Archived project

The evolution of Paratethys: the lost sea of Central Eurasia

Goal: Paratethys was a large epicontinental sea, stretching from Germany to China at the beginning of the Oligocene (~34 Myr ago), that progressively retreated by a complex combination of basin infill, glacio-eustatic sea-level lowering and tectonic uplift to its present-day remnants: Black Sea, Caspian Sea and Aral Lake. The influence of Paratethys on global change is still a great unknown, mainly through lack of relevant studies in this terra incognita, although model studies suggest a major effect of sea retreat on climate and environment. The team in this project aims to comprehend the causes of the extreme environmental changes that occurred in Central Eurasia.
High-resolution geochronology together with integrated stratigraphy and geochemical proxies (deuterium, strontium, neodymium) are critical to unravel internal (geodynamics, tectonic uplift) from external (climate, glacio-eustatic sea-level change) forcing factors and to resolve the effects of Paratethys restriction (regional climate perturbations, biotic crises, aridification).

Three time slices exist when progressive sea retreat and variations in interbasinal connectivity generated extreme environmental changes:
1) The birth of Paratethys (~34 Ma), resulting in deposition of anoxic shales during a complex combination of tectonic uplift and global cooling.
2) Its midlife crisis in the middle Miocene (~14-11 Ma) when gateway restriction created massive salt deposits during the middle Miocene climate transition.
3) The demise of Paratethys (~9-4 Ma), transforming open marine environments into lacustrine deltaic systems, and leading to alternating phases of desiccation and flooding.

Updating the chronostratigraphic framework means that we need to critically revise existing (bio)stratigraphic data according to the newest standards, and, above all, we need to look and communicate beyond borders to correlate critical Paratethys events.

The new stratigraphic insights can be used for numerical modeling studies. Moreover, fundamental rock magnetic studies are needed to standardize microfossil iron sulphide (greigite) techniques, intended to revolutionize magnetostratigraphic dating in brackish-lacustrine paleoenvironments.

This multi-disciplinary approach provides the only way to attain a comprehensive system view on long-term Paratethys evolution.

Methods: Geochemistry, Argon-Argon Dating, Modeling, Biostratigraphy, Magnetostratigraphy

Date: 1 January 2011 - 1 January 2020

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Dan V Palcu
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The MagellanPlus workshop "BlackGate" addressed fundamental questions concerning the dynamic evolution of the Mediterranean-Black Sea (MBS) gateway and its palaeoenvironmental consequences. This gateway drives the Miocene-Quaternary circulation patterns in the Black Sea and governs its present status as the world's largest example of marine anoxia. The exchange history of the MBS gateway is poorly constrained because continuous Pliocene-Quaternary deposits are not exposed on land adjacent to the Black Sea or northern Aegean. Gateway exchange is controlled by climatic (glacio-eustatic-driven sea-level fluctuations) and tectonic processes in the catchment as well as tectonic propagation of the North Anatolian Fault Zone (NAFZ) in the gateway area itself. Changes in connectivity trigger dramatic palaeoenvironmental and biotic turnovers in both the Black Sea and Mediterranean domains. Drilling a Messinian to Holocene transect across the MBS gateway will recover high-amplitude records of continent-scale hydrological changes during glacial-interglacial cycles and allow us to reconstruct marine and freshwater fluxes, biological turnover events, deep biospheric Published by Copernicus Publications on behalf of the IODP and the ICDP. 94 W. Krijgsman et al.: Mediterranean-Black Sea gateway exchange processes, subsurface gradients in primary sedimentary properties, patterns and processes controlling anoxia, chemical perturbations and carbon cycling, growth and propagation of the NAFZ, the timing of land bridges for Africa and/or Asia-Europe mammal migration, and the presence or absence of water exchange during the Messinian salinity crisis. During thorough discussions at the workshop, three key sites were selected for potential drilling using a mission-specific platform (MSP)
Dan V Palcu
added a research item
The largest megalake in the record formed in Eurasia during the late Miocene, when the epicontinental Paratethys Sea became tectonically-trapped and disconnected from the global ocean. The Paratethys megalake was characterized by several episodes of hydrological instability and partial desiccation, but the chronology, magnitude and impacts of these paleoenvironmental crises are poorly known. The Panagia section on the Taman Peninsula of Russia is the only place known to host a continuous sedimentary record of the late Miocene hydrological crises of Paratethys. Paleomagnetic measurements allow the development of a polarity pattern that can be used to date the regression events. The Panagia polarity pattern consists of 17 polarity intervals, 9 of normal polarity and 8 of reversed polarity, plus 4 additional short-term polarity fluctuations, that are inferred to correspond to the 11-7.5 Ma interval. We identified four major regressions that correlate with aridification events, vegetation changes and faunal turnovers in large parts of Europe. Our paleogeographic reconstructions reveal that Paratethys was profoundly transformed during the regression episodes, losing~1/3 of the water volume and~70% of its surface during the most extreme events. The remaining water was stored in a central salt-lake and peripheral desalinated basins while vast regions (up to 1.75 million km2) became emerged land, suitable for the development of forest-steppe landscapes. The dry episodes of the megalake match with climate, food-web and landscape changes throughout Eurasia but the exact triggers and mechanisms remain to be resolved. Powered by TCPDF (www.tcpdf.org)
Nevena Andric Tomasevic
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Lacustrine strata record long-term variations in climatic and tectonic perturbations during orogen evolution. Here we use the sedimentological record of the early to middle Miocene intramontane lacustrine Pranjani Basin (Serbia) to study tectonic and climatic variations during the evolution of the Dinaridic orogen. Our study focuses on a Mg-clay-bearing succession that belongs to the second depositional cycle. A detailed sedimentological, mineralogical and geochemical study shows that the investigated Mg-clays bearing succession consists of an alternation of smectite- (± analcime or sepiolite), dolomite-sepiolite and sepiolite layers. We interpret this high-order cyclicity to have been driven by variable water availability, i.e. by the interplay between runoff, groundwater influx and evaporation. Furthermore, we relate these pulses in water variability to wet and dry intervals under semi-arid to arid climatic conditions. Dry intervals produced a negative water balance promoting the deposition of sepiolite - and dolomite - dominated facies. Wet intervals and a positive water balance inhibited much of the terrestrial input and thus favoured the deposition of smectite - dominated facies. Our new data combined with a review of previous studies reveal longer-term basin-wide lake level and chemistry fluctuations, which we relate to closed and open lake phases. We suggest that these phases can be explained by alternating humid and arid phases superimposed on tectonically induced uplift and subsidence. The arid phases led to lake shrinking and deposition of an evaporite-bearing succession. During the intervening humid phase, the lake expanded. In contrast to the lakes formed in the external part of the Dinarides, the lakes that existed in its internal part contain evaporite-bearing successions, indicating that this arid phase was regionally extensive and possibly orographically controlled.
Ljupko Rundić
added a research item
The subject work covers the Belgrade wider area with a total area of about 2,000 km 2. The authors integrated the principal geological and geo-physical data provided by surface works and multidisciplinary elements from the fifty-two wells with depths between 33 and 2,733 m. Explicit paleontolo-gical findings of specialized analytists with determinations of macro-and mi-crofauna and flora are presented both from Neogene formations and the older basinal floor. In addition to conventional petrological descriptions of rocks, microscopic determinations of intrusive and extrusive magmatites were also cited. From the enclosed basin space, the mineralization of deep aquifers is also correlative positioned. From the geophysical data for wells deeper than 400 m, records of well logging measurements were used, with markers based on which valid stratigraphic delimitations were made. Seismic survey sections were the basis for spatial shaping of Neogene sedimentation and basin floor configuration. For in-depth geological interpretations, published and repository gravimetric and geomagnetic maps of different sizes and years were consulted. The authors focused primarily on factometric indicators without entering into variable and debatable theoretical schematizations, especially orogenically complex of subbasin tectonics, in dissonant relations with the younger disjunctive shaped configuration which is visually shown in the reference cross-sections both vertically and laterally. Апстракт. Предметна референца обухвата простор шире околине Бео-града укупне површине око 2.000 km 2. Аутори су објединили капиталне геолошке и геофизичке податке обезбеђене површинским истражи-вањима и мултидисциплинарним елементима из 52 бушотинe са дубинама између 33 и 2.733 m. Конкретни палеонтолошки налази спе-цијализованих аналитичара са детерминацијом макро и микрофауне и флоре, презентовани су како из неогених формација тако и из басенске подине. Осим конвенционалних петролошких описа стена цитиране су и микроскопске детерминације интрузивних и екструзивних магматита. Из затвореног басенског простора корелативно су позициониране и ми-нерализације дубинских аквифера. Од геофизичких података за бушоти-не дубље од 400 m коришћени су записи каротажних мерења, са маркерима на основу којих су извршена валидна стратиграфска раз
Krisztina Sebe
added a research item
Upper Miocene to Pliocene (Pannonian) sediments of the Pannonian Basin System accumulated in the brackish Lake Pannon and the fluvial feeder systems, between 11.6-2.6 Ma. Their stratigraphic subdivision has been problematic for a long time due to the laterally prograding architecture of the basin fill and the historically independently evolving stratigraphic schemes of the neighbouring countries. We correlated the lithostratigraphic units of the Lake Pannon deposits between Hungary and Croatia in the Drava Basin, using lithological, sedimentological and palaeontological data from boreholes and outcrops, and seismic correlation. The Croatica and Medvedski breg formations in Croatia correspond to the Endrőd Fm. in Hungary, comprising shallow to deep water, open lacustrine, calcareous to argillaceous marls. The Andraševec fm. in Croatia corresponds to the Szolnok and Algyő Fms. in Hungary, consisting of sandstones and siltstones of turbidite systems and of clay marls deposited on the shelf-break slope. The Nova Gradiška fm. in Croatia is an equivalent of the Újfalu Fm. in Hungary, built up of a variety of lithologies, including sand, silt, clay and huminitic clay, deposited in deltaic environments. The Pluska fm. in Croatia corresponds to the Zagyva Fm. in Hungary, consisting of variegated clays, silts, sands and lignites, deposited in alluvial and fluvial environments. Coarse-grained (sand, gravel) basal layers are assigned to the Kálla and Békés Fms. and the Sveti Matej member of the Croatica fm. Coarse-grained intercalations within the deep-water marls belong to the Dorozsma Member of the Endrőd Fm. in Hungary, and to the Bačun member of the Medvedski breg fm. in Croatia. Sediment transport and lateral accretion of the shelf edge in the Drava Basin took place from the N, NW, and W, to the S, SE, and E, respectively. According to the biostratigraphic and chronostratigraphic analyses, the oldest shelf-break slopes in the Mura Basin are more than 8 Ma old, whereas the youngest ones in the southeasternmost part of the Drava Basin may be Pliocene in age (younger than 5.3 Ma). Thus, the 180 km long and at least 700 m deep Drava Basin was transformed into a fluvial plain during the last 3.5 million years of the Miocene.
Dan V Palcu
added a research item
The Northern Aegean region evolved during the Miocene as a restricted land-locked basin with small ephemeral connections to both the Eastern Paratethys (former Black Sea) and Mediterranean. Its biostratigraphic data show mixed Paratethys-Mediterranean components, but the Paratethys fauna has generally been neglected for chronologic reconstructions. Here, we review this biostratigraphic data from a Paratethyan perspective and present revised paleogeographic reconstructions of the Northern Aegean throughout the late Miocene. In the Tortonian, all sub-basins show mainly fluvio-deltaic terrestrial environments with a series of scattered lakes that are predominantly fed by local rivers and short-lived Paratethys connections. The first persisting marine conditions, still alternating with brackish Paratethyan environments, indicate a middle Messinian (late Maeotian) age (6.9–6.1 Ma), when the region formed a semi-isolated (Egemar) sea with multiple marine influxes. The termination of marine conditions is very well documented by a marked palaeoenvironmental change to the brackish water environments that correlate to the Maeotian/Pontian boundary (6.1 Ma) in Eastern Paratethys. During the Messinian Salinity crisis (5.97–5.33 Ma), the Northern Aegean was a brackish water system (Lake Egemar) that formed a passageway for Paratethyan overspill waters towards the Mediterranean. We conclude that the thick evaporites of the Northern Aegean domain do not reflect the classic Mediterranean MSC sequences, but are more likely related to older (Badenian or Maeotian) salinity incursions.
Werner Schwarzhans
added 2 research items
The Lago Mare phase at the end of the Messinian Salinity Crisis (MSC) in the Mediterranean has long been known for the Paratethyan affinities of its biota. The taxonomic level of these affinities and their origin, however, is subject to divergent interpretations. Here, we have studied otoliths of the Gobioidei from late Miocene and early Pliocene deposits from Italy and Greece and revised earlier studies including time-equivalent data from Romania and NW Turkey. Nowadays, gobies constitute the most speciose marine fish family in Europe and the most diverse endemic family in the Ponto-Caspian region. Furthermore, they are highly adapted to nearshore shallow marine, brackish, and freshwater environments, which makes them excellent candidates to explore short-term connections of waterways of different nature. The normal marine late Tortonian and pre-evaporitic Messinian deposits of the studied Italian and Greek locations contained a rich and diverse goby assamblage, but species with Paratethyan affinities were very rare and possibly originated from connections during the early Serravallian (late Badenian) and early Messinian (early Meotian). A rare fauna from a paralic environment from Cessaniti, Calabria, similar to the mangrove environments found in the present-day Guinea coastal area, revealed two species of the family Eleotridae and no gobies with Paratethyan affinities. Cessaniti provides a unique opportunity to recognize the presence of this type of environmental context with a unique gobioid assemblage in the Neogene of Europe. The shallow-water brackish-influenced sediments of Strada degli Archi just below the MSC show an increasing influence of Paratethyan gobiid taxa (Proterorhinus yigitbasi, Zosterisessor exsul n. sp.), which are not present in time-equivalent normal marine environments, but have also been identified in the Dacic Basin of Romania. Sediments of the stage 3 ot the MSC, especially those that accumulated during the Lago Mare event, were dominated by a diverse goby assemblage with Paratethyan affinities, while indigenous Mediterranean goby taxa disappeared probably because of the lack of suitable conditions for neritic demersal stenohaline fishes, except for the nektonic Aphia minuta. The sediments of the stage 3 of the MSC also included in one particular location and level the unusual Enigmacottus socialis n. gen., n. sp., a putative member of the family Psychrolutidae of uncertain origin, which constitutes about 70% of all otoliths obtained from that interval in Italy. Beginning with the Zanclean, the goby assemblage of the Mediterranean shows an almost exclusively Atlantic-Mediterranean composition. A total of 15 new species are described, 12 in the family Gobiidae, two of the Eleotridae, and one putative Psychrolutidae. The new taxa are: Eleotris omuamuaensis n. sp., Eleotris tyrrhenicus n. sp., Lesueurigobius stazzanensis n. sp., Gobius peloponnesus n. sp., Proterorhinus cretensis n. sp., Zosterisessor exsul n. sp., Benthophilus aprutinus n. sp., Benthophilus labronicus n. sp., Caspiosoma lini n. sp., Caspiosoma paulisulcata n. sp., Thorogobius petilus n. sp., Buenia pisiformis n. sp., Hesperichthys gironeae n. sp., Knipowitschia etrusca n. sp., and Enigmacottus socialis n. gen. et n. sp.
The middle Miocene Badenian sediments of the western Central Paratethys are particularly rich in highly diverse associations of gobies, represented by their otoliths. This diversity is caused by significant variations in palaeoenvironmental conditions over short distances. Here we review the rich goby otolith collections from the Carpathian Foredeep in southern Poland and southern Moravia and from the northern Vienna Basin in the Czech Republic and Slovakia. A total of 31 gobiid species are recognised in the Badenian, with six species new to science: Gobius supraspectabilis n. sp., Chromogobius? primigenius n. sp., Odondebuenia agiadiae n. sp., Vanderhorstia prochazkai n. sp., Hesperichthys iugosus n. sp. and Knipowitschia polonica n. sp. The fossil otolith-based genus Hoeseichthys n. gen. is established to account for the deep-water species H. preaclarus (Procházka, 1893) and H. laevis (Weiler, 1942), the latter of which is primarily found in the North Sea Basin. In addition, the rich material now available offers an opportunity to redefine certain species from the area that were described by Procházka between 1893 and 1900. The whereabouts of Procházka's original material is unknown, with the exception of a few undescribed specimens that were recently discovered and are included in this study. Many of the species described by him have proven enigmatic in taxonomic otolith research, and, unfortunately, some of them cannot be redefined even now and will have to remain nomina dubia until his type specimens are rediscovered or declared lost. This study aims at establishing a baseline for the assessment of the evolution of gobies in the Mediterranean and the Paratethys after the separation of these seas, which were still interconnected during the early Badenian. Our study reveals that all major Atlanto-Mediterranean goby lineages, represented by a number of mostly persistent genera, were present in the Badenian. The first taxa of the Ponto-Caspian goby lineages are unambiguously represented only since the late Badenian. The Badenian of the Central Paratethys also contained a few goby lineages which are now not found around Europe but do exist in the Indo-West Pacific (i.e., the Asterropteryx lineage and the Priolepis lineage). There are indications that the identified genera of the Asterropteryx lineage (Amblyeleotris, Vanderhorstia) may have already lived in commensal association with alpheid shrimps at that time. The Paratethyan events during the middle Miocene are reflected in a moderate faunal change in the gobiid composition from the early Badenian to the late Badenian and a major faunal change following the Badenian-Sarmatian Extinction Event.
Dan V Palcu
added a research item
The sedimentary succession along the Belaya River (North Caucasus) provides a record of middle Eocene to Miocene sediments. This time interval is well known for its important climatic transitions (e.g., Middle Eocene Climate Optimum (MECO) and Eocene-Oligocene Transition (EOT)), and changes in basin configuration from Peri-Tethys to Paratethys. The Belaya section contains two intervals marked by oxygen-depleted sediments; the Eocene Kuma Formation of the Peri-Tethys and the Oligocene Maikop Group of the Paratethys. Both are considered important source rocks for hydrocarbon exploration in the Black Sea and Caspian Sea. We present integrated stratigraphic results of the Belaya River section using calcareous nannoplankton biostratigraphy, magnetostratigraphy and 40Ar/39Ar dating. Furthermore, we investigate the geochemical character of the sediments using X-ray fluorescence (XRF) and stable carbon and oxygen isotopes. A middle Eocene age for the lower part of the succession is established from nannoplankton biostratigraphy. The Kuma Formation is dated between 42.1 and 38.4 Ma based on the assumption of constant sediment accumulation rates. A negative oxygen isotope excursion in the middle part of the Kuma Formation could be related to the MECO (~40 Ma). The onset of the Maikop Group is dated around the base of chron C13n at an age of ~33.7 Ma, close to the Eocene-Oligocene boundary. Based on geochemical results, we show that the Kuma Formation and Maikop Group correspond to two different episodes of intensified oceanic oxygen depletion in the succession. We hypothesise that oxygen-depletion as recorded in the Kuma Formation is linked to an increased nutrient input in the open marine Peri-Tethys due to widespread volcanism in the Neotethys subduction zone, while oxygen-depletion as recorded in the Maikop Group is linked to basin restriction caused by the eustatic sea-level fall straddling the Eocene – Oligocene boundary triggering stratified conditions in the semi-isolated Paratethys Sea.
Ljupko Rundić
added a research item
In biostratigraphic research of the Upper Miocene of the Pannonian Basin System, one of the frequently detected and important ostracod genera is Hemicytheria. Among more than 20 species of this genus, Hemicytheria setosa is present in sandy facies of the Lake Pannon sediments in Serbia and Bosnia and Herzegovina. The aims of this study were to describe sexual dimorphism and differences between left and right valve morphology in Hemicytheria setosa. Landmark based geometric morphometrics is applied on the grounds of existence of the homologue pattern of the fossae and pore conuli on the valve surface of this group of ostracods. Significant differences between the sexes and between the left and right valves are detected in the present study. The obtained results indicate that applied methods and chosen landmarks could be useful in the studies of valve ornamentation-variation in fossil and recent Ostracoda.
Annique van der Boon
added a research item
The section of Maikop deposits on the Belaya River upstream of the town of Maikop is characteristic of Western and Central Ciscaucasia; it is well exposed and well-studied and can be considered as the type section of the Maikop Group. The section shows a continuous transition from the underlying white marl of the Belaya Glina Formation to dark clay lying at the base of the Maikop Group. The lower Oligocene part of the section exposes an almost uninterrupted outcrop of the Pshekha Formation and shows unconformities at the base and top of the Polbian Bed. These are overlain by the lower non-carbonate and upper carbonate sub-formations of the Morozkina Balka Formation and the Batalpashinsk and undivided Upper Oligocene Septarian + Zelenchuk formations. This paper contains a detailed lithological description of the section with a summary of its fossils. The composition of the studied microphytoplankton and animal remains, including nannoplankton, planktonic and benthic foraminifers, mollusks, and ichthyofauna is described and paleo-magnetic study results are presented. The study of palynology and dinocysts from the same series of samples was previously completed. The history of the study of the Maikop Group and its subdivision into formations are discussed. This paper discusses the possibility of using the data for correlation and reconstruction of the depositional environment.
Dan V Palcu
added a research item
The mid-Langhian (“Badenian”) flooding fully reconnected the semi-isolated Central Paratethys realm with the Mediterranean and, thereby, drastically changed the middle Miocene paleogeography of Central Europe. Due to the scattered stratigraphic record and scarcity of independent age constraints in some areas, the precise age and underlying mechanism are still debated. We present integrated chronostratigraphic data from five sections in the eastern part of the system to reconstruct the flooding event distal from the strait to the Mediterranean. By applying modern Mediterranean biochronology (planktonic foraminifera and calcareous nannofossils), supplemented by an ⁴⁰Ar/³⁹Ar age on a tuff, we demonstrate that the widespread open marine settings in the NW Transylvanian Basin were definitely installed after 14.9 Ma (MMi4d biozone), and in most areas before 14.4 Ma. In the marginal study area in the SE Carpathian Foredeep, fully marine conditions likely set in slightly later (14.6–14.4 Ma). There, short-lived marine incursions into the brackish environment occurred since the latest Burdigalian (“pre-flooding phase”). The new ages overlap with the flooding in the majority of the Central Paratethys (~ 14.9–14.4 Ma), and with marine overflow into the Black Sea (14.85 Ma). We suggest that the transgression was driven by subsidence of the Pannonian Basin, by creating accommodation space and diminishing barriers between sub-basins, but was likely enhanced by a global sea-level rise. Finally, we speculate that the scarcity of all calcareous material in the SE Carpathian Foredeep before the mid-Langhian flooding might be related to pulses of nutrient-rich brackish and low pH water from the neighboring Black Sea Basin.
Dan V Palcu
added a research item
Various hypotheses exist on the age and origin of the so-called “Pebbly Breccia” unit in the deep-sea record of DSDP Hole 380A of the Euxinian (Black Sea) Basin. Here, we present a detailed study of diatom and nannofossil assemblages of Hole 380A. Our diatom records show a characteristic sequence of appearance of markers species, which we can correlate to the recently established bio-magnetostratigraphic time frame of the Zheleznyi Rog section on the Black Sea coast of the Taman Peninsula (Russia). It shows that the Pebbly Breccia is sandwiched between Upper Maeotian deposits, and must have been deposited at an age between 6.7 and 6.3 Ma. The appearance of nannoplankton and the marine diatom association at above the Pebbly breccia (Unit IVc) suggests a short-term incursion of marine conditions. The age of Unit IVc, based on diatom data, is 6.3-6.1 Ma. The nannoplankton record is mainly represented by species that do not have stratigraphic value. The previously reported presence of Ceratolithus acutus in the Black Sea is explained by misinterpretation of destructed elements of ascidian spicules. We conclude that the Pebbly Breccia is not related to a desiccated Black Sea at Messinian Salinity Crisis times, but it corresponds to a late Maeotian episode of gravitational instability in the SW Black Sea region.
Ljupko Rundić
added a research item
Mt. Avala is located on the southern margin of the Pannonian basin (SPB), a border zone between the uplifted morphostructures of the Dinarides and Carpathian-Balkanides. Similar to the Pannonian basin, tectonostratigraphic evolution of the Mt. Avala area during the last 23 Ma is characterized by syn- and post-rifting processes as well as tectonic inversion. Here, we present the results of field investigations of the Miocene‒Pliocene dynamics that led to different spatial positions of the same stratigraphic units (e.g. Badenian and Pannonian) in a relatively small area. These spatial relationships are interpreted in the context of pronounced block structures (Torlak, Beli Potok and Avala). Torlak Hill represents a horst structure with a core composed of Mesozoic rocks and hillsides composed of the Middle Miocene sediments, which are present at the surface at altitudes up to 336 metres. Nearby, there is the Beli Potok asymmetrical trough that was infilled by the late Miocene sediments. The Torlak horst and the Beli Potok trough structures are separated by the Rakovica normal fault. In some places along the fault line, several geological units are vertically displaced more than a hundred metres. For example, in borehole KGK-14, the Upper Miocene Pannonian marls are observed at a depth of 100 metres below the surface. However, only a few hundred metres away to the northeast, similar Pannonian marls are observed at the surface, at an altitude of about 210 metres. Due to the mentioned vertical movements along the block structures, a composite hilly relief with dominant the Torlak Hill and the Beli Potok Valley was formed.
Werner Schwarzhans
added an update
Dan V Palcu
added a research item
Litho- and biostratigraphic data are provided of 5 stratigraphic sections in Romania covering the “Badenian” marine flooding that occurred in the Central Paratethys during the middle Miocene (Langhian). The dataset includes stratigraphic logs and descriptions of the profiles, and biostratigraphic analyses on calcareous nannofossils and foraminifera. In addition, characteristic stratigraphic features and representative fossils, including tiny Streptochilus foraminifera in the Campiniţa section in the SE Carpathian Foredeep, are presented in photographs. The data show that the flooding is characterized by the sudden abundance of Langhian calcareous nannofossils and foraminifera with a strong Mediterranean affinity.
Darko Spahić
added a research item
The segmented growth of the Markgrafneusiedl normal fault in the late Miocene clastic sediments of the central Vienna Basin (Austria) was investigated by construction of a detailed three-dimensional (3D) structural model. Using high resolution 3D seismic data, the fault surface and marker horizons in the hanging wall and the footwall of the Markgrafneusiedl Fault were mapped and orientation, displacement and morphology of the fault surface were quantified. Individual, fault segments were identified by direct mapping of the deflection of the marker horizons close to the fault surface. Correlating the size of the identified segments with the magnitude of fault drag and displacement distribution showed that fault evolution progressed in several stages. The proposed method allows the detection of segments that are not recorded by the magnitude of displacement or fault morphology. Most importantly, detailed mapping of marker deflections in the hanging wall could help to constrain equivalent structures in the footwall, which may represent potential hydrocarbon traps.
Ljupko Rundić
added a research item
The timing and mode of the marine flooding of the southern margin of the Pannonian basin in SE Europe is still a matter of debate. In central Serbia, integrated bio-magnetostratigraphic data and quantified high-resolution records are completely missing. Here, we provide paleoenvironmental and paleoecological constraints from the Slanci section located near Belgrade that has an excellent preservation of micro-fauna and flora, i.e., planktonic and benthic foraminifera and calcareous nannoplankton. We integrate their quantified records with sedimentological, natural gamma radioactivity and magnetic susceptibility logs and include the non-quantified records of mollusks, corals, and ostracods to reconstruct the regional depositional history. The section shows upper bathyal to outer shelf depositional settings and alternating nutrient bottom conditions. The shallowing upwards trend marked by increasing terrestrial input, attributes it to the early Highstand Systems Tract of the first marine third order sequence in this part of the Pannonian Basin. We infer that the marine flooding in central Serbia took place at an age of ∼ 14 Ma, slightly predating the Langhian/Serravallian boundary (13.82 Ma) and the Badenian Salinity Crisis (∼ 13.8-13.4 Ma) in the Central Paratethys. Our results support an eastwards directed, tectonically forced, flooding of the southern Pannonian Basin. This major paleoenvironmental turnover was forced by syn-rift tectonics in the Pannonian Basin system, which started in the late early Miocene in the Styrian Basin (SE Austria) and ended more than 3 Myr later in the late middle Miocene in the Morava depression (E Serbia).
Nevena Andric Tomasevic
added a research item
The Sarajevo-Zenica Basin of Bosnia-Herzegovina was part of the Dinaride Lake System, a large network of Miocene long-lived freshwater basins in southeastern Europe. The basin contains a thick sedimentary succession of carbonates, coals and mixed siliciclastic deposits that reflects the paleoclimatic and tectonic evolution of the region. In this study, we present novel integrated (magneto-bio)stratigraphic and sedimentological data and reconstruct the paleoenvironmental evolution of the Sarajevo-Zenica Basin during its two main evolutionary phases (thrusting and extension). The basal “Oligo-Miocene” freshwater paleoenvironments are characterized by alternating palustrine, shallow lacustrine and distal fluvial phases. The base level fluctuations are largely controlled by syn-sedimentary pulses of tectonic loading during the final phase of thrusting in the Internal Dinarides. The majority of this succession is considered early Miocene in age, which contrasts with previous Oligocene age estimates. The subsequent extensional phase initiated not later than ~18.4 Ma. This coarsening upward sequence of lacustrine carbonates, silts, sands and conglomerates is correlated between 17.2 and 15 Ma (C5Cr-C5Br) by means of integrated bio-magnetostratigraphy. During this upper extensional phase, subsidence and sediment influx was generally controlled by activity along the basin bounding normal fault, overruling smaller scale climatic influences. We conclude that the existence of the long-lived Sarajevo lake is coeval with other Dinaric and southern Pannonian lakes, and overlaps in time with the Miocene Climatic Optimum. Sedimentation in the Sarajevo-Zenica basin terminated at ~15–14 Ma which concurs with both the end of the climatic optimum as well as the cessation of extension in the Dinarides. These results will help to better quantify the paleoclimatic changes in the Dinaride Lake System as well as the regional tectono-sedimentary events, such as potential migrations of deformation across the Dinarides.
Dan V Palcu
added 2 research items
During the middle Miocene (15-12 Ma), the paleoenvironmental conditions in the Paratethys Sea of Central Europe changed from normal marine to hypersaline and from normal marine to brackish-marine conditions. These paleoenvironmental changes do not consistently correlate to global sea-level curves, indicating other driving mechanisms. Water circulation in the Paratethys strongly depended on two shallow and narrow gateways that were located in tectonically active regions. Here we combine the conservation of water and salt mass with strait-exchange theory to quantitatively link freshwater surface forcing and gateway dimensions to the observed environments. Our model confirms that the proposed sea-level drop of 50-70 m at 13.8 Ma could have restricted the western gateway to the Mediterranean to such an extent that halite formed in the Central Paratethys. Subsequently, the progressive opening of the eastern gateway to the Black Sea led to a decrease in lake level, exposure of the shallow margins, and a reduced surface area in the Eastern Paratethys. This entailed a reduction in water loss to the atmosphere, which, combined with constant river influx, resulted in a positive freshwater budget for the Paratethys proper, and reduced the salinity in the Central Paratethys. This provides a novel physics-based explanation for the change from evaporitic to marine to brackish-marine water conditions in a marginal basin.
Paratethys, the lost sea of central Eurasia, was an anoxic giant during Oligocene – early Miocene (Maikop Series) times. With a size matching the modern-day Mediterranean Sea and a history of anoxic conditions that lasted for over 20 Myrs, the eastern part of this realm (Black Sea-Caspian Sea domain) holds key records for understanding the build-up, maintenance and collapse of anoxia in marginal seas. Here, we show that the collapse of anoxic Maikop conditions was caused by middle Miocene paleogeographic changes in the Paratethys gateway configuration, when a mid-Langhian (Badenian-Tarkhanian) transgression flooded and oxygenated the Eastern Paratethys. We present an integrated magneto-biostratigraphic framework for the early Middle Miocene (Tarkhanian-Chokrakian-Karaganian regional stages) of the Eastern Paratethys and date the lithological transition from anoxic black shales of the Maikop Series to fossiliferous marine marls and limestones of the regional Tarkhanian stage. For this purpose, we selected two long and time-equivalent sedimentary successions, exposed along the Belaya and the Pshekha rivers, in the Maikop type area in Ciscaucasia (southern Russia). We show that a significant but short marine incursion took place during the Tarkhanian, ending the long-lasting Maikop anoxia of the basin. Our magnetostratigraphic results reveal coherent polarity patterns, which allow a straightforward correlation with the time interval 15–12 Ma of the Geomagnetic Polarity Time Scale. The Tarkhanian flooding occurred during a relatively short normal polarity interval that correlates with C5Bn, resulting in an age of 14.85 Ma. The regional Tarkhanian/Chokrakian stage boundary is located within C5ADn at an age of 14.75 Ma and the Chokrakian/Karaganian boundary is tentatively correlated with C5ACn and an age of 13.9–13.8 Ma. Our new Tarkhanian flooding age reveals a paleogeographic scenario that is different from many previous reconstructions. Instead of envisaging marine connections to the Indian Ocean, we show that major changes in connectivity between the Eastern and Central Paratethys seas have caused the influx of marine waters during the Tarkhanian. An increase in marine connectivity with the Mediterranean during a short episode of rapid sea-level rise triggered mixing and ended the widespread anoxia in the Eastern Paratethys. The mixing episode was short-lived (~100 kyr) as the sea-level rise slowed down and connectivity degraded because of tectonic uplift in the gateway area.
Dan V Palcu
added 5 research items
Central Eurasia underwent significant paleoclimatic and paleogeographic transformations during the middle to late Miocene. The open marine ecosystems of the Langhian and Serravallian seas progressively collapsed and were replaced in the Tortonian by large endorheic lakes. These lakes experienced major fluctuations in water level, directly reflecting the paleoclimatic conditions of the region. An extreme lowstand of the Eastern Paratethys lake (‐300 m) during the regional Khersonian stage reveals a period of intensely dry conditions in Central Eurasia causing a fragmentation of the Paratethys region. This period of “Great Drying” ended by a climate change towards more humid conditions at the base of the Maeotian stage, resulting in a large transgressive event that reconnected most of the Paratethyan basins. The absence of a robust time frame for the Khersonian‐Maeotian interval hampers a direct correlation to the global records and complicates a thorough understanding of the underlying mechanisms. Here we present a new chronostratigraphic framework for the Khersonian and Maeotian deposits of the Dacian Basin of Romania, based on integrated magneto‐biostratigraphic studies on long and continuous sedimentary successions. We show the dry climate conditions in the Khersonian start at 8.6‐8.4 Ma. The Khersonian/Maeotian transition is dated at 7.65‐7.5 Ma, several million years younger than previous estimates. The Maeotian transgression occurs later (7.5‐7.4 Ma) in more marginal and shallower basins, in agreement with the time transgressive character of the flooding. In addition, we date a sudden water level drop of the Eastern Paratethys lake, the Intra‐Maeotian Event (IME), at 6.9 Ma, and hypothesize that this corresponds to a reconnection phase with the Aegean basin of the Mediterranean. Finally, we discuss the potential mechanisms explaining the particularities of the Maeotian transgression and conclude that the low salinity and the seemingly “marine influxes” most likely correspond to episodes of intrabasinal mixing in a gradual and pulsating transgressive setting. This article is protected by copyright. All rights reserved.
Werner Schwarzhans
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The fossil record of sciaenid fishes (based on both otoliths and osteological finds) from the Neoge-ne of the Paratethys is reviewed. The species Labrax (=Morone) multipinnatus Gorjanović-Kramberger, 1882 from the Sarmatian of Croatia (Sv. Nedelja) that was originally described as a sea bass of the family Moronidae is reassigned to the extant croaker genus Argyrosomus. Two new genera and species of sciaenid fishes are described based on a single skeleton each, namely Landinisciaena popovi gen. et sp. nov. from the Tarkhanian (Lower/Middle Miocene) North Shir-vanskaya Formation exposed along the Pshekha River, North Caucasus, Russia, and Croatosciaena krambergeri gen. et sp. nov. from the Sarmatian s.s. (Middle Miocene) deposits of Dolje in the nearby of the city of Zagreb, Croatia. The holotype of the former taxon possesses a well-preserved saccular otolith in situ (first record of in situ croaker otolith in Europe) similar to the otoliths of the extant genus Atractoscion. The otolith-based Ottnangian species Atractoscion elongatissimus Schwarzhans, 1993 is transferred to the genus Landinisciaena gen. nov. A comprehensive revision of the Neogene otholith-based sciaenid record from Paratethys resulted in the recognition of three new genera (Chaoia gen. nov., Pontosciaena gen. nov. and Leptosciaena gen. nov.) as well as in the description of a new species L. caputoi sp. nov. from the uppermost Messinian (Lago-mare phase) of Italy. A number of known otholith-based species were either synonymized or assigned to a new generic affiliation. The complex biogeographic history of the Neogene Paratethyan sciaenids (based on both otoliths and skeletal records) is discussed, resulting in the recognition of a vanished "sciaenid bioprovince".
Dan V Palcu
added 3 research items
The Neogene system of seas and lakes of Eurasia, known as the Paratethys realm, is an incomparable natural laboratory to study environmental changes under different geodynamic and climatic conditions. Here, past changes of the marine connections, in conjunction with changes in hydrological budgets and water circulation patterns have repeatedly caused anoxia, hypersalinity, desiccations and catastrophic floods, seriously deteriorating or completely destroying marine biological ecosystems. In studying Paratethys, we have used an integrated stratigraphic approach (paleomagnetic, biostratigraphic and cyclostratigraphic research) to develop an age model, focused on precisely timing the events that led to the major changes of the marine, brackish and lacustrine environments. By precisely timing the Badenian-Sarmatian Extinction Event (BSEE), the largest extinction event in the history of the system of seas and lakes of Eurasia, we link this catastrophic event to a change in the nature of the water exchange in the gateways that connect the Eurasian seas. This natural experiment provides insights on the sensitivity of the marine connections and the effects on the dynamics of the bio-chemistry of interacting marine ecosystems.
Throughout the Late Neogene, the Black Sea experienced large paleoenvironmental changes, switching between (anoxic) marine conditions when connected to the Mediterranean Sea and (oxic) freshwater conditions at times of isolation. We create a magnetostratigraphic time frame for three sites drilled during Deep Sea Drilling Project (DSDP) Leg 42B to the Black Sea (drilled in 1975). At the time, magnetostratigraphic dating was impossible because of the presence of the little understood iron sulfide mineral greigite (in sediments a precursor to pyrite) as magnetic carrier. Our rock-magnetic results indicate that only anoxic conditions result in poor magnetic signal, likely as a result of pyrite formation in the water column rather than in the sediment. The magnetostratigraphic results indicate that Hole 379A, drilled in the basin center, has a continuous sedimentary record dating back to 1.3 Ma. Hole 380/380A is subdivided into three consistent intervals, 0-700 mbsf, 700-860 mbsf and 860-1075 mbsf. The top unit covers the Pleistocene but the magnetostratigraphy is likely compromised by the presence of mass transport deposits. The middle unit spans between 4.3 and 6.1 Ma and records continuous deposition at ~10 cm/kyr. The lower unit lacks the independent age constraints to correlate the obtained magnetostratigraphy. Hole 381 is drilled on the Bosporus slope and as a result, hiatuses are common. A correlation to the nearby Hole 380/380A is proposed, but indicates deposits cannot straightforwardly be traced across the slope. Our improved age model does not support the original interpretation based on these cores of a desiccation of the Black Sea during the Messinian salinity crisis.
Ljupko Rundić
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Sediments of the Middle and Late Miocene (about 16-5.3 Ma) are widespread in the area of Avala Mt. and its vicinity. As a rule, they contain abundant and diverse fossilized representatives of macro and micro fauna that existed during the Middle Miocene in the Paratethys (Rakovica stream, Leštane, Torlak, Kumodraž, Zavojnica River valley, Vrčin). Rich fossil assemblages consist mainly of algae, foraminifers, ostracods, mollusks, corals, bryozoans, echinoderms and crabs as well as otoliths and jaws of fish. Although marine organisms are not found in the Late Miocene sediments, there are numerous and diverse representatives of endemic fauna from the ancient Lake Pannon. The most important sites of Middle and Late Miocene deposits are located at the Torlak hill, in Vrčin, Zuce, Karagača, Beli Potok and Konopljište. They are significant not only for the stratigraphic--paleontological studies, paleogeographic and geodynamic reconstructions during the Miocene but also as valuable geodiversity and geoheritage objects.
Predrag Radović
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There was a fauna of baleen whales (Cetacea: Mysticeti) in the Central Paratethys, a Miocene water body which covered the area of present-day Central Europe. Most of the fossil baleen whales from the Central Paratethys have been found in strata assigned to the regional Badenian age and comprise endemic forms, known only from this region. Here a new description is provided for a fragmentary skeleton of a whale found in Belgrade, Serbia, and its age context and biological aspects are discussed. This specimen, consisting of a fragmentary horizontal ramus of the mandible and eight caudal vertebrae, is tentatively identified as ?Parietobalaena sp., a globally known Miocene taxon, with related forms having been recorded earlier from the Eastern Paratethys. An early Sarmatian age (i.e., about 12.7-12.4 Ma) is proposed for the specimen. Based on epiphyseal fusion of caudal vertebrae, the specimen’s age is identified as a subadult, with a body length of around 2.5 m and an estimated adult body length around 3-3.5 m, which is extremely small for baleen whales. This find represents one of the latest records of baleen whales in the Central Paratethys and one of the latest published records of Parietobalaena-like taxa in the world.
Dan V Palcu
added a project reference
Dan V Palcu
added a project reference
Annique van der Boon
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During the Eocene-Oligocene transition (EOT), a major palaeoenvironmental change took place in the Paratethys Sea of central Eurasia. Restricted connectivity and increased stratification resulted in wide-spread deposition of organic-rich sediments which nowadays make up important hydrocarbon source rocks. The North Alpine Foreland Basin (NAFB) was a major gateway of the Paratethys Sea to the open ocean during the Eocene, but the age of closure of this gateway is still uncertain. The Ammer section in southern Germany documents the shallowing of this connection and subsequent disappearance of marine environments in the NAFB, as reflected in its sedimentary succession of turbidites to marls (Deutenhausen to Tonmergel beds), via coastal sediments (Baustein beds) to continental conglomerates (Weißach beds). Here, we apply organic geochemistry and date the lithological transitions in the Ammer section using integrated stratigraphy, including magnetostratigraphy and biostratigraphy. Nannoplankton and dinocyst results can be reconciled when dinoflagellate species Wetzeliella symmetrica is of late Eocene age. Our magnetostratigraphy then records C13r-C13n-C12r and allows calculation of sediment accumulation rates and estimation of ages of lithological transitions. We show that the shallowing from turbiditic slope deposits (Deutenhausen beds) to shelf sediments (Tonmergel beds) coincides with the Eocene-Oligocene boundary at 33.9 Ma. The transition to continental sediments is dated at ca. 33.15 Ma, significantly older than suggested by previous studies. We conclude that the transition from marine to continental sediments drastically reduced the marine connection through the western part of the NAFB and influenced the oxygen conditions of the Paratethys Sea.
Werner Schwarzhans
added a research item
The early Badenian represents the last period of unrestricted marine connectivity with adjacent oceans in the history of the Paratethys. A comprehensive capture of the fish fauna roaming the early Badenian seas of the Paratethys is necessary to fully comprehend the endemic evolution that took the stage following its isolation during the Serravallian (late Badenian in the Central Paratethys and Karaganian and Konkian in the Eastern Paratethys). Many publications have dealt with early Badenian otolith-based fish assemblages in the northern and western parts of the Central Paratethys, but coeval faunas from the southeastern Central Paratethys and the Eastern Paratethys are scarce and in dire need of revision. Here I present a review of the rich otolith assemblage described by Weiler in 1950 from the early Badenian of Coşteiu de Sus and Lăpugiu de Sus in Romania and update their identifications. The review results in the recognition of a number of new species, i.e. Aulopus costeiensis n. sp., Bathypterois solidus n. sp., Myripristis lobata n. sp., Lesueurigobius magniiugis n. sp., Weilerigobius lapugiensis n. gen., n. sp., Callanthias transylvanicus n. sp. and Pagellus schuberti n. sp. A comparison with the well known otolithbased fish faunas from the northern and western Central Paratethys reveals good correlation, but nearly one quarter of all fish species are not recorded from there. The most likely explanation of this phenomenon is a latitudinal / climatic difference and probably a greater influence of Eastern Paratethyan elements in Romania. A much smaller collection from Badenian equivalent strata of wells in Bulgaria, inherited from B. Strashimirov, was also studied. It contained the first fossil record of the gobioid family Microdesmidae - Microdesmus paratethycus n. sp. This collection is dominated by very small otoliths that appear to have been collected in the course of search for microfossils and hence shows many small fish representatives missing from the Romanian locations. The role of collecting bias versus potential faunal differences is discussed with this example. It is concluded that the knowledge of the early Badenian otolith-based fish fauna of the Central Paratethys is much improved, albeit far from being completely assessed. Important additional data, however, are more likely to be expected from coeval Eastern Paratethyan strata when comprehensively collected and older material being reviewed, if still available.
Dan V Palcu
added 3 research items
Aims: The marine gateways are an important element in the geographic and paleogeographic architecture of oceans and seas. They influence the heat and chemical exchange between neighboring water bodies, mixing or segregating them and influencing the climate and the ecosystems. In extreme configurations, they contribute to the formation of evaporites, faunal turnovers or onset of extinction events. However, the geologic records in the areas of the gateways are poorly preserved and detailed information on the sensitivity, functioning and the significance of the gateways remains scarce. To counter the lack of reliable records in the area of the gateways, our approach is to focus our research on the study of the records from seas adjacent to problematic gateways, already identified as potential triggers of major environmental catastrophes. Methods & Results: We study the accessible, well-exposed marine sediments from basins that belonged to the Neogene system of seas and lakes of Eurasia (Paratethys). We focus on an area close to the Barlad strait, which during the Middle Miocene has connected the Central and Eastern Paratethys. Integrated magneto-bio-stratigraphy, in the sub-basins that mirror the Barlad Strait, has allowed high-resolution correlations between Central and Eastern Paratethys segments that are in the vicinity of the gateway. Ecosystems collapse and significant faunal losses occur at synchronously east and west of the gateway 12.65 Ma ago. Further geochemical and mineralogical analyses confirm a significant modification of the exchange mechanism between Central and Eastern Paratethys but reveal that the chain of events differs greatly east and west of the strait. Conclusions: The environmental catastrophes that occurred 12.65Ma in Central and Eastern Paratethys are interpreted as the results of a significant reconfiguration of the Barlad strait. The strait increased its size and switched from inefficient, with limited water exchange, to a "pump" where the density contrast between the two seas accelerated the water exchange. The exchange of waters with different chemistries led to extinctions on both sides of the gateway ending the Konkian and Badenian seas and replacing them with the new Sarmatian fauna. From the global point of view, the activation of the gateway correlates with a relatively small sea-level rise (<10m) and occurs in a context of tectonic subsidence of the gateway zone. The fact that such small changes in the sea level can influence the behavior of the gateway so greatly, raises questions on the behavior of marginal seas such as the Black sea in the near future the context of the projected sea-level rises.
Annique van der Boon
added a research item
Since the late Eocene, convergence and subsequent collision between Arabia and Eurasia was accommo-dated both in the overriding Eurasian plate forming the Greater Caucasus orogen and the Iranian plateau, and by subduction and accretion of the Neotethys and Arabian margin forming the East Anatolian plateau and the Zagros. To quantify how much Arabia–Eurasia convergence was accommodated in the Greater Caucasus region, we here provide new paleomagnetic results from 97 volcanic sites (∼500 samples) in the Talysh Mountains of NW Iran, that show ∼15◦net clockwise rotation relative to Eurasia since the Eocene. We apply a first-order kinematic restoration of the northward convex orocline that formed to the south of the Greater Caucasus, integrating our new data with previously published constraints on rotations of the Eastern Pontides and Lesser Caucasus. This suggests that north of the Talysh ∼120km of convergence must have been accommodated. North of the Eastern Pontides and Lesser Caucasus this is significantly more: 200–280km. Our reconstruction independently confirms previous Caucasus convergence estimates. Moreover, we show for the first time a sharp contrast of convergence between the Lesser Caucasus and the Talysh. This implies that the ancient Paleozoic–Mesozoic transform plate boundary, preserved between the Iranian and East-Anatolian plateaus, was likely reactivated as a right-lateral transform fault since late Eocene time.
Annique van der Boon
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The transition from the Bartonian to the Priabonian, as traditionally understood, has long been associated with a series of extinctions and originations in several microfossil groups. The planktonic forami-nifer genus Morozovelloides and large species of Acarinina suffered a rapid global extinction, as did many radiolarians. Calcareous nannofossils show several assemblage changes including the acme beginning of Cri-brocentrum erbae and the lowest and highest occurrences of Chiasmolithus oamaruensis and C. grandis respectively. In shallow water environments, larger foraminifera also show an extinction among large species of Nummulites, as well as the first occurrences of the stratigraphically important genus Spiroclypeus. However , the correlation between shallow and deep water records remains uncertain, as do the mechanisms driving these biotic events. Here we present the results of a new integrated stratigraphical study (calcareous nanno-fossils, planktonic foraminifera, larger benthic foraminifera, and low-resolution magnetostratigraphy) of the Urtsadzor section in southwestern Armenia which appears to be continuous through this interval. The Urt-sadzor section consists of calcareous siltstones rich in micro-and nannofossils, with interbedded limestones containing abundant larger benthic foraminifera. Our new data enable us to correlate larger foraminiferal events with global plankton biostratigraphy, in a section outside of southwest Europe where most previous correlations have been based. At Urtsadzor, the large Nummulites species of N. millecaput-group are present throughout the whole section but decrease in abundance toward the top. The first occurrence of Spiroclypeus, also occurs in the upper part of the section, marking the SBZ 18/19 boundary. These events are associated with the phylogenetic development of the Nummulites fabianii and Heterostegina reticulata lineages. However , the calcareous plankton biostratigraphy indicates the section is well within the Priabonian; within plank
Dan V Palcu
added a research item
Marine gateways prove to be important factors for changes in the ecology and biochemistry of marginal seas. Changes in gateway configuration played a dominant role in the Middle Miocene paleogeographic evolution of the Paratethys sea that covered Central Eurasia. Here, we focus on the connection between the Central (CP) and Eastern Paratethys (EP) to understand the paleoenvironmental changes caused by the evolution of this marine gateway. We first construct an integrated magneto-biostratigraphic framework for the late Langhian-Serravallian (Chokrakian-Karaganian-Konkian-Volhynian) sedimentary record of the eastern domain, which allows a correlation to the well-dated successions west of the gateway. The magneto-biostratigraphic results from the Zelensky-Panagia section on the Black Sea coast of Russia show that the Chokrakian/Karaganian boundary has an age of 13.8 Ma, the Karaganian/Konkian boundary is dated at 13.4 Ma, and the Konkian/Volhynian boundary at 12.65 Ma. We identify three major phases on gateway functioning that are reflected in specific environmental changes. During the Karaganian, the EP turned into a lake-sea that supplied a unidirectional flow of low-salinity waters to the west, where the CP sea experienced its Badenian Salinity Crisis. This configuration is remarkably similar to the Mediterranean during its Messinian Salinity Crisis. The second phase is marked by a marine transgression from the west, reinstalling open-marine conditions in the CP and causing marine incursions in the EP during the Konkian. The Volhynian is characterized by a new gateway configuration that allows exchange between CP and EP, creating unified conditions all over the Paratethys. We hypothesize that a density driven pumping mechanism is triggered by the increase in connectivity at the Konkian/Volhynian boundary, which simultaneously caused major paleoenvironmental changes at both sides of the gateway and led to the Badenian-Sarmatian extinction event in the CP.
Dan V Palcu
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PARATETHYS-MEDITERRANEAN INTERACTIONS - ENVIRONMENTAL CRISES DURING THE NEOGENE
Dan V Palcu
added a research item
The marine gateways are an important element in the geographic and paleogeographic architecture of oceans and seas. They influence the heat and chemical exchange between neighbouring water bodies, mixing or segregating them and influencing the climate and the ecosystems. In extreme configurations, they play a role in the onset of Salinity Crises and the formation of evaporites. However, detailed information on the sensitivity and functioning of gateways remains scarce as their geological records are poorly preserved. To counter the lack of reliable records in the gateways the focus of our research shifted on the impact of the gateways on the adjacent seas. We rely on the study of the more accessible, better-exposed marine sediments from basins that belonged to the Neogene system of seas and lakes of Eurasia (Paratethys). Integrated magneto-bio-stratigraphy in these basins has provided high-resolution correlations between the neighbouring seas within Paratethys, which, in turn, led to the identification of problematic paleogeographic configurations. Here we focus on two such configurations: the first provides the setting for evaporite formation while the second sets in motion a water mixing mechanism that leads to extinctions.
Dan V Palcu
added 2 research items
The Miocene epicontinental Paratethys Sea of central Eurasia has experienced multiple restriction and reconnection events to the open ocean. Magnetostratigraphy is an important dating tool to better understand the temporal and spatial paleoenvironmental variations associated with these changes. Magnetostratigraphy in the Paratethys domain, however, is complicated by the presence of greigite (Fe3S4). Here, we report rock magnetic and X-ray fluorescence data of the Tisa section (Romania) which was previously magnetostratigraphically dated at the middle Miocene (base at 12.8 Ma and top at 12.2 Ma). This section comprises the Badenian Sarmatian Extinction Event (BSEE), which is marked by a major salinity change from marine to brackish environments, related to the opening of the connection between the Central and the Eastern Paratethys basins. In the marine Badenian sediments below the BSEE, the pyritization process is shown to be complete because of abundant sulfate supply. In the brackish Sarmatian deposits, four intervals with early diagenetic greigite are observed, and linked to insufficient sulfate in the water column. These four greigite intervals appear to correspond to maxima in the ∼100 kyr eccentricity cycle. We propose that increased fresh water from the Eastern Paratethys basin during eccentricity maxima restricted the sulfate availability in the Tisa area, leading to a reduced HS- production and enhanced greigite preservation. The early diagenetic formation of greigite enables a quasi syn-depositional recording of the paleomagnetic field, which allows reliable paleomagnetic dating in this section. Our results further suggest greigite as a potential indicator for salinity changes during marine/brackish transitions.
The Miocene palaeogeographic evolution of the Paratethys Sea is still poorly constrained. Here, we use modern Mediterranean biochronology to provide an up-to-date overview of changing seas in Central Europe. Instead of a Paratethys sea that waxed and waned with fluctuating global sea level, we show that the evolution of different seas was mainly controlled by tectonic phases. The Early Miocene “Ottnangian Sea” (~18 Ma) was connected to the Mediterranean via the Rhône valley, while the “Karpatian Sea” (~16.5 Ma) was initiated by a tectonically induced marine transgression through the Trans-Tethyan gateway. In most Central European basins the establishment of the “Badenian Sea” (<15.2 Ma), triggered by subduction-related processes in the Pannonian and Carpathian domain, is significantly younger (by ~1 Myr) than usually estimated. The updated palaeogeographic reconstructions provide a better understanding of the concepts of basin dynamics, land–sea distribution and palaeoenvironmental change in the Miocene of Central Europe. This article is protected by copyright. All rights reserved.
Werner Schwarzhans
added 2 research items
Gadid otoliths are among the most common otoliths in the Neogene of Europe. To date, these have been recorded in situ and therefore correlated with the skeletal record only in two cases, Paratrisopterus avus and Palimphemus anceps. Here, we describe otoliths in situ from three gadiform taxa from the Sarmatian of the Central Paratethys—Palimphemus macropterygius, Paratrisopterus caspius and Enchelyopus susedanus. A number of specimens previously described by Kramberger (Paläontol. Österr. -Ungar. und des Orients 3:65–85, 1883) and Andjelković (Glas. Prir. Muz. A 24:127–154, 1969) are revised. Kramberger’s Morrhua macropterygia is reassigned to the extinct gadid genus Palimphemus; moreover, Morrhua lanceolata is considered a junior synonym of P. anceps Kner 1862. All the Palimphemus specimens studied from the Sarmatian of the Central Paratethys belong to P. macropterygius, while P. anceps does not seem to be present in the Paratethys after the late Badenian/Konkian. The otolith-based species Palimphemus minusculoides (Schubert 1912) is considered as a junior synonym of P. macropterygius. Paratrisopterus caspius is regarded as a senior synonym of P. avus Fedotov 1971, whose otoliths in situ were previously described by Fedotov (1976). The new data allow further synonymization of otolith-based species, such as P. insectus (Weiler 1943) and possibly also P. irregularis (Gaemers 1973). Moreover, Properca sabbai Pauca 1929 is removed from the faunal list of Sarmatian fishes in the Paratethys. Kner’s Brosmius susedanus is reassigned to the extant lotid genus Enchelyopus, with Brosmius elongatus Kramberger 1883 representing a junior synonym. There is no record of isolated otoliths correlating with E. susedanus in the literature; however, a number of previously undescribed specimens of E. susedanus have been identified from the middle Sarmatian s.l. of Jurkino, Crimea.
Predrag Radović
added a research item
The palaeoecology of fossil molluscs of Serbia is insufficiently studied. Drilling predation indicates interactive relationships among Middle Miocene Badenian molluscs from the Rakovica sands. These sands are present in the Rakovica stream valley (southern part of Belgrade), and well-known data about the fauna has existed since the end of the XIX century. The collected material (one bulk sample) from the sec tion was used for studies that included 2301 shells of molluscs (1617 of gastropods and 684 of bivalves). Among them were specimens with predatory drill holes. Determining the value of drilling frequency (DF) and prey effectiveness (PE) facilitates identification of the relationship between shell-drilling predators and their prey. Based on analysis of the overall association, carnivorous gastropods were do minant in the sample, comprising more than fifty percent (52.32%) of all gastropod specimens. In addition, they constitute a large percentage of the total sample (43.19%). The largest number of victims was observed among bivalves, which are indicated by a DF of 16.96%. The results were compared with other localities of Miocene age in Paratethys and with studies on the Miocene sediments from the Boreal and the Atlantic Provinces. These comparisons show that PE and DF are very similar to results from the Central Paratethys, but that they are significantly higher than in the other are as mentioned.
Annique van der Boon
added 2 research items
The Greater Caucasus, extending from the Black Sea in the West to the Caspian Sea in the East, is the world's second largest active collisional orogen. It differs from traditional orogens in its relatively short length (~1100km) and its location >350 km away from a plate boundary (Arabia-Eurasia). Causes for its formation since the Late Eocene are still enigmatic – although the Arabia-Eurasia collision plays an important role in its evolution. Estimating how much convergence has been accommodated in the Greater Caucasus is key to understanding how Arabia-Eurasia convergence has been partitioned across the plate boundary zone. However, due to the inaccessibility of the region and poor exposure, little is yet known on the structure of the Caucasus. We present the results of a paleomagnetic study of 97 sites in Eocene rocks of NW Iran to constrain the vertical axis rotation history between the Alborz Mountains and the eastern Lesser Caucasus. We combine this with published data from the Lesser Caucasus and eastern Pontides as input for a kinematic restoration of the orocline. Since evidence from the Greater Caucasus suggests a late Eocene onset for its uplift and exhumation, we focus on reconstructing the rotation of the orocline since the Eocene and find that the Talesh in NW Iran rotated ~30° CW since the Eocene, alongside ~30° CCW in the eastern Pontides, with the Lesser Caucasus not undergoing significant rotations. Restoring the rotated limbs requires a southward restoration of the Lesser Caucasus. Our preliminary estimates of the convergence in the Greater Caucasus range between 100 and 300 kilometres, which narrows the range of 100-900km suggested in literature.
Dan V Palcu
added 2 research items
The Badenian-Sarmatian Extinction Event (BSEE) is considered the strongest turnover event in the history of Paratethys (Piller et al. 2007). It marks the disappearance of open marine ecosystems that are replaced by brackish and freshwater environments. The cause of the BSEE is considered to be the restriction of the connections with the open ocean in the Central Paratethys (Rogl1999). We use a integrated stratigraphic approach on key sections the Carpathian Foredeep / Dacian Basin, Romania. We date the event at 12.65Ma. This age model for the BSEE shows a disagreement with the correlations previously used to date this boundary, suggesting a different, probably local tectonic, trigger for the BSEE. The result raises questions about the relevance of the transgression-regression cycles in the dating of some other regional stratigraphic stages of the Paratethys.
The Badenian–Sarmatian boundary interval is marked by a major extinction event of marine species in the Central Paratethys. The exact age of the boundary is debated because many successions in marginal basins show erosional features and fauna reworking at the boundary level. Here, we selected the Tisa section in the Carpathian foredeep basin of Romania, which is continuous across this Badenian–Sarmatian Extinction Event (BSEE). Quantitative biostratigraphic records of planktic and benthic foraminifera and calcareous nannofossils allow to accurately locate the Badenian–Sarmatian boundary and indicate a major paleoenvironmental change from open marine to brackish water conditions. Magnetostratigraphic results reveal a polarity pattern that uniquely correlates to the time interval between 12.8 and 12.2 Ma. Interpolation of constant sedimentation rates determines the age of the BSEE in the Carpathian foredeep at 12.65 ± 0.01 Ma, in good agreement with several earlier estimates. We conclude that the extinction event took place in less than 10 kyr, and that it was most likely synchronous across the Central Paratethys. It corresponds to a major paleogeographic change in basin connectivity with the Eastern Paratethys, during which the nature of the Barlad gateway switched from a passive to a full connection.
Ljupko Rundić
added an update
Werner Schwarzhans
added 6 research items
In the final section of our series of studies on Sarmatian fishes from the Paratethys with otoliths in situ, we deal with three pleuronectiform species. Each species is re-defined based on the type material plus additional specimens not previously described. Their generic allocation has been reviewed. Two of these species belong to the Bothidae: Arnoglossus bassanianus (Kramberger 1883) and Bothus parvulus (Kramberger 1883). The third species was originally described as Rhombus serbicus Anđelković 1966 and is now placed within the Soleidae. It is placed herein with the newly established fossil genus Parasolea, which is thought to be related to the extant Solea and Vanstraelenia and is considered to represent an extinct endemic Paratethyan taxon. Two of the three species described herein can be linked to isolated otoliths. The otolith-based species—Arnoglossus? tenuis (Schubert 1906)—is synonymized with a skeleton-based species—Arnoglossus bassanianus (Kramberger 1883). Isolated otoliths and comparison with related extant species indicate that the species described here must have reached sizes of at least twice those of the largest articulated skeletons.
The studies presented in this special issue describe and evaluate otoliths in situ in 18 species of extinct Paratethyan fishes, 17 from Sarmatian, and one from Karaganian deposits. Together with previously described fishes from the area with otoliths in situ and additional works which we are aware of being in progress, this time interval has now yielded 34 fish species with otoliths in situ, approximately equivalent to one-third of the entire Sarmatian fish fauna of the Paratethys known to date. Therefore, it represents by far the most diverse fossil fish fauna with otoliths in situ. The implications of the linking of skeletal and otolith data are briefly discussed as well as the prospects for future research. The anecdotal history of the formation of the work group which became engaged in these studies is presented.
Ljupko Rundić
added 9 research items
In this paper we establish when and how the Pannonian basin and associated Central Paratethys basins were isolated from the remainder of the Paratethys, a system of back-arc basins and inland seas that once extended over a large part of Europe. The isolation, which occurred at the beginning of the Late Miocene, is marked by a paleoenvironmental change from marine to fresh water conditions that caused the regional Sarmatian–Pannonian Extinction Event. It also had significant paleogeographical implications for the basin fill and for sedimentary transport across the Carpathian Mountains. The exact age of and cause for the isolation are still subject to debate. Here, we use magnetostratigraphic dating coupled to ostracod and mollusc biostratigraphy to establish the isolation age of the Pannonian basin. We dated the isolation of the Pannonian basin at 11.63 ± 0.04 Ma in a section on the northern flank of the Fruška Gora inselberg (northern Serbia). This age is in line with recent results from the Vienna basin but predates the isolation of the Transylvanian by 0.33 Myr, suggesting that isolation took place in two steps. We conclude that the uplift of the Carpathian Mountains caused the isolation but that eustatic sea level fluctuations may have had a minor influence as well.
The deformation chronology of the margins of the south-eastern and north-western Eisenstadt–Sopron sub-basin, initially (i) the multiphase normal faulting convergence with the sediment stacking, tectonic inversion and eroded rock volumes were characterised and subsequently (ii) the effects of these processes on the local, spatially confined coal bearing mini-petroleum system were additionally reproduced and quantified. The deformations in the south-eastern margin of the Basin indicated a late Sarmatian - Pannonian development of fault-adjacent reverse drag as potentially the main trap formation time. A combination of ‘palaeo’ and ‘present day heat flow scenarios was used for the calculation of hydrocarbon generation within the north-western depocentre accommodated by the initial early Tertiary syn-rift stretching and syn-sedimentary deposition associated with the Forchenstein fault. According to a palinspastic analysis, deformation chronology and thermal basin models, hydrocarbon generation commenced during the Middle Miocene at about 14 Ma and terminated during the Late Miocene (≈ 10 Ma) due to a rapid cooling caused by uplift and erosion. Over 50% of the total resource potential was realized at the deepest mini-basin section. The results of 1D basin modelling of the north-western mini-basin depocentre suggested that there is a high probability of once active source rocks around a depocentre, however with limited generation volumes
We describe here the first fossil otoliths from the Middle Miocene (Badenian and Sarmatian) of Belgrade, Serbia. They were obtained from Lower Badenian outcrops at Slanci and from upper Badenian and Sarmatian sediments recovered from four shallow wells near the village of Barajevo. The otoliths from the Lower Badenian of Slanci represent fishes typical for an open marine environment, characterized primarily by the mesopelagic families Myctophidae and Bregmacerotidae, a faunal composition that is also well known from other time equivalent locations in the Central Paratethys. The upper Badenian and Sarmatian composition of the fish fauna, in contrast, is dominated by otoliths of the family Gobiidae, indicating a sharp environmental shift from open marine to shallow water, probably slightly brackish environments, which is also confirmed by the faunal composition of mollusks, foraminifera, and ostracods. Most of the gobiid genera identified in the samples from Barajevo represent small fishes of the so-called sand gobies with Ponto-Caspian affinities, such as Economidichthys, Knipowitschia, or Pomatoschistus, or are entirely endemic to the Ponto-Caspian Basin, such as Hyrcanogobius. Another group of endemic Ponto-Caspian gobies is the first fossil record interpreted to represent the genus Proterorhinus. These and other finds currently being investigated indicate that the origin of the extant, rich, endemic gobiid fauna of the Ponto-Caspian Basin dates back to a crucial time in the development of Paratethys during the Middle Miocene when it segregated from the Mediterranean with the onset of phases of low salinity in the basin. In addition, we briefly discuss the distribution of certain gobiid species during Late Badenian and Sarmatian as it begins to emerge. The following new taxa are described based on fossil otoliths: Hyrcanogobius hesperis n.sp. and Proterorhinus vasilievae n.sp.