Kovacs J.,University of Pécs |
Moravcova M.,State Geological Institute of Dionyz Stur |
Ujvari G.,Geodetic and Geophysical Institute of the RCAES HAS |
Pinter A.G.,University of Pécs
Quaternary International | Year: 2012
Stable carbon and oxygen isotope values (δ 13C, δ 18O) of structural carbonate were determined in the bioapatite component of fossil teeth from the Czech Republic, Slovakia and Hungary. Oxygen isotope compositions of enamel and dentin samples provide new quantitative records of the Late Pleistocene climate in East Central Europe (ECE). These δ 18O data were combined with records of oxygen isotope values of recent and paleogroundwaters to study the spatial patterns and temporal variations in the oxygen isotope composition of precipitation and the thermal climate over ECE. The new isotopic data suggest that surface air temperatures in the study region between 33 and 12 ka were 2-9 °C colder than present. Specimens of woolly mammoth, rhino and horse from the Late Pleistocene were primarily C 3 grazers. © 2012 Elsevier Ltd and INQUA.
Vojtko R.,Comenius University |
Petro L.,State Geological Institute of Dionyz Stur |
Benova A.,Comenius University |
Bona J.,State Geological Institute of Dionyz Stur |
Hok J.,Comenius University
Geomorphology | Year: 2012
This study investigates the influence of neotectonic activity on river and basin patterns in a mountainous area located in the northeastern part of the Carpathian Belt (the Laborecká vrchovina and Bukovské vrchy Mts. in eastern Slovakia). This area evolved within the accretionary wedge of the Carpathians during the Neogene, and it was alsowas affected by Middle to Late Miocene thrusting of the External Carpathians. Morphometric analysis, longitudinal and transverse river valley profiles, analysis of basin and valley symmetries, and investigation of alluvial terraces were carried out on the northern Laborec River and its tributaries. This was done to detect a possible relationship between their river courses and any ongoing neotectonic activity, which is otherwise difficult to detect by methods of structural geology because of the poorly exposed area. The general topography of the basin is characterized by a stepwise inclination to the SW as a result of differential uplift and subsidence. The reorganization of the river network in the Laborec drainage basin was influenced by tectonic activity along the NE-SW up to N-S fault structures during the neotectonic phase (Pliocene-Quaternary). The movement along these fault structures is predominantly normal to transtensive. The obtained data assumes that the region is under approximately NE-SW oriented SH compression and NW-SE trending Sh tension. The Laborec drainage basin is characterized by a very high degree of asymmetry that sharply increases from the upper to the lower courses of the river. The right-bank tributaries of the Laborec River are <12km in length; however, the left-bank tributaries such as Vydraňka, Ol'šava, Výrava, Udava, and Cirocha Streams are up to 50km long with a high potential of headward erosion and capturing. The valley asymmetry is also very variable in the upper and lower portions of the basin. Based on these presented results, the ancient river thalweg was located along the axis of the Hostovice-Habura depression, and it was captured by the Ol'šava, Výrava, and Udava Streams. The asymmetric pattern of the drainage basin is the result of active tectonics, the continual subsidence of the Transcarpathian Basin, and by the uplift of the Laborecká vrchovina and Bukovské vrchy Mts. These events caused rejuvenation of the headward erosion of streams in the southern part. Favorable lithology was also essential in the process of river capture. © 2011 Elsevier B.V.
Vozarova A.,Comenius University |
Konecny P.,State Geological Institute of Dionyz Stur |
Sarinova K.,Comenius University |
Vozar J.,Slovak Academy of Sciences
International Journal of Earth Sciences | Year: 2014
The Southern Gemericum basement in the Inner Western Carpathians experienced a polyphase regional deformation. Differences in the pre-Alpine and Alpine events have been constantly discussed. To address this, monazites from metapelites and acid metavolcanic rocks were dated using the Th-U-Pb electron microprobe method. Three monazite generations, such as Precambrian, Early Paleozoic, and Alpine, have been recognized in the greenschist facies pelites and acid metavolcanic rocks of the Southern Gemericum basement. Both inherited magmatic monazite grains in metavolcanites and rare relics of detrital monazites within the polyphase monazite grains in metapelites yielded the Precambrian age in the time span of 550-660 Ma. They prove the provenance and derivation from deeper crustal Cadomian fragments. High-Y magmatic monazites of Early Paleozoic age (444 ± 13 and 477 ± 7 Ma) have been recorded in the acid metavolcanites and their metavolcaniclastics. These ages roughly fit within the previously published magmatic zircon age determinations (at 494 ± 1.7 and 464 ± 1.7 Ma) that clearly indicate two-phase volcanic activity in the Early Paleozoic Southern Gemericum basin. The Early Paleozoic magmatic monazites were partly overprinted by the low-Y Alpine monazites (133 ± 5 and 184 ± 16 Ma) at their rims. In Al-rich metapelites, the newly formed low-Y monazites of Alpine age commonly occur, reflecting the polystage compression geodynamic evolution with three distinct peaks at 100 ± 8, 133 ± 5, and 190 ± 16 Ma, respectively. No data as the evidence of the pre-Alpine metamorphic events were observed in metapelites. Only some monazites yield the age indications for the Permian extensional thermal re-heating (260-290 Ma). The monazite age data from the Southern Gemericum basement indicate the strong overprinting due to the polyphase Alpine deformation at least in the greenschist facies conditions. © 2014 Springer-Verlag Berlin Heidelberg.
Malik P.,State Geological Institute of Dionyz Stur |
Svasta J.,State Geological Institute of Dionyz Stur
Acta Carsologica | Year: 2010
Using archival hard copy records on 22,922 wells and hydrogeological boreholes, maintained since 1950's on the territory of Slovak Republic, a spatial database was developed. If possible, eachborehole was linked to a certain aquifer or aquifer lithological type, according to its screened interval. Wells with ambiguous position of open casing were excluded from further processing to obtain distinct relation of pumping rate to lithology. Using stored records of hydraulic tests, each pumping rate was processed to obtain uniformly calculated "standard" specific capacity. These values were subsequently used to re-interpret hydraulic parameters. Based on standardized specific capacity data, estimates of transmissivity (T; in m 2s -1) and hydraulic conductivity (K; in ms -1) for each well were calculated and linked to corresponding aquifer type. From these, hydraulic properties of limestones (238 boreholes), dolomites (463 boreholes) and granitoid rocks (96 boreholes) are compared. As anticipated, geometrical mean of transmissivity was low for granitoids (6.51 10 -5 m 2s -1) and in one order of magnitude higher for limestones (6.16 10 -4 m 2s -1), due to its enhancement by karstification. The highest observed value of mean transmissivity, two times higher than that found for limestones, was obtained for dolomitic aquifers (1.04 10 -3 m 2s -1). Dolomitic aquifers also show the highest median values of hydraulic conductivity (3.21 10 -6 m s -1), in one order of magnitude higher than granitoids (2.10 10 -5 m s -1) and three times higher than limestones (9.45 10 -6 m s -1). In comparison with limestones, dolomites seem to be slightly more homogeneous in aquifer properties; also several lithological types there show similarities in both T and K. Some limestone lithofacies (Steinalm and Raming), seem to have lower transmissivity and hydraulic conductivity comparing to other limestones types (Dachstein, Gutenstein, Wetterstein). The data on hydraulic properties of all these hard rocks show lognormal statistical distribution and high heterogeneity.
Oxygen isotopes in different recession subregimes of karst springs in the brezovské karpaty Mts. (Slovakia) [Izotopi kisika v različnih podrežimih recesije kraškihizvirov v brezovskih karpatih(Slovaška)]
Malik P.,State Geological Institute of Dionyz Stur |
Michalko J.,State Geological Institute of Dionyz Stur
Acta Carsologica | Year: 2010
Karst spring hydrograph separation method based on quick iterative solution of several simple exponential and linear equations, was developed for linking small datasets of samples to various hydrologic situations. The method is based on a presumption, that a spring's discharge depends on the level of aquifer saturation by groundwater, and that the same discharge reflects the same groundwater saturation (piezometric level) in the aquifer. Every spring can be described by unique sets of constant starting discharges, Q0 values, recession coefficients α (laminar flow components in exponential equations), and β (turbulent flow components in linear equations). Each subregime can be detected by recession curve analyses of the complete spring's discharge time series. In this hydrograph separation, every measured discharge value, Qt, is then determined by a representative time, t; i.e., theoretical elapsed time t from the total maximum discharge value Qmax. The aim of the iteration process is to obtain this representative time t for each discharge. The individual flow components are calculated using the same t value. These variances in subregime discharges in a certain moment can be linked to the components analysed in the same moment, in order to obtain the end members of the theoretical mixture. This technique was developed and applied on the discharge time series of the four karstic springs in the Brezovské Karpaty Mts. (Slovakia), built mainly by karstified Middle and Upper Triassic dolomites and limestones. Groundwater of individual springs were characterised by δ18O (SMOW) and groundwater temperature values and end members of two laminar and one turbulent subregimes were calculated. Results were based on sparsely populated datasets and manual discharge records, but represent a perspective method for future development and interpretations on limited dataset results.
Aubrecht R.,Comenius University |
Aubrecht R.,Slovak Academy of Sciences |
Lanczos T.,Comenius University |
Gregor M.,Comenius University |
And 5 more authors.
Geomorphology | Year: 2011
Venezuelan table mountains (tepuis) host the largest arenite caves in the world. The most frequently used explanation of their origin so far was the "arenization" theory, involving dissolution of quartz cement around the sand grains and subsequent removing of the released grains by water. New research in the two largest arenite cave systems - Churi-Tepui System in Chimanta Massif and Ojos de Cristal System in Roraima Tepui showed that quartz dissolution plays only a minor role in their speleogenesis. Arenites forming the tepuis are not only quartzites but they display a wide range of lithification and breakdown, including also loose sands and sandstones. Speleogenetic processes are mostly concentrated on the beds of unlithified sands which escaped from diagenesis by being sealed by the surrounding perfectly lithified quartzites. Only the so-called "finger-flow" pillars testify to confined diagenetic fluids which flowed in narrow channels, leaving the surrounding arenite uncemented. Another factor which influenced the cave-forming processes by about 30% was lateritization. It affects beds formed of arkosic sandstones and greywackes which show strong dissolution of micas, feldspars and clay minerals, turning then to laterite ("Barro Rojo"). The main prerequisite to rank caves among karst phenomena is dissolution. As the dissolution of silicate minerals other than quartz appears to play not only a volumetrically important role but even a trigger role, these arenitic caves may be ranked as karst. © 2011 Elsevier B.V.
Fojtikova L.,Slovak Academy of Sciences |
Fojtikova L.,Comenius University |
Vavryauk V.,Academy of Sciences of the Czech Republic |
Cipciar A.,Slovak Academy of Sciences |
And 2 more authors.
Tectonophysics | Year: 2010
We have analyzed 44 micro-earthquakes with magnitudes between 1.2 and 3.4, which occurred in the Dobrá Voda area, Slovakia, in the period 2001-2009. The epicentres of the micro-earthquakes form a cluster elongated in the ENE-WSW direction. This direction coincides with the orientation of the main fault systems in the area: Dobrá Voda and Brezová faults. The depths of the hypocentres vary from 1km to 14km. Three different methods were used to calculate the focal mechanisms: (a) a method using the polarities of Pg and Pn waves, (b) the P-wave amplitude inversion of moment tensors, and (c) the waveform inversion of moment tensors. The majority of the analyzed micro-earthquakes have a left-lateral strike-slip focal mechanism with weak normal or reverse components. The full moment tensors comprise significant non-double-couple (non-DC) components. The non-DC components are partly numerical errors of the inversion but might be also of a physical origin. The most accurate values of the non-DC components are obtained from the P-wave amplitude inversion. For this inversion, the isotropic component (ISO) and the compensated linear vector dipole component (CLVD) are mostly positive and well correlated. This might indicate tensile faulting. Adopting the model of tensile faulting, we estimated the mean ratio of P to S wave velocities in the focal area from the values of ISO and CLVD, vP/vS=1.5-1.6. The three different datasets of the focal mechanisms have been inverted for the present-day tectonic stress in the Dobrá Voda area. The slip shear stress component criterion was applied in the stress inversion. The results of the three inversions are well-consistent and point to a high reliability and good accuracy of the inverted stress. The orientations of the principal stresses are (azimuth/plunge): σ1=210-220°/5-25°, σ2=70-105°/55-75°, and σ3=305-315°/15-25°, and the shape ratio is R=0.45-0.60. The azimuth is measured clockwise from the north and the plunge downwards from the horizontal plane. The retrieved maximum compression lies along the belt of the Malé Karpaty Mts. The local tectonic stress reflects complex tectonic conditions in the area. The presence of tensile faulting might point to an extensional stress regime in the area. © 2010 Elsevier B.V.
Radvanec M.,State Geological Institute of Dionyz Stur |
Tucek T.,State Geological Institute of Dionyz Stur |
Derco J.,State Geological Institute of Dionyz Stur |
Cechovska K.,State Geological Institute of Dionyz Stur |
Nemeth Z.,State Geological Institute of Dionyz Stur
Journal of Hazardous Materials | Year: 2013
Asbestos cement materials, mainly the eternit roof ceiling, being widely applied in the past, represent a serious environmental load. The solar radiation, rain and frost cause the deliberation of cement from the eternit roofing and consequently the wind contaminates the surrounding area by the asbestos (chrysotile) fibers. In combination with other carcinogens (e.g. smoking), or at reduced immunity of a man, they may cause serious respiratory diseases and lung cancer.The article presents the procedure and experimental results of artificial carbonatization, applied in the asbestos cement (eternit). The wet crushed and pulverized asbestos cement was thermally modified at 650°C and then the chrysotile fibers easily and completely reacted with the mixture of CO2 and water, producing new Mg-rich carbonates - hydromagnesite and magnesite: Applying this methodology, the asbestos-bearing waste can be stabilized and environmentally friendly permanently deposited. Finding a way of neutralizing of extreme pH values (around 12) at large eternit dumps represents also an asset of presented research.Simultaneously, the artificial carbonatization of chrysotile asbestos, applying CO2, offers an alternative way for permanent liquidation of a part of industrial CO2 emissions, contributing to multiple benefit of this methodology. © 2013 Elsevier B.V.
Bednarik M.,Comenius University |
Paudits P.,State Geological Institute of Dionyz Stur
Environmental Earth Sciences | Year: 2010
The article draws a comparison between different ways of landslide geometry interpretation in the scope of the statistical landslide hazard and risk assessment processing. The landslides are included as a major input variable, which are compared with all of the input parametric factors. Based on the above comparison the input data are classified and the final map of landslide susceptibility is constructed. Methodology of multivariate conditional analysis has been used for the construction of final maps. Unique condition units was developed by combination of geological map (lithological units) and slope angle map. Lithological units were derived from geological map and subsequently reclassified into 22 classes. Slope angle map was calculated from digital elevation model (contour map at a scale 1:10,000) and reclassified into nine classes. As a case study, a wide area of Horná Súča (western Slovakia) strongly affected by landsliding (predominantly made of Flysch) has been chosen. Spatial data in the form of parametric maps, as well as final statistical data set were processed in GIS GRASS environment. Four different approaches are used for landslides interpretation: (1) area of landslide body including accumulation zone, (2) area of depletion zone, (3) lines of elongated main scarps, (4) lines of main scarp upper edge. For each approach, a zoning map of landslide susceptibility was compiled and these were compared with each other. Depending on the interpretation approach, the final susceptibility zones are markedly different (in tens of percent). © 2009 Springer-Verlag.
Rakovsky J.,Laboratory Interdisciplinaire Carnot de Bourgogne |
Rakovsky J.,Comenius University |
Musset O.,Laboratory Interdisciplinaire Carnot de Bourgogne |
Buoncristiani J.,CNRS Biogeosciences Laboratory |
And 5 more authors.
Spectrochimica Acta - Part B Atomic Spectroscopy | Year: 2012
This paper illustrates the potentialities of a home-made portable LIBS (laser-induced breakdown spectroscopy) instrument in Earth sciences, more particularly in geochemically recognizing (i) tephra layers in lacustrine sediments and (ii) fossilization processes in ammonites. Abundances for selected lines of Al, Ca, Fe, Ti, Ba and Na were determined in lacustrine chalk sediments of the Jura, where the Laacher See Tephra (LST) layer is recorded. A statistical treatment of elemental maps produced from the section of a sedimentary column containing the LST event allows instrumental conditions to be optimized. Accumulating spectra from close shot positions gives better results than multiplying shots at the same location. A depth profile method was applied to study ammonite fossilization (pyritization, phosphatization) processes. Depth variations of Fe, Ca, Al intensities, and Fe/Ca and Al/Ca ratios provide indications about pyritization, but phosphatization processes cannot be determined with our device. © 2012 Elsevier B.V.