Quaternary time scales for the Pontocaspian domain: interbasinal connectivity and faunal evolution

The Pontocaspian (Black Sea - Caspian Sea) region has a very dynamic history of basin development and biotic evolution. The region is the remnant of a once vast Paratethys Sea. It contains some of the best Eurasian geological records of tectonic, climatic and paleoenvironmental change. The Pliocene-Quaternary co-evolution of the Black Sea-Caspian Sea is dominated by major changes in water (lake and sea) levels resulting in a pulsating system of connected and isolated basins. Understanding the history of the region, including the drivers of lake level and faunal evolution, is hampered by indistinct stratigraphic nomenclature and contradicting time constraints for regional sedimentary successions. In this paper we review and update the late Pliocene to Quaternary stratigraphic framework of the Pontocaspian domain, focusing on the Black Sea Basin, Caspian Basin, Marmara Sea and the terrestrial environments surrounding these large, mostly endorheic lake-sea systems

Reconciling the stratigraphy and depositional history of the Lycian orogen-top basins, SW Anatolia

Terrestrial fossil records from the SWAnatolian basins are crucial both for regional correlations and palaeoenvironmental reconstructions. By reassessing biostratigraphic constraints and incorporating new fossil data, we calibrated and reconstructed the late Neogene andQuaternary palaeoenvironments within a regional palaeogeographical framework. The culmination of the Taurides inSWAnatolia was followed by a regional crustal extension from the late Tortonian onwards that created a broad array of NE-trending orogen-top basins with synchronic associations of alluvial fan, fluvial and lacustrine deposits. The terrestrial basins are superimposed on the upper Burdigalian marine units with a c. 7 myr of hiatus that corresponds to a shift from regional shortening to extension. The initial infill of these basins is documented by a transition from marginal alluvial fans and axial fluvial systems into central shallow-perennial lakes coinciding with a climatic shift from warm/humid to arid conditions. The basal alluvial fan deposits abound in fossil macro-mammals of an early Turolian (MN11–12; late Tortonian) age. The Pliocene epoch in the region was punctuated by subhumid/humid conditions resulting in a rise of local base levels and expansion of lakes as evidenced by marsh-swamp deposits containing diverse fossilmammal assemblages indicating late Ruscinian (lateMN15; late Zanclean) ageWe are grateful for the support of the international bilateral project between The Scientific and Technological Research Council of Turkey (TUBITAK) and The Russian Scientific Foundation (RFBR) with grant a number of 111Y192. M.C.A. is grateful to the Turkish Academy of Sciences (TUBA) for a GEBIP (Young Scientist Award) grant. T.K. and S.M. are grateful to the Ege University Scientific Research Center for the TTM/002/2016 and TTM/001/2016 projects. M.C.A., H.A., S.M. and M.B. have obtained Martin and Temmick Fellowships at Naturalis Biodiversity Center (Leiden). F.A.D. is supported by a Mehmet Akif Ersoy University Scientific Research Grant. T.A.N. is supported by an Alexander-von-Humboldt Scholarship. L.H.O. received support from TUBITAK under the 2221 program for visiting scientists

Postglacial floodings of the Marmara Sea: molluscs and sediments tell the story

The early Holocene marine flooding of the Black Sea has been the subject of intense scientific debate since the “Noah’s Flood” hypothesis was proposed in the late 1990s. The chronology of the flooding is not straightforward because the connection between the Black Sea and the Mediterranean Sea involves the intermediate Marmara Sea Basin via two sills (Dardanelles and Bosphorus). This study explores the chronology of late Pleistocene–Holocene flooding by examining sedimentary facies and molluscs from 24 gravity cores spanning shelf to slope settings in the southern Marmara Sea Basin. A late Pleistocene Ponto-Caspian (Neoeuxinian) mollusc association is found in 12 of the cores, comprising 14 mollusc species and dominated by brackish (oligohaline–lower mesohaline) endemic taxa (dreissenids, hydrobiids). The Neoeuxinian association is replaced by a Turritella–Corbula association at the onset of the Holocene. The latter is dominated by marine species, several of which are known to thrive under dysoxic conditions in muddy bottoms. This association is common in early Holocene intervals as well as sapropel intervals in younger Holocene strata. It is an indicator of low-salinity outflows from the Black Sea into the Marmara Sea that drive stratification. A marine Mediterranean association (87 species) represents both soft bottom and hard substrate faunas that lived in well-ventilated conditions and upper mesohaline–polyhaline salinities (ca. 25 psu). Shallower areas were occupied by hard substrate taxa and phytopdetritic communities, whereas deeper areas had soft bottom faunas. The middle shelf part of the northern Gemlik Gulf has intervals with irregular and discontinuous sedimentary structures admixed with worn Neoeuxinian and euryhaline Mediterranean faunas. These intervals represent reworking events (slumping) likely related to seismic activity rooted in the North Anatolian Fault system. The core data and faunas indicate an oscillating postglacial sea-level rise and phases of increased/decreased ventilation in the Marmara Sea during the Holocene, as well as palaeobiogeographic reorganisations of Ponto-Caspian and Mediterranean water bodies since the latest Pleistocene (<30 ka). The findings contribute to arguments against a single catastrophic flooding of the Black Sea at about 7.5 ka (Noah’s Flood). © 2016, Springer-Verlag Berlin Heidelberg

Molluscan biostratigraphy of early miocene deposits of the kale-tavas and Acipayam Basins (Denizli, Sw Turkey)

In the present work, a stratigraphic framework of the early Miocene units of the Kale-Tavas and Acipayam deposits is proposed. Two stratigraphic sections from the brackish-marine deposits of Aquitanian (Yenidere formation) and three sections from the shallow marine units of late Burdi-galian (Kale formation) age have been logged. In total 23 mollusc species are identified similar to those of the areas in the Mediterranean province. The fauna indicates that the Mediterranean Tethys occupied the southwestern part of the Denizli region only during the early Mocene. A tectonic pulse in the basin during the early Miocene may have been very important to understand the limits of marine Tethyan influence in the area

New cockles (Bivalvia: Cardiidae: Lymnocardiinae) from Late Pleistocene Lake Karapınar (Turkey): Discovery of a Pontocaspian refuge?

Three species of lymnocardiine cockles (Bivalvia: Cardiidae) from Late Pleistocene deposits near Karapınar (Konya Basin, Anatolia, South Turkey) are reported. Two of the three species are described as new (Monodacna pseudocolorata and Adacna yaninae). A third species (Hypanis ?plicatum) is represented by two incomplete valves. Radiocarbon ages of circa 35–43 kA were obtained for the fauna. The lack of lymnocardiine cockles in Pleistocene Anatolian inland lake deposits raises the possibility that the new record represents a short lived occurrence. We raise the possibility that the Karapınar Basin cockles may have been introduced from the Black Sea region through avian dispersal, although we cannot rule out their cryptic existence in the region during the Pleistocene. The apparent absence of Monodacna colorata group of cockles in the Black Sea Basin during the last glacial raises the possibility that the Karapınar region may have served as a true refugium rather than just a sink for Pontocaspian biota. © 2016 Elsevier Ltd and INQU

Middle-late Pleistocene marine molluscs from Izmit Bay area (eastern Marmara Sea, Turkey) and the nature of Marmara - Black Sea corridors

In this study, marine Pleistocene mollusc faunas from deposits along the southern shores of the Izmit Bay area (Marmara Sea, Turkey) are reviewed. Ten samples from five localities spanning middle and late Pleistocene intervals are assessed and compared to four samples of a Holocene age. For the Pleistocene fauna, a total of 59 mollusc species (33 bivalve and 26 gastropod species) are recorded, some of which are reported for the first time for this region. The middle Pleistocene fauna bears large resemblance to the late Pleistocene faunas, even though marine conditions were lacking during sea-level drops in the Marmara Sea Basin in intervening times. The middle Pleistocene mollusc fauna is dominated by species that typify the so-called Uzunlarian faunas while the late Pleistocene mollusc fauna is indistinguishable from Karangatian faunas of the Black Sea Basin.Several common species (including Bittium reticulatum, Rissoa spp. and Lucinella divaricata) show that the both Uzunlarian and Karangatian assemblages of Yalova fauna mainly represent seagrass palaeoenvironments. Palaeosalinities estimates for the Yalova area are uppermost mesohaline to polyhaline, typically around or above 20 psu, which is almost similar to the optimum salinity estimates for the middle Pleistocene Uzunlarian. However, it is slightly lower then the Upper Pleistocene Karangatian, representing the location of the Yalova area in an embayment with freshwater input at that time.The Yalova sections are located in the southern flank of the North Anatolian fault system responsible for a strong local uplift of the study area. The sections contain evidence for three marine high stands, separated by terrestrial intervals. When regional uplift rates (approximately 0.2 mm/y) and oceanic sea-levels are considered it is likely that the three highstand intervals correspond to relative sea level high stands of MIS7, MIS5e and possibly MIS5d but further study is required to confirm such a suggestion. © 2015 Elsevier Ltd and INQUA

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

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. © TÜBİTAK

Pre-and post-deposition stages of messinian evaporites based on facies interpretations in the Hatay Graben and its sub-basins, southeastern Turkey

The Hatay Graben (HG), divided into two sub-basins, Hatay-Samandağ (HS) and Altınözü-Babatorun (AB) consists of very typical deposits of the pre-and post-evaporite stages spaning to the latest Tortonian/early Messinian to Zanclean time. In the graben center (HG/HS), pre-evaporite stage starts with an environmental shallowing episode following deeper sea turbidites (FN1) deposited during early-middle Tortonian time. The basinal shallowing episode trigerred by the late Tortonian tectonics, had involved a siliciclastic-dominated accumulation of coastal sands, small-size fan/Gilbert-type deltas, braided rivers, and f uvial incices and Melanopsis-bearing mudstone (L1), and these kinds of deposition collectivelly reflec a deposition under the estuarine-brackish (oligohaline) conditions (FN2–4). However, in some places (e.g., Hancağız), some pteripod-bearing sandy mudstones and grey mudstones are present within the shallow marine-estuarine/brackish (oligohaline) associations, indicating that relatively deeper environmental conditions, that were temporaly developed within the pre-evaporite succession. The pre-evaporitic environmental f uctutations from brackish to marine was ended by an evaporite-precipitated stage (Vakıf ı Formation), where the gypsum dominated evaporites (FV1) were deposited in the marginal basins as upper gypsum. They are fault-controlled iso-lated/mini basins represented by bedded-selenitic gypsum, mudstone-alternating laminated gysum and locally slumped gypsum. The evaporitic stage was terminated by gyrogonites-bearing mudstone (FV2), which is marked by L2 assigned to the establisment of the second stage estuarine/brackish (oligohaline) environment. In Kuşalanı district, some sandy mudstones that are time equivalent of the FV2, composed of a few Paratethyan mollusk species such as melanopsids, dreissenids and lymno-cardiids that can be tentatively considered as Lago-Mare type deposits formed after the Messinian evaporite stage. Subsequently, Zanclean marine ref ooding was distinguished by different kinds of sediments (e.g., Samandağ Fm), but it is generally onset of the coarse-grained delta, fan/Gilbert-types and followed upward by the wave-tidal-storm-dominated shallow water silisiciclastics (FS1–8), suggesting the graben/basin margin was subjected to a catastrophic or fast marine ref ooding after the MES. In the Graben center, there has not been any clear boundary between the Messinian/Zanclean succesions. In Hancağız section, gypsum blocks (FN 5) beneath Zanclean deposits may be evidence of Messinian Erosion Surface (MES); however, there is no notable time gap between the Miocene and Pliocene units that can be attributed to conformity or low-grade disconformity. This sitution is contrasting to the graben-margin setting, represented by erosional unconformity, where Zanclean deposits sit directly on the Tortonian turbidite unit, lacking upper Tortonian shallow water siliciclastics and Messinian evaporite. This resulted in a late Tortonian tectonics phase (sensu lato: Tortonian erosion surface “TES”). At the same time this evolved a new basin, Altınözü-Babatorun (AB) which is differentiated from the neighboring subbasins by means of its own depositional character represented by alternations of Zanclean shallow water sandstones and pelagic limestone beds or pelagic sills and dykes within the sandy matrix. © 2019 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, German

A Rupelian mangrove swamp mollusc fauna from the thrace basin in Turkey

A Rupelian mollusc fauna from a lignitic coquina overlying the main seam in the Pullukçu lignite mine in the Turkish part of the Thrace Basin is described. The low diversity assemblage comprises twelve gastropods and four bivalve species and is dominated in specimen numbers by Cyrenidae, Dreissenidae, Rissoidae, Thiaridae, Potamididae and Melanopsidae. Ecologically, the taxa indicate mesohaline to polyhaline water conditions and suggest a position far within the mangrove swamp at some distance from the shoreline. In terms of biogeography, the fauna represents a typical Rupelian coastal swamp assemblage, which was rather homogenous at the genus level along all European coasts. Nevertheless, two new thiarid and rissoid genera, represented by numerous specimens, document some biogeographic differentiation from the well-known Rupelian faunas of the North Sea and Eastern Atlantic. For the first time, the enigmatic planorbiform genus Anomalorbina Paul 1996 is also recorded from the Thrace Basin. For the Oligocene, it has been known so far only from the North Sea Basin, emphasizing the current state of poor knowledge of micromolluscs in the Paratethys and Western Tethys. This lack of information on small-sized taxa renders difficult a comparison with other Oligocene faunas of the Paratethys and Western Tethys and documents the limits of paleobiogeographic analyses. Sengoeria and Koskinakra are described as new genera and Vitta rumeliana, Sengoeria thracica, Koskinakra thracica and Sphenia praepusilla are introduced as new species. © E. Schweizerbart’sche Verlagsbuchhandlung (Nägele u. Obermiller)

Fauna and flora of drilling and core data from the İznik Lake: The Marmara and the Black Sea connection

The study deals with on the Quaternary connection of the Iznik Lake between the Gemlik Gulf and the Black Sea located in the Marmara Region. The core and drilling data were evaluated. They were collected at two locations and depths from drilling cores and at the three deepest locations of the lake. A total of 510 samples were examined from the lake-bottom cores. Ostracod, mollusc, nannoplankton, ascidian spicule, and diatom assemblages observed at different levels of the drillings were studied. No foraminiferal data were recorded. Molluscan association such as Dreissena bugensis, D. caspia, Monodacna pontica, Clathrocaspia makarovi, Euxinipyrgula milachevitchi, Euxinipyrgula lincta indicate Neoeuxinian age. Amnicythere olivia, A. stepanaitysae, A. striatocostata, Tyrrhenocythere amnicola and Loxoconcha immodulata of the ostracod assemblage, exhibiting Ponto-Caspian origin, were found. In addition, fossil ascidian spicules comprising various species of Bonetia, Micrascidites, Monniotia, and Rigaudia genera were encountered, probably representing Late Pleistocene to Holocene ages. Campylodiscus echeneis, Cocconeis placentula var. lineata Epithemia turgida var. granulata, Epithemia adnata, Nitzschia commutate and N. vermicularis, from the diatom assemblage are genera and species also found in the İznik Lake and in the Black Sea. Mollusc and ostracod fauna, the Ponto-Caspian origin indicates that the İznik Lake was connected with the Black Sea and the Marmara Sea in the recent period. Thus, the Ponto-Caspian assemblages indicate the early Neoeuxinian (Surozhian) brackish water inundated the study area. Geochronological ages determined by the 14C method from the deposits occurring at 53–54 m above present sea level in the İznik Lake indicate the periods of connection via Iznik Lake during 33,630 to 32,920 cal BP (SK-1) and BP 27,335 to 27,070 cal BP (SK-2). When the position of the deposits is compared with the previously available Late Pleistocene 14C data obtained from the molluscs identified in the nearby Gemlik Gulf at -76 m present water depth and also with the early Khazarian (Middle Pleistocene) age data on the molusc fauna at 130–150 m heights of uppermost terraces above present sea level to NW of the lake, we suggest the influence of a neo-tectonic regime for the occurrence of comparable age deposits at different levels in the region. It may be proposed that a vertical displacement in the order of a 100 m occurred since the late Pleistocene in the İznik Lake area and the lake acquired its present features as a result of the tectonic movements. © 2017 Elsevier Ltd and INQU