Sándor Kovács

Significance of Late Permian-Triassic facies zones in terrane reconstructions in the Alpine-North Pannonian domain

Abstract The present-day setting of the tectonic units (terranes) making up the pre-Neogene basement of the Pannonian Basin and the West Carpathians is the result of large-scale displacements during the Alpine collisional phases. To explain this setting, based on various concepts, a number of models have been proposed in the last decade. Most of them agree in an eastward escape of the “North Pannonian terrane” from the Alpine domain towards the Pannonian during the Palaeogene-Early Miocene period. In the present paper a reconstruction of the pre-escape setting of the displaced terranes is presented based on facies zones in selected time-slices from the Late Permian to the Late Triassic. According to our reconstruction the Inner West Carpathian units were located east of the Austroalpine units forming the northern shelf of the “Euhallstatt”-Meliatic basin of the Vardar oceanic branch. The Drauzug should have been located in a position much more external than its present-day setting. The Transdanubian Range was situated in the northern neighbourhood of the Southern Alps, whereas the Bukk may have been located adjacent to the NW Dinarides. The Mid-Transdanubian zone is a major shear-zone containing elements of the Julian Alps and Sava folds nappe system and the Inner Dinaric ophiolitic melange. Although the nappe-tectonism may have played an important role in the structural evolution of the “North Pannonian terrane”, this mechanism alone can hardly produce hundreds of kilometres of facies offset on the opposite sides of strike-slip zones.

New radiolarian biostratigraphic age constraints on Middle Triassic basalts and radiolarites from the Inner Hellenides (Northern Pindos and Othris Mountains, Northern Greece) and their implications for the geodynamic evolution of the early Mesozoic Neotethys

The Avdella Mélange in the northern Pindos Mountains and its equivalent formation, the Loggitsion Unit in the Othris Mountains expose early Mesozoic (Mid-Late Triassic) oceanic fragments beneath the Western Greek Ophiolite Belt of the Inner Hellenides, Northern Greece. The mélange consists of locally interfingering blocks and slices of ribbon radiolarite, radiolarian chert and pillow basalt and is usually overthrust by Jurassic ophiolites. New Middle and Upper Triassic radiolarian biostratigraphic data are presented from radiolarites and basalt-radiolarite sequences within mélange blocks. Pillow basalts associated with the radiolarites provide clues to the opening of the Neotethyan ocean basin. The radiolarians indicate a Middle Triassic age (latest Anisian, probably early Illyrian), which is documented for the first time in the northern Pindos Mountains. The new radiolarian biostratigraphic data suggest that rift-type basalt volcanism already began in pre-Ladinian time (late Scythian?—Anisian). These basalts were then overlain by Upper Anisian to Carnian (?Norian) radiolarites.

Deformation history and nappe stacking in Rudabánya Hills (Inner Western Carpathians) unravelled by structural geological, metamorphic petrological and geochronological studies of Jurassic sediments

Several Jurassic tectonic units of the Rudabánya Hills (Inner Western Carpathians) were studied by structural geological, metamorphic petrological and geochronological methods, in order to unravel its deformation history and nappe stacking. Three series showing pronounced lithostratigraphic similarities (black shale, sandstone turbidite and olisthostrome) are interpreted to be subunits of the Telekesoldal nappe. It is questionable whether a Triassic basement can be associated with these Jurassic rocks. Metamorphic petrological data indicate metamorphism at the transition between the high-temperature anchizone and epizone (300–350°C and 2-2.5 kbar pressure). These series were affected by three events of ductile deformation including in order 1) layer-parallel foliation, 2) folding with axial plane foliation and 3) kink bands. K-Ar ages suggest that the main detected metamorphic event took place about 137–117 Ma ago. In contrast, the uppermost Triassic–Jurassic Telekesvölgy, and the Triassic Bódva series were only affected by diagenetic (partly anchimetamorphic) alteration. The metamorphosed Jurassic complexes thrust upon the Telekesvölgy–Bódva sequence as a separate nappe at 87–94 Ma as suggested by K-Ar data. The metamorphism and deformation of these Jurassic series are suggested to appear simultaneously with the Middle Jurassic–earliest Cretaceous subduction of the Meliata branch of the Neotethys Ocean. Post-metamorphic deformation, including nappe emplacement seems to be coeval with mid-Cretaceous deformations of other Inner Western Carpathian units. The latter is probably related to the closure of the Penninic-Vahic Ocean farther to the north.

Dissociative ionization of the H2 O molecule induced by medium-energy singly charged projectiles

We report on the fragmentation of the water molecule by

Comparison between anion and cation emission from CH4 molecules colliding with 10.5-keV C+ ions: Fragment-energy aspects

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Anion emission from water molecules colliding with positive ions: Identification of binary and many-body processes

MeV H

Conductivity mechanism probed by ion transmission through nanocapillaries during the discharging process

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Two- and many-body effects in cation emission from H2O molecules by O+ impact at keV energies: Similarities between ionization of atoms and proton emission from molecules

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Induced ionization of small molecules: comparison of experiment with quantum and classical calculations

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Blocking effect on transmission of Ne7+ ions through nanocapillaries

and 650 keV N