Hungarian Geological and Geophysical Institute

Budapest, Hungary

Hungarian Geological and Geophysical Institute

Budapest, Hungary
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Barbacka M.,Hungarian Natural History Museum | Barbacka M.,Polish Academy of Sciences | Bodor E.,Hungarian Geological and Geophysical Institute | Bodor E.,Eötvös Loránd University | And 8 more authors.
Acta Palaeobotanica | Year: 2014

The Jurassic floras of Europe show considerable diversity. To examine the extent of this diversity and its possible causes we used multivariate statistical methods (cluster analysis, PCA, NMDS) to compare all significant Jurassic floras in Europe. Data were based on 770 taxa from 46 fossiliferous occurrences (25 units) from France, Germany, Greenland, Hungary, Italy, Norway, Poland, Romania, Scotland, Serbia, Sweden, Switzerland, and the United Kingdom. Statistical analyses were applied at species level and genus level, and also performed for the major plant groups. The genus cladograms show affinities between different localities based on environmental factors, while the cladograms based on species affinities indicate only taxonomical correlations. The study shows that locality age does not seem to be of paramount importance for floral composition.

Barbacka M.,Hungarian Natural History Museum | Barbacka M.,Polish Academy of Sciences | Popa M.E.,University of Bucharest | Mitka J.,Jagiellonian University | And 3 more authors.
Acta Palaeobotanica | Year: 2015

Two Early Jurassic localities, the Mecsek Mts in Hungary and Anina in Romania, are similarly significant and both floras are of autochthonous/paraautochthonous origin. In the Early Jurassic the Hungarian locality was a delta plain; the Romanian locality was an intramontane depression filled predominantly by a braided river system. The floristic composition of the two localities (52 genera, 120 species), although superficially similar (25 common genera), differs at species level (only 9 common species) as well as in the proportions of taxa in major plant groups. These differences can be explained by differences in environmental conditions resulting from palaeogeographic and topographic factors. Based on previous and recent studies, alpha diversity as well as statistically (DCA, PCA) differentiated ecogroups are compared and discussed. For common species, the GLM method was used to classify them to particular environmental response types. Their environmental requirements in both ecosystems are evaluated. Some of the shared species showed different preferences at the localities, explainable by their broad ecological tolerance.

Prondvai E.,Eötvös Loránd University | Bodor E.R.,Hungarian Geological and Geophysical Institute | Bodor E.R.,Eötvös Loránd University | Osi A.,Eötvös Loránd University
Paleobiology | Year: 2014

With a single complete mandible and 56 mandibular symphyseal fragments of various sizes, the Late Cretaceous Hungarian azhdarchid material has been considered one of the most extensive monospecific pterosaur assemblages in the world. Representing a broad size range, these elements have been thought to demonstrate a developmental series of Bakonydraco galaczi. As such, they were ideal to test whether absolute size and/or morphology reliably indicate relative ontogenetic stages in this pterosaur. Forty-five specimens were selected for multivariate morphometrics and classified into four size classes. After acquiring the morphometric data set, we thin-sectioned eight symphyses representing all size groups and classified them into relative ontogenetic stages based on qualitative microstructural inspection prior to quantitative histological analyses. Microstructural characters suggestive of developmental state were then quantified for intra- and interindividual uni- and multivariate analyses to test the correspondence among the results of qualitative and quantitative analyses. In contrast to our expectations, histological features identified the smallest specimen as an adult and not an early juvenile. The substantial size difference between this specimen and other adults, along with its distinct microanatomical and histological features, implies the presence of at least two pterosaur taxa in this symphysis assemblage. This hypothesis is further supported by multivariate morphometrics, which separate the smallest symphyses from all other specimens that form one continuous group. Although the latter group also shows considerable size variability in corresponding ontogenetic stages, this suggests developmental plasticity rather than the presence of even more taxa, and indicates that symphysis size and morphology are poor indicators of skeletal maturity in these animals. Hence, bone histology is an important independent test of the assessment of ontogenetic stage using size and morphology. © 2014 The Paleontological Society.

Xia Q.-K.,Hefei University of Technology | Liu J.,Hefei University of Technology | Liu S.-C.,Hefei University of Technology | Kovacs I.,Hungarian Geological and Geophysical Institute | And 2 more authors.
Earth and Planetary Science Letters | Year: 2013

It has been suggested that the longevity of cratons (i.e. ancient and stable cores of continents) is related in part to the low water content of their deep mantle roots; this gives them a higher viscosity than the underlying asthenosphere. Consequently, the removal of cratonic roots is expected to be closely connected to the hydration of the lithospheric mantle, but direct evidence for this speculation has been scarce. The eastern part of the North China Craton (NCC) is a clear example of a "destroyed craton". In this study the H2O content of clinopyroxene phenocrysts was measured in lithospheric mantle-derived high-magnesium basalts of the Feixian area, in the eastern part of the NCC. These lavas erupted in the early Cretaceous (~120Ma), which was the peak time of the NCC destruction. Based on these data, it was estimated that the H2O content of the lithospheric mantle source of these basalts consists of more than 1000ppm by weight. This water content is much higher than in the source of mid-ocean-ridge basalts (50-200ppm by weight) and also higher than in the Kaapvaal cratonic mantle in South Africa (~120ppm by weight); the latter is still stable after >3 billion years. This study argues that a large amount of water was indeed added to the NCC's lithospheric mantle, probably due to the multi-stage subduction of oceanic plates since the early Paleozoic. This high water content significantly reduced the viscosity contrast between the lithospheric mantle and the underlying asthenosphere, and provided a prerequisite for the removal of the cratonic root of the NCC by reducing its strength. © 2012 Elsevier B.V.

Farkas-Peto A.,Debrecen University | Horvath T.,Hungarian Academy of Sciences | Papp I.,Debrecen University | Kovacs-Palffy P.,Hungarian Geological and Geophysical Institute
Carpathian Journal of Earth and Environmental Sciences | Year: 2014

With the analysis of the middle Bronze Age (2000-1350 BC) Vatya culture findings in Pest county (Central Hungary) comprising of more than 400 polished stone tools and instrument tools this is the first archaeometric study with such scale in Hungary. In order to characterize petrographically the raw-material of the stone tools macroscopic and microscopic stone analyses were made together with mineralogical and geochemical analyses. In the course of the work a new digital database the Archaeometric Stone Tool Database was established. Based on the results, the material of the instrument stones is mainly sandstone and quartzite that were easy to collect from their source areas. Local volcanics, mostly amphibole containing andesite variations dominated among the material of the polished stone tools. Ophiolites (metamorphic basic rocks, serpentinized basic and ultrabasic rocks) were the raw-material of stone axes that indicate either more distant travels for raw-material or exchange import.

Barbacka M.,Polish Academy of Sciences | Pacyna G.,Jagiellonian University | Feldman-Olszewska A.,Polish Geological Institute National Research Institute | Ziaja J.,Polish Academy of Sciences | And 2 more authors.
Acta Geologica Polonica | Year: 2014

Plant macroremains from five boreholes in Poland were studied. Two of them (Huta OP-1 and Studzianna) from the northern margin of the Holy Cross Mountains, yielded several taxa. In the other three boreholes determinable fos-sil plants were sporadic, albeit important. Most of the taxa from the Huta OP-1 and Studzianna boreholes are typi-cal of the European Early Jurassic (Hettangian and Sinemurian). Both localities, although close to one another, show incertae sedis, Desmiophyllum harrisii phytes and conifers (a new species incertae sedis, Desmiophyllum harrisii Barbacka et Pacyna is herein proposed), which would suggest rather wet and warm conditions. This flora is typical of the European Province of the Euro-Sinian Region. In Studzianna the Siberian elements dominate, gymnosperms, mainly Czekanowskiales, which in-dicate a drier and colder environment. The palaeobotanical data correspond to the results of clay mineral studies, in particular the kaolinite/illite ratio in the source formations. The kaolinite content confirms a decrease in temperature and a reduction in rainfall in the late Early Hettangian and the latest Hettangian in the area. © 2014 Acta Geologica Polonica.

Fuleky G.,Szent Istvan University | Kalmar J.,Hungarian Geological and Geophysical Institute
Carpathian Journal of Earth and Environmental Sciences | Year: 2013

The Kömlo model area is a 250?250 m sized agricultural field in the central part of the Great Hungarian Plain. In this paper, the geological background, the hydrogeology of the area and the distribution of nutrients and trace elements of different soil levels were studied. The soil, which was formed on the clayey-silty floodplain and the sandy riverbed sediments of the old River Tisa was sampled in 25 boreholes (4 genetic levels, 108 samples) and the samples were analyzed for 23 main and trace elements. Among them, tree groups of elements were recognized: the main, rock forming elements, the trace elements of which concentration up to 1 ppm and some elements with concentrations below 1 ppm, close to the detection limit. The concentration of elements and the relation among them depend on the sediment type, on the soil level and on the presence of the groundwater table, while the areal distribution of some trace elements in the ploughed and in the root zones indicates the stream direction of the sediments during the past floods of the river Tisa.

Csaszar G.,Eötvös Loránd University | Szinger B.,Mol Nyrt. | Piros O.,Hungarian Geological and Geophysical Institute
Geologica Carpathica | Year: 2013

The Upper Triassic-Lower Cretaceous successions of the Transdanubian part of the Mecsek and Villány- Bihor Zones of the Tisza Unit have been studied from the lithological, lithostratigraphical, sedimentological, microfossil and microfacies points of view in order to correlate and interpret the significant differences between them and to draw a conclusion about their geological and paleogeographical history. After an overview of the paleogeographical reconstructions of the broader area, the succession of the Mecsek and Villány-Bihor Zones and the debated Máriaké ménd-Bár Range are introduced. Until the end of the Middle Triassic the study area acted as an entity. The first fundamental difference between the two zones can be recognized in the Late Triassic when marine carbonates were replaced by thick fluvial siliciclastics in the Mecsek Zone, while it is represented only by small, local lenses with a few and thin dolostone intercalations in the Villány Zone. The Mecsek Zone is bordered southward by one of the large listric faults to the north of which very thick siliciclastics developed in the Early to Middle Jurassic, whereas it is highly lacunose in the larger western part of the Villány-Bihor Zone. The break at the base is subaerial, higher in the succession it is shallow submarine. The sediment is silty, occasionally sandy crinoidal limestone of late Early Jurassic or even Middle Jurassic in age. The Upper Jurassic in the Mecsek Zone is composed of deep-water cherty limestone while in the Villány Zone it became a thick, shallowing pelagic limestone with reworked patch reef fragments. It is clear evidence that the Mecsek Zone had a thinned continental crust thanks to the nearby rift zone while in the Villány Zone the crust remained thick. The actualized version of the Plašienka's paleogeographical model (Plašienka 2000) is introduced.

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