MTA MTM ELTE Research Group for Paleontology
MTA MTM ELTE Research Group for Paleontology
Palotai M.,Eötvös Loránd University |
Palfy J.,Eötvös Loránd University |
Palfy J.,MTA MTM ELTE Research Group for Paleontology |
International Journal of Earth Sciences | Year: 2017
One of the key requirements for a Global Stratotype Section and Point (GSSP) is the absence of tectonic disturbance. The GSSP for the Triassic–Jurassic system boundary was recently defined at Kuhjoch, Northern Calcareous Alps, Austria. New field observations in the area of the Triassic–Jurassic boundary GSSP site demonstrate that the overturned, tight, and almost upright Karwendel syncline was formed at semibrittle deformation conditions, confirmed by axial planar foliation. Tight to isoclinal folds at various scales were related to a tectonic transport to the north. Brittle faulting occurred before and after folding as confirmed by tilt tests (the rotation of structural data by the average bedding). Foliation is ubiquitous in the incompetent units, including the Kendlbach Formation at the GSSP. A reverse fault (inferred to be formed as a normal fault before folding) crosscuts the GSSP sections, results in the partial tectonic omission of the Schattwald Beds, and thus makes it impossible to measure a complete and continuous stratigraphic section across the whole Kendlbach Formation. Based on these observations, the Kuhjoch sections do not fulfil the specific requirement for a GSSP regarding the absence of tectonic disturbances near boundary level. © 2017 The Author(s)
Budai T.,University of Pécs |
Haas J.,Geophysical and Space Science Research Group |
Voros A.,MTA MTM ELTE Research Group for Paleontology |
Molnar Z.,Eötvös Loránd University
Facies | Year: 2017
In the Middle Anisian, extensional tectonic movements led to the development of a small isolated carbonate platform in the middle part of the Balaton Highland, Transdanubian Range, Hungary. In the Late Illyrian, a condensed pelagic carbonate succession with phosphorite horizons was formed on the top of the already drowned platform. These strata contain an extraordinarily diverse ammonite fauna. This unit is overlain by radiolarian-rich carbonates, locally with radiolarite interbeds. We suggest that the drowning process and the post-drowning sediment deposition were controlled partly by regional factors, i.e., the onset of opening of the Neotethys Ocean, and partly by local factors such as the bottom topography and related current activity, which may also be connected with the opening of the ocean. The predominance of the radiolarian-rich sediments suggests eutrophic surface water, which may be explained by a monsoon-driven upwelling model. The segmented sea-floor topography together with the high-fertility surface water conditions may have provided favorable habitats for the ammonites, which may have adapted to various ecological conditions, leading to extreme diversification of this group. Since similar Middle to Late Anisian evolution was reported from many other units of the western Neotethys margin, regional factors such as the establishment of an extensional tectonic regime and related marginal basin formation, monsoon-driven upwelling, and related high surface water productivity seem to be of critical importance in controlling the depositional conditions. © 2017, Springer-Verlag GmbH Germany.
Pazonyi P.,MTA MTM ELTE Research Group for Paleontology |
Virag A.,MTA MTM ELTE Research Group for Paleontology |
Podani J.,Eötvös Loránd University |
Palfy J.,Eötvös Loránd University
Quaternary International | Year: 2017
Voles are among the most common and abundant rodents in Central Europe, represented by several species of Microtus and other genera. This group is also common in Pleistocene fossil assemblages. However, the taxonomy of fossil finds, largely based on lower first molars, is fraught with problems and opinions of various authors often diverge, hampering phylogenetic inferences and reconstruction of lineages which led to the extant species. To help solve taxonomic incongruence, we carried out morphometric analyses on the abundant late Early Pleistocene finds from the exceptionally rich site of Somssich Hill 2 (Villány Mts., southern Hungary), complemented with less numerous but also well-dated and nearly coeval material from nearby sites Villány 6 and 8, as well as Kövesvárad from northern Hungary. Landmark analysis was performed in the present paper, and in addition, cluster and discriminant analyses were applied on the conventional linear data derived from the landmark coordinates. First lower molars of well-established recent taxa from zoological museum collections were also included in the analyses, both to assess their degree in intraspecific morphological variability to inform delineation of the extinct taxa, and to compare morphologies of fossil and recent taxa to establish phylogenetic relationships. Morphometric analyses revealed that the material from Somssich Hill 2 represents a single species, Microtus nivaloides, whereas specimens from the somewhat younger site Villány 8 belong to M. nivalinus. Paleoecology of the accompanying taxa in the fossil assemblages suggests differences in their habitat: M. nivalinus preferred more open vegetation, whereas M. nivaloides was restricted to forested areas. Geometric morphometric analyses together with modern taxa defined a morphospace where the consensus shape of M. nivaloides is centrally located, supporting the hypothesis that it represents the ancestor of modern Microtus (Microtus) species and forms part of a lineage which led to the M. arvalis-agrestis group. On the other hand, morphological similarities suggest a split lineage and phylogenetic relations of late Early Pleistocene M. nivalinus and the recent M. oeconomus. The emergence of 'true' Microtus species stems from the radiation initiated around 1.0-0.9 Ma, an important phase in vole evolution revealed by the rich finds from Somssich Hill 2 and other sites. © 2017 Elsevier Ltd and INQUA.
Finsinger W.,Montpellier University |
Kelly R.,University of Illinois at Urbana - Champaign |
Fevre J.,Montpellier University |
Magyari E.K.,MTA MTM ELTE Research Group for Paleontology
Holocene | Year: 2014
Macroscopic charcoal records can be used to infer spatially explicit reconstructions of past fire history. However, a current deficiency in the charcoal-analysis toolbox has been the lack of a method to consider sampling variability and charcoal-particle area distributions for peak detection with charcoal-area records. We present a screening procedure specific for datasets comprising charcoal numbers and areas to screen the charcoal-area estimates with respect to the count sums. The rationale for screening charcoal-area peaks stems from the observation that although charcoal-area records can be more suitable in a statistical sense for peak detection (e.g. as established by the signal-to-noise index), charcoal-area peaks can be questionable if they are determined by just one or a few larger charcoal particles. Our method begins with a charcoal-area time series analysed by existing methods to identify peaks representing fire episodes. To screen these peaks, the method uses bootstrap resampling of charcoal-particle areas observed in a user-defined subsection of the record around each peak to obtain the range of likely charcoal areas for different counts. Peaks with total area within the likely range of bootstrapped samples (e.g. p > 0.05) are flagged as potentially unreliable, whereas samples with total area significantly greater than expected by chance are deemed robust indicators of past fire events. In an example application of the method to a charcoal record from Lake Brazi, Romania, several peaks failed to pass the screening suggesting that, as for count-based records, unscreened charcoal-area records may include spurious fire episodes and thus potentially underestimate past fire-return intervals. © The Author(s) 2014.
Kocsis L.,University of Lausanne |
Ozsvart P.,MTA MTM ELTE Research Group for Paleontology |
Becker D.,Jurassica Museum |
Ziegler R.,Staatliches Museum fur Naturkunde Stuttgart |
And 2 more authors.
Geology | Year: 2014
Terrestrial climatic data reflect variable and often conflicting responses to the global cooling event at the Eocene-Oligocene transition (ca. 34 Ma). Stable isotopic compositions of the tooth enamel of large, water-dependent, herbivorous terrestrial mammals are investigated here to better understand the European continental climate during the late Eocene- early Oligocene. High δ18OPO4 and δ13C values reflect a semiarid climate and ecosystem in the late Eocene. In the west-southwest region of Europe, these conditions prevailed until at least 33 Ma, after which it became more humid. A similar change was recorded north of the Alpine thrust, but it occurred 2 m.y. earlier. The north and west-southwest regions show a significant offset in δ18OPO4 composition between 35 and 31 Ma, indicating the influence of different air trajectories with different moisture sources (Atlantic versus Tethys). This also marks the presence of an orographic height in central Europe from the latest Eocene. After 31 Ma, a large drop in δ18OPO4 is registered, explained by altitude-induced fractionation on meteoric water isotopic composition. The related paleoaltitude change is estimated to be 1200 m, and the uplift could have taken place along the Alpine-Dinaridic orogenic system. © 2014 Geological Society of America.
Magyari E.K.,MTA MTM ELTE Research Group for Paleontology |
Kunes P.,Charles University |
Jakab G.,Szent Istvan University |
Sumegi P.,University of Szeged |
And 4 more authors.
Quaternary Science Reviews | Year: 2014
To characterize Late Pleniglacial (LPG: 26.5-15kacalBP) and particularly Last Glacial Maximum (LGM: 21±2kacalBP) vegetation and climate, fossil pollen assemblages are often compared with modern pollen assemblages. Given the non-analogue climate of the LPG, a key question is how glacial pollen assemblages and thereby vegetation compare with modern vegetation. In this paper we present three LPG pollen records from the Carpathian Basin and the adjoining Carpathian Mountains to address this question and provide a concise compositional characterization of the LPG vegetation. Fossil pollen assemblages were compared with surface pollen spectra from the Altai-Sayan Mountains in southern Siberia. This area shows many similarities with the LPG vegetation of eastern-central Europe, and has long been considered as its best modern analogue. Ordination and analogue matching were used to characterize vegetation composition and find the best analogues. Our results show that few LPG pollen assemblages have statistically significant analogues in southern Siberia. When analogue pairings occur they suggest the predominance of wet and mesic grasslands and dry steppe in the studied region. Wooded vegetation types (continental and suboceanic hemiboreal forest, continental taiga) appear as significant analogues only in a few cases during the LGM and more frequently after 16kacalBP. These results suggest that the LPG landscape of the Carpathian Basin was dominated by dry steppe that occurred outside the river floodplains, while wet and mesic grasslands occurred in the floodplains and on other sites influenced by ground water. Woody vegetation mainly occurred in river valleys, on wet north-facing hillsides, and scattered trees were likely also present on the loess plateaus. The dominant woody species were Larix, Pinus sylvestris, Pinus mugo, Pinus cembra, Picea abies, Betula pendula/. pubescens, Betula nana, Juniperus, Hippophaë rhamnoides, Populus, Salix and Alnus. The pollen records suggest uninterrupted presence of mesophilous temperate trees (Quercus, Ulmus, Corylus, Fagus and Fraxinus excelsior) in the Eastern Carpathian Mountains throughout the LPG. We demonstrate that the LPG vegetation in this area was characterized by increasing grass cover and high frequency of wildfires. We conclude that pollen spectra over represent trees in the forest-steppe landscape of the LPG, furthermore pollen-based quantitative climate reconstructions for the LPG are challenging in this area due to the scarcity of modern analogues. © 2014 Elsevier Ltd.
Sumegi P.,University of Szeged |
Sumegi P.,Hungarian Academy of Sciences |
Magyari E.,MTA MTM ELTE Research Group for Paleontology |
Daniel P.,Biogal Pharmavit Rt |
And 2 more authors.
Quaternary International | Year: 2013
According to the findings of a complex sedimentological, geochemical, malacological and pollen study implemented on a core sequence of an alkaline lake (Fehér Lake), interstadials in the SE Great Hungarian Plain were characterized by increased boreal woodland cover during Marine Isotope Stage 2 (MIS 2: 29,700-14,500 cal BP). These interstadials were dated to 26,420-27,970, 23,185-24,880, and 18,810-20,770 cal BP, and correlate well with the Dansgaard-Oeschger (DO) interstadials 2 and 3 and the post LGM warm interval seen in the Greenland ice core oxygen isotope records. Intervening cold phases, on the other hand, were found between 24,880-26,420 and 20,770-23,185 cal BP, correlating with Heinrich event 2 and the LGM. These data overall confirm that millennial scale climate variability during Marine Isotope Stage 2 had profound effect on the terrestrial ecosystems in the continental interior of SE Europe, leading to periodic boreal woodland expansions and contractions and wildfires. © 2012 Elsevier Ltd and INQUA.
Price G.D.,University of Plymouth |
Fozy I.,Hungarian Natural History Museum |
Palfy J.,Eötvös Loránd University |
Palfy J.,MTA MTM ELTE Research Group for Paleontology
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2016
We present new carbon and oxygen isotope curves from sections in the Bakony Mts. (Hungary), constrained by biostratigraphy and magnetostratigraphy in order to evaluate whether carbon isotopes can provide a tool to help establish and correlate the last system boundary remaining undefined in the Phanerozoic as well provide data to better understand the carbon cycle history and environmental drivers during the Jurassic-Cretaceous interval. We observe a gentle decrease in carbon isotope values through the Late Jurassic. A pronounced shift to more positive carbon isotope values does not occur until the Valanginian, corresponding to the Weissert event. In order to place the newly obtained stable isotope data into a global context, we compiled 31 published and stratigraphically constrained carbon isotope records from the Pacific, Tethyan, Atlantic, and Boreal realms, to produce a new global δ13C stack for the Late Oxfordian through Early Hauterivian interval. Our new data from Hungary is consistent with the global δ13C stack. The stack reveals a steady but slow decrease in carbon isotope values until the Early Valanginian. In comparison, the Late Jurassic-Early Cretaceous δ13C curve in GTS 2012 shows no slope and little variation. Aside from the well-defined Valanginian positive excursion, chemostratigraphic correlation durSchning the Jurassic-Cretaceous boundary interval is difficult, due to relatively stable δ13C values, compounded by a slope which is too slight. There is no clear isotopic marker event for the system boundary. The long-term gradual change towards more negative carbon isotope values through the Jurassic-Cretaceous transition has previously been explained by increasingly oligotrophic condition and lessened primary production. However, this contradicts the reported increase in 87Sr/86Sr ratios suggesting intensification of weathering (and a decreasing contribution of non-radiogenic hydrothermal Sr) and presumably a concomitant rise in nutrient input into the oceans. The concomitant rise of modern phytoplankton groups (dinoflagellates and coccolithophores) would have also led to increased primary productivity, making the negative carbon isotope trend even more notable. We suggest that gradual oceanographic changes, more effective connections and mixing between the Tethys, Atlantic and Pacific Oceans, would have promoted a shift towards enhanced burial of isotopically heavy carbonate carbon and effective recycling of isotopically light organic matter. These processes account for the observed long-term trend, interrupted only by the Weissert event in the Valanginian. © 2016.
Feurdean A.,Senckenberg Institute |
Feurdean A.,Romanian Academy of Sciences |
Spessa A.,Senckenberg Institute |
Spessa A.,Max Planck Institute for Chemistry |
And 6 more authors.
Quaternary Science Reviews | Year: 2012
Fire is recognized as a critical process with significant impacts on biota and the atmosphere. In this study, 11 micro- and macrocharcoal sedimentary records extracted from peat bogs and lakes at different elevations in the Carpathian region (in Hungary and Romania) were used to explore the patterns and the potential underlying mechanisms in biomass burning in this region during the last 15,000 years. Results from micro-charcoal and macro-charcoal data show similar trends in biomass burning and suggest that the major signal of both charcoal size-fragments relates mainly to local fires. Fire activity was low during the lateglacial, attained maximum values in the early Holocene (11,700-8000 cal. yr BP), become lower than present during the mid-late Holocene (8000-1000 cal yr BP), and increased again over the last 1000 years. The reconstructed spatial trends in biomass burning display different degrees of heterogeneity through time. Generally, there was more spatial similarity in fire activity across the study region during the lateglacial and early Holocene (15,000-8000 cal yr BP), followed by increased spatial heterogeneity from ca 8000 cal yr BP onwards. Biomass burning appears to have been primarily modulated by climate during both the lateglacial and Holocene, through its effect on vegetation productivity and therefore fuel availability (lateglacial), and fuel structure, moisture and flammability (the Holocene). Onsite human activities are likely to have provided an extra ignition source already in the early Holocene. However, evidence suggest that anthropogenic activities have markedly altered the natural trends in biomass burning from about 5500 yr BP (lowlands) and over the last 2000-1000 years (in the mountain environments), by either removing the biomass (in the lowlands) or igniting fire where it seldom occurs naturally (i.e., in the mountain environments). On the other hand, burning activity also appears coincident with significant changes in tree species compositions, indicating that fire has likely acted as a driving factor in forest dynamics. Results also suggest that peat deposits provide a more localized fire record than lakes, and that trends and patterns of change can be different even for sites situated close to each other. © 2012 Elsevier Ltd.
A taxonomic and nomenclatural revision of the historical brachiopod collection from the lower jurassic of yakacik (Ankara, Turkey), Housed in the geological and geophysical institute of Hungary [A magyar földtani és geofizikai intézetben őrzött törökországi (yakacik, Ankara) alsó-jura brachiopoda gyűjtemény revíziója]
Attila V.,MTA MTM ELTE Research Group for Paleontology
Foldtani Kozlony | Year: 2013
In this paper the Early Jurassic brachiopods from Yakacik (Turkey), housed at the Geological and Geophysical Institute of Hungary, are examined in detail in the framework of a taxonomic and nomenclatural revision of the 197 specimens collected by R. MILLEKER in 1911-1912, and shortly described by VADÁSZ (1913a, b, 1918). This revision resulted in the identification of 27 brachiopod taxa. They represent 16 genera and 23 nominal species; these are systematically described and documented by photographs and partly by serial sections. The new brachiopod taxa introduced and illustrated by VADÁSZ (1913a, b): Rhynchonellina anatolica and Waldheimia anatolica are re-evaluated and their taxonomic positions are updated as Suessia ? anatolica (VADÁSZ, 1913) and Aulacothyris anatolica (VADÁSZ, 1913), respectively. The Early Jurassic (Pliensbachian) brachiopod fauna of Yakacik shows a transitional character between two major faunal provinces: besides 4 endemic and 4 cosmopolitan species, 6 species have NW European, and 9 species have Mediterranean faunal affinity. © 2014 Hungarian Geological Society. All rights reserved.