodiversity gradient has been a characteristic feature of the Mediterranean ever since the Pliocene.

The Ereğli‐Ulukışla Basin which is the focus of this study is situated at the south‐eastern edge of the Central Anatolian Cenozoic basins (Tuzgölü, Haymana, Çankırı‐Çorum, and Sivas), and is divided into two sub‐basins, the Aktoprak (AT) and Hacıbekirli‐Tepeköy (HT). These sub‐basins mainly comprise a stratigraphically discontinuous and laterally variable series, represented by ‘fluvio‐lacustrine’ siliciclastic and carbonate sediments deposited over a wide range of environments, including meandering and braided rivers, coastal fluvial and fan deltas, mixed carbonate‐siliciclastic shores, dry lake flats, and coal‐bearing swamps. In the Ereğli‐Ulukışla Basin, higher palaeotopographic conditions existed in the AT because of the uplift of the Central Anatolian Plateau during late Middle Miocene (Serravallian)‐early Late Miocene (Tortonian) and the subsequent uplift of the Taurus Mountains in the latest Miocene (Messinian) as deduced in the Tepeköy region (northeast) of the HT sub‐basin. Diversity and abundance of archaic pollen (Normapolles) in the pollen biostratigraphy decreased from the Eocene to Oligocene, while forms with advanced angiosperm morphology (post‐Normapolles), were observed with the increase in post‐Normapolles during the Miocene. The dominance of woody angiosperms in the pollen assemblages, and increasing variety and abundance of ‘open herbs’ and shrub pollen from the Early Miocene to Late Miocene defines an important change in flora. Furthermore, the palaeoclimatic conditions changed from humid‐subtropical to warm‐temperate during the sediment deposition in the Ereğli‐Ulukışla Basin. Recurrent arid phases during the Late Miocene are indicated by the deposition of reddish caliche conglomerates in broad dry lake flats (HT), and evaporites in local playa lakes (AT), respectively.