Early Pliocene molluscs from the easternmost Mediterranean region (SE Turkey): biostratigraphic, ecostratigraphic, and palaeobiogeographic implications

Abstract

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.

Fresh- and Brackish-Water Cold-Tolerant Species of Southern Europe: Migrants from the Paratethys That Colonized the Arctic

“…Ecrobia sp. inhabited the northeastern Mediterranean in the Latest Miocene [117]. The extinct species E. polysarca (Cossmann and Peyrot, 1919) has been described from the Neogene deposits of Aquitaine, at the Atlantic coast of France.…”

“…As noted above, they are found in the Middle and Upper Miocene deposits of the southern coast of the Caspian Sea, in Iran [116], where the northeastern part of the Araks Strait was situated. Moreover, by the end of the Miocene, they appeared in the northeastern Mediterranean [117], i.e., in the southwestern part of the Araks Strait.…”

Traces of Mediterranean origin Holocene transgression in the drainage basin of Riva-Çayağzı Creek of the Black Sea (northeastern İstanbul-Turkey)

“…According to the Late Quaternary stratigraphy of the Black Sea, during the last glacial melting period (about 13,000-160,000 years ago), fresh waters flooded into the Caspian Sea, Black Sea, and Sea of Marmara with the melting of some main rivers such as the Bug, Danube, Dniester, and Dnieper due to the melting of Scandinavian glaciers, and the complete region became a partly interconnected freshwater lake system before the Mediterranean transgression. The first Mollusca community is the representative community of this period and the stratigraphic correspondent of this period is called Neoeuxinian (Late Pleistocene) (Görür et al, 2001;Yanko-Hombach, 2007;Yanko-Hombach et al, 2007;Büyükmeriç, 2016;Tawfık et al, 2017;Büyükmeriç et al, 2018). Some rivers flowing into the Black Sea deposited sedimentary lithological materials in the areas where rivers meet the seas.…”