On the geochemistry of strontium in tertiary igneous rocks of the Tokaj Mountains     

Dr. A. Kovách  Dr. K. Balogh 《Mineralogy and Petrology》1969,13(1):15-33

Summary The distribution of strontium in 26 igneous rocks from the Tokaj Mountains, ranging from basalt to rhyolite has been determined by using stable isotope dilution techniques. The comparison with main component analytical data allows a classification of the different rock types (basalts, andesites, dacites, rhyolites) into only two distinctly separate genetic groups, which can be described schematically by independent liquid-solid fractionation processes. It is shown that alkaline metasomatism can produce Sr/Ca relationships similar to those developed in a liquid-solid fractionation process. Contamination by partial melting of crustal rocks, as well as magma contamination by transvaporizational mechanisms, results in similar changes in the Sr/Ca ratio, which therefore can be misleading in defining various stages of magma development.

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Über die Geochemie des Strontiums in tertiären Erstarrungsgesteinen des Tokaj-Gebirges

Zusammenfassung Die Strontiumverteilung in 26 Erstarrungsgesteinen des Tokaj-Gebirges wurde mit der Isotopenverdünnungsmethode bestimmt. Der Vergleich mit den chemischen Hauptkomponenten läßt die Einteilung der verschiedenen Gesteinstypen (Basalte, Andesite, Dazite, Rhyolite) in nur zwei, genetisch voneinander deutlich verschiedenen Reihen zu; diese können schematisch als voneinander unabhängige Fraktionierungsprozesse zwischen liquider und fester Phase beschrieben werden. Es wird gezeigt, daß Alkalimetasomatose Sr/Ca-Beziehungen erzeugen kann, die denen durch Liquidus/Solidus-Fraktionierung hervorgerufenen ähnlich sind. Kontamination durch partielles Aufschmelzen von Krustengesteinen und Magmenkontamination durch Transvaporisationsprosesse bewirken ähnliche Änderungen im Sr/Ca-Verhältnis; dieses kann daher bei der Definition verschiedener Stadien der Magmenentwicklung zu Fehldeutungen führen.

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With 3 Figures  相似文献   

Basic consideration on storage of compressed natural gas in rock chambers   总被引：1，自引：0，他引：1  

K. Kovári 《Rock Mechanics and Rock Engineering》1993,26(1):1-27

Summary Compressed gas energy storage (CGES) works with gas in the gas phase and not in the liquid phase, thus avoiding the necessity of temperatures below 0° C. The paper discusses fundamental aspects of the two possible concepts of gas storage in rock: in lined and unlined chambers. Emphasis is placed on the rock engineering problems associated with the design of such schemes. It becomes clear, however, that the thermodynamic background, the operational aspects and safety concerns strongly interact with rock mechanics considerations.  相似文献   

Blei-Isotopen-Verhältnisse im Raum der alpin-mediterranen Metallogenese     

Dr. Adam Kovách 《International Journal of Earth Sciences》1968,57(2):372-385

Zusammenfassung Die statistische Bearbeitung der Isotopenverhältnisse von Bleierzen des alpinmediterranen Raumes ergab den von W. E.Petrascheck behaupteten engen genetischen Zusammenhang zwischen den einzelnen metallogenetischen Provinzen des genannten Gebietes. Gleichzeitig weisen die Resultate auf einen engen Zusammenhang der Vererzungen mit der magmatisch-sedimentären Vorgeschichte des untersuchten Gebietes hin. Die alt- und jungpaläozoischen sowie die mesozoischen Vererzungen scheinen eine verhältnismäßig einfache Vorgeschichte zu besitzen; im Känozoikum tritt dagegen eine aus mehr heterogenen Quellen stammende Stoffzufuhr ein.

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The statistical evaluation of the isotopic composition of ore leads from the Alpine-Mediterranean system seems to support the assumption of W. E.Petrascheck about the presence of a strong genetical connection between the individual metallogenetical provinces in this area. At the same time, the results indicate a strong connection between ore mineralization and the magmatical-sedimentological history of the studied area. The source system of the Early and Late Palaeozoic, as well as of the Mesozoic ores seem to possess a rather simple genetical history; in the Tertiary a supply of ore material from a more heterogeneous source is implied.

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Résumé L'élaboration statistique des donnés de composition isotopique des mineraus de plomb provenant du système alpin-mediterranéen souligne la liaison génétique étroite entre les unités métallogéniques postulée par W. E.Petrascheck. Les résultats indiquent en même temps des rapports immédiats entre la métallogénie et l'évolution magmatique-sédimentaire de l'endroit. Quant aux minéralisations paléozoiques inférieures et supérieures ainsi que mésozoiques il semble s'agir de phénomènes plus globaux, tandis que les minéraus du Tertiaire relèvent des sources plus complexes.

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The Western Carpathians—interaction of Hercynian and Alpine processes     

Miroslav Bielik  Jn &#x;efara  Michal Kov   Vladimír Bezk  Du&#x;an Pla&#x;ienka 《Tectonophysics》2004,393(1-4):63

The complicated structural and rheologic properties of Western Carpathian lithosphere reflect the complex geodynamic history of the Carpathian orogen. Based on critical analysis of earlier models, new interpolation of existing geophysical data and results of integrated modelling, a new map of the lithosphere thickness for the Carpathian–Pannonian region has been constructed. The map allows for the distinction of a frontal orogen collision zone in the NE (from increased lithosphere thickness) as well as a zone of oblique collision with the Bohemian Massif in the West, where lithosphere is not significantly thickened. The MOHO discontinuity beneath the Western Carpathian hinterland (Danube and East Slovak Basins), as defined by deep reflection seismic profiling, is relatively shallow. This probably reflects recent crustal extension related to oblique collision between the European plate and the ALCAPA block and an increase of the asthenospheric updoming from the Middle Miocene onward.Crustal thickness reflects the combined effects of deep-seated orogenic processes and mantle thermal evolution beneath the Pannonian Basin system. In this study, we focus particularly the structures of: (1) the Late Alpine collision and Neogene back arc basin development, including deep-seated contacts between colliding plates, a zone of slab detachment, the compressional accretionary wedge of the Outer Western Carpathian Flysch Belt, and extensional structures produced by subduction rollback and asthenosphere upwelling; (2) Early Alpine structures related to Cretaceous thrust-stacking, including subhorizontal reflection packages (interpreted as multi-generational extensional structures), the underplated intra-Penninic (Oravic) continental ribbon, and ophiolite traces of the Meliatic oceanic suture; and (3) north-dipping reflectors interpreted as remnant Hercynian lithotectonic fragments with opposed vergency to the subducted Alpine units.  相似文献   

Monitoring changes in shoreline position adjacent to the Hadera power station, Israel   总被引：1，自引：0，他引：1  

Micha Klein  Michal Lichter 《Applied geography (Sevenoaks, England)》2006,26(3-4):210-226

The paper focuses on the shoreline changes following the construction of a power station cooling harbor in Hadera, Israel, and uses a statistical analysis method capable of mitigating the effect of short-term changes on the measurement of long-term changes. The changes in shoreline position detected 25 years after the harbor's construction were compared with forecasts of the Central Lab for Hydraulics of France (LCHF) in 1976, which correctly predicted the effects of the construction on the nearby coast and with studies conducted a few years after the construction. A comparison between later studies and the study described herein shows a spatial effect of the harbor on shoreline position of 750 m north of the northern breakwater. No effect was found south of the harbor. The harbor's temporal effects extend over a few years from the beginning of the construction until the coast reaches a new sedimentary equilibrium. The statistical analysis method employed was found useful for the detection of long-term changes in shoreline position such as those caused by the construction of coastal structures; it will not be suitable for the detection of long-term changes resulting from a rise in sea-level.  相似文献   

Analytical expressions for Fresnel volumes and interface fresnel zones of seismic body waves. Part 2: Transmitted and converted waves. Head waves     

Michal Kvasnička  Vlastislav Červený 《Studia Geophysica et Geodaetica》1996,40(4):381-397

Summary Fresnel volumes and interface Fresnel zones of transmitted and head waves are studied. The relation derived for transmitted waves may also be used for converted reflected waves. Considerable attention is devoted to the penetration of Fresnel volumes across structural interfaces, particularly for head waves.  相似文献   

High density neighborhoods: Who enjoys them?     

Michal?MitranyEmail author 《GeoJournal》2005,64(2):131-140

To date, research into the subjective aspects of high density has focused mainly on the negative consequences of overcrowding. This study, in contrast, outlines some of the positive aspects of high density in neighborhoods, exploring the physical–spatial environment of two neighborhoods in the city of Haifa, Israel. It was found that while the relatively high residential density was similar in both neighborhoods (40 housing units per acre), this was more positively evaluated in one neighborhood as compared to the other. This can be attributed to some specific environmental and planning features. In particular, where physical planning enabled the potential advantages of high density to be realized, this was positively perceived and evaluated by local residents. Such advantages mainly comprised accessibility to a variety of services, more frequent public transportation, and access to open spaces within walking distance. Particularly advantageous were the increased opportunities for social gathering. At the same time, however, high density did not foster social relationships on the neighborhood level. The study further identified the gender and age groups that benefited most from the high density. Thus, women evaluated high density more positively than men. Young families with children and senior citizens (over 65) were also more likely to benefit, and to evaluate the high density environment more positively than other social groups.  相似文献   

From rags to riches? Migration and intergenerational change in London's housing market, 1971–91     

Michal Lyons  John Simister 《Area》2000,32(3):271-285

Summary In 1971 under half of London's young people, then living with their parents, lived in households that owned their homes, while well over half lived in rented housing. By 1991, now no longer living with their parents, less than a quarter of these young people were tenants. This paper identifies the components of that intergenerational tenure mobility, distinguishing between home ownership in more, and less, 'desirable' wards, and quantifies the role of migration in mediating the overall changes in Londoner's housing market status between 1971 and 1991. It analyses the moderating factors contributing to housing status mobility, such as labour market mobility and household type, and assesses the differential impact of these processes on men and women. ONS Longitudinal Study data for the period 1971–91 are analysed. Findings are that the aggregate changes concealed a range of housing careers. In particular, in-migrants fared less well in the London housing market than in its labour market.  相似文献   

The impact of changing subcanopy radiation on snowmelt in a disturbed coniferous forest     

Ondrej Hotovy  Michal Jenicek 《水文研究》2020,34(26):5298-5314

Understanding the role of forests on snowmelt processes enables better estimates of snow storages at a catchment scale and contributes to a higher accuracy of spring flood forecasting. A coniferous forest modifies the snowpack energy balance by reducing the total amount of solar shortwave radiation (SWR) and enhancing the role of longwave radiation (LWR) emitted by trees. This study focuses on changes in SWR and LWR at three sites with different canopy structure (Bohemian Forest, Czechia), including one site affected by the bark beetle (Ips typographus). Measurements of incoming and outgoing SWR and LWR were performed at all sites equipped with CNR4 Net Radiometers for three cold seasons. In addition to SWR and LWR, sensible and latent heat, and ground heat and energy supplied by liquid precipitation were calculated. The results showed that net SWR at the healthy forest site represented only 7% of the amount at the open site due to the shading effect of trees. In contrast, net LWR represented a positive component of the snowpack energy balance at the healthy forest site and thus contributed the most to snowmelt. However, the modelled snowmelt rates were significantly lower in the forest than in the open area since the higher LWR in the forest did not compensated for the lower SWR. The progressive decay of disturbed forest caused the decrease in mean net LWR from −3.1 W/m² to −12.9 W/m² and the increase in mean net SWR from 31.6 W/m² to 96.2 W/m² during the study period. These changes caused an increase in modelled snowmelt rates by 50% in the disturbed forest, compared to the healthy forest site, during the study period. Our findings have important implications for runoff from areas affected by land cover changes due to either human activity or climate change.  相似文献   

M. Coltorti,H. Downes,M. Grégorie,S.Y. O'Reilly (eds): Petrological evolution of the European lithospheric mantle     

István Kovács 《Bulletin of Volcanology》2011,73(7):935-936

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