No abstract

The sedimentary record of the Caspian Basin is an exceptional archive for the palaeoenvironmental, palaeoclimatic and biodiversity changes of continental Eurasia. During the Pliocene-Pleistocene, the Caspian Basin was mostly isolated but experienced large lake level fluctuations and short episodes of connection with the open ocean as well as the Black Sea Basin. A series of turnover events shaped a faunal record that forms the backbone of the Caspian geological time scale. The precise ages of these events are still highly debated, mostly due to the lack of well-dated sections. Here, we provide an integrated magneto-biostratigraphic age model for two sections from the Kura Basin e Goychay and Hajigabul. Our results reveal several major intervals with elevated salinity, associated with mesohaline faunas, and propose the following age constraints: 1) The Productive Series-Akchagylian boundary is marked by a marine transgression from the open ocean that occurred around the Gauss-Matuyama reversal (~2.7e2.6 Ma); 2) The Akchagylian-Apsheronian transition is characterized by a regression event and introduction of a new, "Pontocaspian" mollusc assemblage, dated within the Reunion subchron (~2.13 Ma). The ostracod assemblages of the two sections do not show a major faunal turnover here; 3) The early Bakunian transgression occurs after the upper Apsheronian lowstand (0.85e0.83 Ma). We conclude that major transitions in the age-indicative mollusc groups sometimes occur at different time intervals (i.e. diachronic) and are highly depended on the local depositional environments. A highresolution interdisciplinary approach on sections outside the Kura Basin is required to better understand the potential diachroneity of these turnover events in the entire Caspian Basin.

The early Pleistocene travertines from Kocabaş in the Denizli Basin (SW Turkey), from which the only known Homo erectus from Anatolia derives, are covered by a succession of lake deposits. So far, the taphonomic history of the site has precluded a detailed palaeoecological analysis. This paper details the sedimentary succession and palaeoenvironmental conditions by analysing the micro-and macropalaeontological species compositions. These data provide direct evidence of the opportunities and limiting factors of the environment inhabited by hominins during the early Pleistocene. Four distinctive lithostratigraphic units are recognized in the Quaternary succession, consisting of: Lower Travertine, Lower Conglomerates, Upper Travertine, and Upper Conglomerates. These units correspond to an alternation of lacustrine limestone, fluvial-lacustrine siliciclastic deposits and subaerially precipitated travertine accumulations. The age of the succession is constrained by cosmogenic nuclide concentration, palaeomagnetic measurements and large mammal biostratigraphy which suggest deposition occurred between ~1.6 and 1.2 Ma. The travertine succession contains a moderately diverse macromammal fauna, including Homo erectus, decapod crustaceans and leaf imprints. The herbivore association likely dwelled in a mixed landscape during temperate and humid climatic conditions, supported by negative δ 18 O values from analysed gastropod and bivalve shells. The presence of an anomalohaline lake is indicated by an abundant and well-preserved ostracod community, consisting of alkaline tolerant taxa and freshwater genera further supported by the presence of cardiid bivalves.

The upper Miocenelower Pliocene sedimentary succession of the Denizli Basin (SW Anatolia) displays a unique record of undisturbed stratigraphy and provides an excellent opportunity to study long-term palaeoecological changes. This paper documents the ostracod assemblages of two sections of the Neogene Kolankaya Formation, resulting in the following taxonomic, palaeobiogeographic and ecological interpretations. The ostracod assemblages from the two sections consist of a mixture of oligohaline to mesohaline tolerant taxa but expose fundamental differences in their composition. This is reflected by the fact that out of 32 determined species, both sections only have 3 in common. In the stratigraphic older succession, the diverse ostracod fauna resembles taxa known from the Paratethys. Faunal relations to the brackish lake habitats of the Euxinic and Pannonian basins are apparent and the palaeobiogeographic significance of the fauna is discussed. The ostracod association of the younger section indicates a low brackish water habitat with fluctuating salinities, most likely in the oligohaline range. The ostracod assemblage of the Kolankaya Formation only permits a broad age assignment to the late Mioceneearly Pliocene.