16 research outputs found
Late Messinian palynoflora from Central Anatolian Plateau (Çankırı Basin)
ABSTRACTWithin the framework of the Marie Curie FP7-PEOPLE-2013-ITN program, the ALErT project targets on tectonic and climatic boundary conditions in the regions along the densely populated in the Central Anatolian Plateau and the associated with natural hazards. The Central Anatolian Plateau (CAP) extends in a wide area in between zone the Aegean extensional zone and Bitlis /Zagros compressional zone. The Çankırı Basin was opened in Late Cretaceous between the Kırşehir block in the south and Sakarya continents in the north in central Anatolia. During the Neo-Tethys closure, the history of the basin became a large intermontane basin which covered with continental sedimentary environments (Kazancı et al., 1999). During the Late Miocene, there were different types of lacustrine environments in between the northern and southern parts. Age evidence of the Çankırı Basin has been obtained from the European mammalian faunal zones, because of the fact that Sr analysis results has not be significant to interpreted age (Mazzini 2015) and based on this, the late Messinian age Bozkır Formation and the Plio – Quaternary Değim Formation have seasonally dominant aridity. To figure out the paleoenvironmental and palaeoclimate changes in Çankırı Basin were analyzed Biotic (Paynology) and abiotic proxy data (geochemical, δ18O - δ13C isotopes analyses and CaCO3). Fifteen samples from Hancili Formation, Tuglu Suleymanli crossing border, Bozkır Formation and Değim Formation were collected from claystone, dark silty clay, gypsum and breccia with silty gypsum layers in the Çankırı Basin. The samples were treated standard palynological procedures described by Cour (1974). For pollen step all samples, residues, and slides are stored in Comenius University in Bratislava, Slovakia. Pollen grains for each sample were accounted 150 pollen grains, without Pinus in the Çankırı Basin. Pollen identification was performed under a Zeiss light microscope, and under a Quanta FEG250 Scanning electron microscope (SEM) used for high resolution imaging of pollen grains in Institute of Electrical Engineering Slovak Academy of Sciences. The pollen diagram was prepared with Tilia*Graph (2.0) (http://www.chrono.qub.ac.uk/datah/tilia.html).According to Mosbrugger and Utescher (1997); coexistence approach derived quantative paleoclimate parameters. To explain the ecological characteristic, we used version of the Past 3.x- the Past of the Future free software scientific statistical data analysis program (http://folk.uio.no/ohammer/past/). Head map was prepared with this program for four formations. Palynological data by evaluating head map, the uplift during the Late Messinian in Çankırı Basin has been confirmed. To illustrate for those vegetational composition, we applied Xact 8 for the graphic presentation. According to Traverse (1978) developed Steppe-Forest Index using a ratio of appropriate species of pollen, that save as a climatic indicator (warm to cold) on the other hand interpretation of aridity we follow Cour & Duzer (1978). As a consequence, the Poaceae/total Asteraceae ratio in a pollen diagram can be used as a climate index used Poaceae /Asteraceae ratio to find out dry to wet zones lines (Popescu, 2006) and it was calculated based on palynological results (using cluster analysis) show four climate cycles with three dry periods. Based on those calculations we confirmed long term cooling trend during Late Messinian to Plio-Pleistocene in Çankırı Basin. In most pollen spectra are mainly presented by Asteraceae, Chenopodiaceae, and Poaceae and by trees with Pinus, Cathaya, and Fagus. The group of herbs is important in the pollen sum and mainly consist of Poaceae, Chenopodiaceae and Asteraceae, which document open grassland type of vegetation with warm – temperate climate.
40Ar/39Ar geochronology of Burdigalian paleobotanical localities in the central Paratethys (south Slovakia)
The Lipovany and Mučín paleobotanical localities contain important floral associations within the tuff horizons, which were used for determination of subtropical to tropical climatic conditions during the Early Miocene. Based on the combination of results from plagioclase and biotite 40Ar/39Ar dating, the age of the tuff deposition is around 17.3Ma. For the Lipovany locality, single-grain 40Ar/39Ar convergent ages of 17.49±0.54Ma and 17.28±0.06Ma, for plagioclase and biotite were obtained, respectively. The Mučín locality only provide an imprecise convergent age of 16.5±1.4Ma due to the small size of the analyzed plagioclase crystals. The results thus allowed to include the fossil subtropical flora of the studied localities in the late Ottnangian regional stage (upper part of the Burdigalian). Additionally, these age data indicate that deposition of the overlaying Salgótarján Formation starts much later than originally thought (during Ottnangian-Karpatian boundary)
Evolution of depositional systems and sedimentary cycles in Želiezovce Depression of the Danube Basin
Five deep wells (Pozba4, Pozba3, Dubnik1, Nová Vieska1, Modrany1), drilled in the Želiezovce depression of the south-east Danube Basin penetrate the Cenozoic sedimentary record in overall thickness ranging from 1000 m up to 3000 m, the total thickness gradually increases from South to the North. This area is well known for the complex geological structure related to the Central Western Carpathians and Transdanubian Range junction along the Hurbanovo – Diösjenö line. Many authors have studied this area in the past, nevertheless Depositional systems, sedimentary cycles and the development of sedimentary facies were never understood in detail. The Re-evaluation of biostratigraphy, paleoecology, sedimentology and the Re-interpretation of e-logs ware all incorporated into well correlations, what resulted in definition of four main sedimentary cycles: (1) The Lowermost Oligocene cycle, consisting of mudstones with occasional sandstone intercalations, associated with slope to offshore marine environment what is supported by the presence of the NP 22 calcareous nannoplankton zone. (2) The transgressive Langhian (Lower Badenian) deposits, composed of mudstones with epiclastic volcanic material and tuffite beds ware associated with shelfall to offshore environement the age is supported by the NN4 - NN5 calcareous nannoplankton zone. (3) The Serravallian (Upper Badenian - Sarmatian) cycle is composed mainly by mudstones with abundant Lithothamnium fragments associated with brackish coastal pain environment, supported by the NN6 calcareous nannoplankton zone and by the mass occurrence of fish scales and Ervilia dissita (Eichwald) bivalves. (4) The overlying strata are represent the Tortonian-Pliocene (Pannonian-Pliocene) cycle, consists mostly from claystone which are overlain by sandstone and siltstones layers is associated with lake, deltaic and alluvial plain environment.
Lower Miocene plant assemblage with coastal-marsh herbaceous monocots from the Vienna Basin (Slovakia)
A new plant assemblage of Cerová-Lieskové from Lower Miocene (Karpatian) deposits in the Vienna Basin (western Slovakia) is preserved in a relatively deep, upper-slope marine environment. Depositional conditions with high sedimentation rates allowed exceptional preservation of plant remains. The plant assemblage consists of (1) conifers represented by foliage of Pinus hepios and Tetraclinis salicornioides, a seed cone of Pinus cf. ornata, and by pollen of the Cupressaceae, Pinaceae, Pinus sp. and Cathaya sp., and (2) angiosperms represented by Cinnamomum polymorphum, Platanus neptuni, Potamogeton sp. and lauroid foliage, by pollen of Liquidambar sp., Engelhardia sp. and Craigia sp., and in particular by infructescences (so far interpreted as belonging to cereal ears). We validate genus and species assignments of the infructescences: they belong to Palaeotriticum Sitár, including P. mockii Sitár and P. carpaticum Sitár, and probably represent herbaceous monocots that inhabited coastal marshes, similar to the living grass Spartina. Similar infructescences occur in the Lower and Middle Miocene deposits of the Carpathian Foredeep (Slup in Moravia), Tunjice Hills (Žale in Slovenia), and probably also in the Swiss Molasse (Lausanne). This plant assemblage demonstrates that the paleovegetation was represented by evergreen woodland with pines and grasses in undergrowth, similar to vegetation inhabiting coastal brackish marshes today. It also indicates subtropical climatic conditions in the Vienna Basin (central Paratethys), similar to those implied by other coeval plant assemblages from Central Europ
Biostratigraphy, sedimentology and paleoenvironments of the northern Danube Basin: Ratkovce 1 well case study
The Ratkovce 1 well, drilled in the Blatné depocenter of the northern Danube Basin penetrated the Miocene sedimentary record with a total thickness of 2000 m. Biostratigraphically, the NN4, NN5 and NN6 Zones of calcareous nannoplankton were documented; CPN7 and CPN8 foraminifer Zones (N9, 10, 11 of the global foraminiferal zonation; and MMi4a; MMi5 and MMi6 of the Mediterranean foraminiferal zonation were recognized. Sedimentology was based on description of well core material, and together with SP and RT logs, used to characterize paleoenvironmental conditions of the deposition. Five sedimentary facies were reconstructed: (1) fan-delta to onshore environment which developed during the Lower Badenian; (2) followed by the Lower Badenian proximal slope gravity currents sediments; (3) distal slope turbidites were deposited in the Lower and Upper Badenian; (4) at the very end of the Upper Badenian and during the Sarmatian a coastal plain of normal marine to brackish environment developed; (5) sedimentation finished with the Pannonian-Pliocene shallow lacustrine to alluvial plain deposits. The provenance analysis records that the sediment of the well-cores was derived from crystalline basement granitoides and gneisses and from the Permian to Lower Cretaceous sedimentary cover and nappe units of the Western Carpathians and the Eastern Alps. Moreover, the Lower Badenian volcanism was an important source of sediments in the lower part of the sequence
The age and paleoenvironment of a late Miocene floodplain alongside Lake Pannon: Rodent and mollusk biostratigraphy coupled with authigenic 10Be/9Be dating in the northern Danube Basin of Slovakia
International audienc
Integrated biostratigraphical, sedimentological and provenance analyses with implications for lithostratigraphic ranking: the Miocene Komjatice depression of the Danube Basin
The Komjatice depression, situated on the Danube Basin’s northern margin, represents a sub-basin of the Neogene epicontinental Central Paratethys Sea and Lake Pannon. The paper provides an insight into the character of sediment provenance evolution by study of well cores (ZM-1, IV-1, MOJ-1, VR-1 wells). A modern combination of provenance, sedimentology and biostratigraphy together with the reported redefinition of Pannonian formations resulted in a new lithostratigraphy of the study area. Moreover, newly published volcanic rock age data were used for calibration of biostratigraphy. The overall age span of the sedimentary fill is occupied only by late Badenian–Sarmatian (Serravallian) to Pannonian (Tortonian–Messinian) strata: 1) the basal alluvial sediments of the newly defined Zlaté Moravce Formation; 2) late Badenian–Sarmatian (Serravalian) marine sediments of the Vráble-Pozba Fm., connected with tectonic opening of the depression; 3) Pannonian (Tortonian) coarse grained sediments of the Nemčiňany Fm. with an erosional base; 4) Pannonian (Tortonian–Messinian) predominantly fine-grained, basin floor to slope Ivanka Fm., sandy deltaic Beladice Fm. and predominantly muddy, alluvial Volkovce Fm. In the middle Miocene provenance is situated in Paleozoic sequences and Neogene volcanic rocks occurring currently in the NE. During the late Miocene, provenance is changed to the NNW (Tribeč Mts.), although the transport from the NE also remained
Multiproxy constraints on Central Paratethys Sea and Lake Pannon paleoclimate and paleoenvironment transitions during the Middle-Late Miocene (Danube Basin, Slovakia)
The Danube Basin represents a northwestern depocenter of the Middle Miocene Central Paratethys Sea, which was succeed by the Late Miocene Lake Pannon. Although this is an extensively examined area, the application of multidisciplinary studies has proven capable of drawing attention to novel information concerning the depositional environment. Thus, this study aims to reveal climatic and paleoenvironmental changes by using both archive and fresh data drawn from biomarkers, palynology, sedimentology, and geochemistry. The article also addresses the quality, quantity, and thermal maturity of organic matter in relation to hydrocarbon potential. In general, the beginning of Serravallian stage relates to a regression forced by the development of the Antarctic icesheet followed by a pronounced transgression. The results presented here show that the Central Paratethys Sea reacted to the late Badenian (Serravallian) flooding, by an event which triggered a dysoxic, but not euxinic, bottom waters. The climate remained warm and humid, with paratropical to subtropical forests on the continent. Several new depocenters developed during the Sarmatian and divided the depositional environments into a shelfbrake slope in the central part of the Danube Basin, and into deltaic and swamp environments on the basin margins. The climate changed to temperate, leading to the disappearance of subtropical taxa. A shallow lake and swamp environment developed at the beginning of the Pannonian (Tortonian), forcing a salinity decrease connected to the increase in humidity. The degree of hydrocarbon richness of the mudstones is generally fair to good, and the kerogen is of mixed marine-terrestrial origin (II and III). Nonetheless, sediments at the basin margin are clearly immature due to insufficient burial.Web of Science600art. no. 11105
Geç Mesiniyen Yaşlı Gölsel Çankırı Havzası- Değim ve Bozkır Formasyonlarinin Palinolojiye Dayalı Paleoiklimsel ve Paleoçevresel Değerlendirmesi,
40Ar/39Ar geochronology of Burdigalian paleobotanical localities in the central Paratethys (south Slovakia)
The Lipovany and Mučín paleobotanical localities contain important floral associations within the tuff horizons, which were used for determination of subtropical to tropical climatic conditions during the Early Miocene. Based on the combination of results from plagioclase and biotite 40Ar/39Ar dating, the age of the tuff deposition is around 17.3Ma. For the Lipovany locality, single-grain 40Ar/39Ar convergent ages of 17.49±0.54Ma and 17.28±0.06Ma, for plagioclase and biotite were obtained, respectively. The Mučín locality only provide an imprecise convergent age of 16.5±1.4Ma due to the small size of the analyzed plagioclase crystals. The results thus allowed to include the fossil subtropical flora of the studied localities in the late Ottnangian regional stage (upper part of the Burdigalian). Additionally, these age data indicate that deposition of the overlaying Salgótarján Formation starts much later than originally thought (during Ottnangian-Karpatian boundary)