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Földtani Közlöny145. köt. 2. sz. (2015.)


  • Bíró Lóránt ,
    Molnár Elemér :

    Abstract: The aim of this work was the ore genetical investigation of the primary oxidized manganese ores in Bakony Mountains (Csárda Hill: Úrkút, Eplény) by the trace and rare earth elements. The main question was that the genetics of the primary oxidized manganese ores and the oxidized manganese ores in Eplény and in Csárda Hill are the same or not from the genetical point of view.

    We calculated the enrichment factors of the trace and rare earth elements, the rare earth anomalies, the enrichment of the middle rare earth elements and the fractionation values of the rare earth element groups.

    According to the parametres the primary oxidized manganese ores samples are of hydrothermal origin, although the rare earth element concentration of the waad samples is very high which refers hydrogenous origin with strong hydrothermal effect. The primary oxidized manganese ores (Csárda Hill, Eplény) are the same in genetical aspect.

    Keywords: Transdanubian Range, Úrkút, Eplény, Csárda Hill, primary oxidized manganese ore, rare earth elements

  • Katona Lajos ,
    Magyar Imre ,
    Berta Tibor ,
    Varga András ,
    Sztanó Orsolya :

    Abstract: The Pannonian (Late Miocene – Early Pliocene) Tihany Member (formerly Tihany Formation) was deposited in the littoral zone of Lake Pannon and in various deltaic environments. The embedded fossil mollusc fauna faithfully reflects the patchy environmental conditions, and encompasses a wide spectrum of ecological groups, from brackish littoral through freshwater to terrestrial molluscs. This paper gives a fairly complete illustration of the mollusc fauna of the Tihany Member in the Balaton region, based on the palaeontological investigation of two surface outcrops. The first outcrop is a 40 m-high section cut into the Papvásár Hill near Balatonfűzfő. Its mollusc fauna is outstandingly rich with 95 species. The lower part of the outcrop yielded some species that are characteristic of the sublittoral zone of Lake Pannon (Congeria praerhomboidea STEVANOVIĆ, Lymnocardium majeri (HÖRNES)). Mass occurrence of littoral brackish molluscs, such as Melanopsis, Viviparus, Theodoxus, Lymnocardium, Congeria and Unio in the overlying layers indicate gradual shoaling. The sedimentological characters reflect deposition above the wave base, in shallow, intensely agitated water. In the uppermost part of the section paludal layers prevail, with very diverse freshwater snail fauna and transported terrestrial snails. The entire section thus indicates gradual regression, starting from the zone of shallow but unrestricted brackish lacustrine environment in the delta plain through interdistributary bays and ending in seasonally flooded paludal environments. The 9 cyclothemes recognized in the section, however, reveals the cyclic nature of the overall regression process.

    The other outcrop is an artificial trench that we dug in a ploughland near Balatonalmádi–Vörösberény. The two fossilrich layers of the outcrop yielded 60 mollusc and 2 fish species, including some relatively rare forms. These layers were deposited above the wave base, in agitated and well aerated water, in a brackish lacustrine embayment on the delta plain. Their fauna is characteristic of the littoral zone of Lake Pannon. In this study we use a conservative taxonomic nomenclature, because we think that revision of the nomenclature should be preceded, and based on, a thorough taxonomic revision of Lake Pannon molluscs.

    Keywords: Lake Pannon, Pannonian Stage, Tihany Member, molluscs, palaeoecology, sedimentary facies

  • Tőkés Lilla ,
    Sztanó Orsolya :

    Abstract: Turbidity currents are able to travel hundreds of kilometres on the basin plain. However, the margins and floors of oceans, seas or lakes are rarely smooth. The topography can significantly alter the route of turbidity currents and thus modify the deposition of beds; this is termed as confinement. The earlier concepts of ponding and containment refer to turbidity currents completely trapped within a basin. Smaller alteration on turbidity current route also fits into the term of confinement. In general, confined turbidite beds are thicker and cover smaller areas than unconfined turbidites. The major characteristics of individual confined turbidite beds are defined from outcrops and cores. Palaeocurrent indicators showing different flow directions, renewed normal grading and thick mudstone caps are common features. Five types of reflected turbidite beds can be determined. Their characteristics mainly depend on the volume of the flow, the gradient of the slope and the relative position of the log and the slope. Turbidites and analog models indicate that turbidity currents can respond to a confining slope in different ways. They are able to travel upslope if the slope is not steep and high. Otherwise the flow will be reflected or deflected. Density stratified currents are prone to decoupling into a lower dense and an upper dilute part when meeting an obstacle. The lower part is deflected, the upper part is reflected or it surmounts the confining slope.

    Confined turbidites build specific turbidite systems. In general, the sedimentary fill of confined basins is cha rac - terized by upward increasing sand/mud ratio, decreasing rate of confinement and transition from lobe to channel deposits. The evolution of confined basins includes ponding, fill and spill — in other words, flow stripping —; bypass and erosion. Slope or basin floor topography is the most important factor influencing the evolution of confined basins. Since topo g - raphy is developed in response to structural deformation, the examples of confined basins are described here according to their plate tectonic setting.

    Keywords: confined turbidite basin, turbidity current reflection, turbidity current deflection, confined turbidites, evolution of confined basins

  • Kovács István ,
    Udvardi Beatrix ,
    Falus György ,
    Földvári Mária ,
    Fancsik Tamás ,
    Kónya Péter ,
    Bodor Emese ,
    Mihály Judith ,
    Németh Csaba ,
    Czirják Gábor ,
    Ősi Attila ,
    Vargáné Barna Zsuzsanna ,
    Harjit P. Bhattoa ,
    Szekanecz Zoltán ,
    Turza Sándor :

    Abstract: In this study a recently quickly advancing mode of FTIR spectrometry in earth and environmental sciences, the attenuated total reflectance (hereafter referred to as ATR) spectrometry, is introduced and compared to the widely applied transmission infrared (hereafter referred to as TIR) technique using KBr pellets. Through the presented results the authors wish to provide guidance in regard to what results could be achieved with the different analytical settings and technical parametres (i.e. types of detectors and ATR accessories). International clay mineral standards, siliciclastic sedimentary rocks, bones and ambers have been analyzed by different ATR accessories and detectors to constrain the optimal analytical settings. In addition, a summary for the assignment of characteristic absorption bands in the investigated materials is given providing a comprehensive overview for the Earth and Environmental Science applications of ATR FTIR spectrometry. Some practical domestic applications of ATR FTIR are presented including siliciclastic sediments from the landslide effected Kulcs area and ambers from Iharkút.

    Keywords: Fourier-transform infrared spectrometry, attenuated total reflection, vibrational spectroscopy of minerals

In memoriam

  • összeállította Cserny Tibor ,
    Palotás Klára :
    Hírek, ismertetések195-198 [83.78 kB - PDF]EPA-01635-00372-0090
  • összeállította Krivánné Horváth Ágnes :
    Társulati ügyek199-212 [202.39 kB - PDF]EPA-01635-00372-0100

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