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  • Author or Editor: Tamás Budai x
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Partial and pervasive dolomitization of foreslope and toe-of-slope deposits of an early Carnian carbonate platform was investigated to understand the process and mechanism of dolomitization. Based on petrographic observations and C and O isotope data, the dolomitization took place in a near-surface to shallow burial setting; seawater of slightly elevated salinity was likely the dolomitizing fluid. The circulation system was maintained by reflux of evaporated sea water and geothermal heating of cold seawater derived from the surrounding deeper basin. The dolomitization was mostly controlled by the permeability of the platform-derived calcareous sediments.

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Abstract

Recent excavation and sampling in the upper part of the Felsőörs section (Balaton Highland, Hungary) yielded important ammonoid findings, identified as belonging to the genera Nevadites, Chieseiceras, Eoprotrachyceras and Falsanolcites. Several specimens of Chieseiceras chiesense were found in a dm-thick clay layer with limestone nodules, regarded as the equivalent of the “Chiesense Groove“ of the Bagolino and other sections in the Giudicarie area (North Italy). The immediately overlying limestone bed yielded Eoprotrachyceras cf. curionii and Falsanolcites cf. rieberi. Together these reliably prove the base of the Curionii Zone, corresponding to the base of the Ladinian Stage, the GSSP of which was recently established at Bagolino. The new data further improved the excellent correlation between the ammonoid records of the Felsőörs section and the Global Stratotype Section at Bagolino. Felsőörs may be considered the most important reference section for the Anisian to Ladinian boundary interval.

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Sideritic—kaolinitic and green clay layers were previously reported from the Mecsek Mountains (SW Hungary) as indicators of Tethyan volcanism in the otherwise germanotype Middle Triassic succession. The aim of the present study is to provide a review and a critical re-evaluation of the previously published data on both the sideritic—kaolinitic layers (the so-called “Mánfa Siderite”) and the green clay layers. New results of mineralogical investigation of the green clay layers are also presented. The Middle Triassic volcanic origin of the “Mánfa Siderite” cannot be confirmed. In addition to a possible volcanic contribution, the sideritic—kaolinitic layers were probably formed in a freshwater swamp under humid, tropical climatic conditions, whereby weathering in an organic-rich, acidic environment led to the formation of “underclays” and siderite in the coal-bearing formations of Late Triassic to Early Jurassic age. These layers were probably tectonically placed over Middle Triassic carbonates. The illitic green clay layers intercalated in the Middle Triassic dolostone may represent terrigenous deposits, and the illite mineralogy probably is the result of burial diagenesis of detrital clays.

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The aim of this paper is to introduce the design steps and implementation details of a system, which combines modern web-technologies and open-source simulation software to create a virtual laboratory framework. In order to validate the functionality of this framework and to demonstrate its capabilities, a classic experiment from the field of control theory was implemented; the inverted pendulum. In this experiment, a simulated controller keeps the rod of the pendulum in an upright position. Users can change different parameters of the model and then test the impact of these changes in a very intuitive and interactive way, by applying force to the pendulum model in 3D and observing the behavior of the controller.

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The Middle Triassic Wetterstein Limestone was investigated on the Feuerkogel, in the eastern Höllengebirge area, Austria. Cephalopod-bearing coquina interbeds consisting predominantly of orthocone cephalopods were found within the dasycladacean inner platform lagoon facies. Based on sedimentological studies the coquina beds are interpreted as storm accumulations. Dasycladacean biostratigraphic data permit assigning the studied succession to the Late Anisian-Early Ladinian interval. Ammonites of age-diagnostic value found in the coquina horizon suggest the Avisianum Subzone of the Reitzi Zone that corresponds to the upper part of the Anisian.

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Authors: Mateu Esteban, Tamás Budai, Erika Juhász and Philippe Lapointe

Abstract

Large, irregular volumes of altered, friable Triassic dolomite with poorly recognizable depositional fabrics crop out in the Buda Mountains, Hungary. These rock volumes are characterized by powder-like, chalky, soft, whitish gray microporous carbonates, referred to as “pulverized dolomite”. This is interpreted as the result of corrosion of carbonates along microfractures. The pulverized dolomite is commonly associated with silica and clay cementation (“silicification”) and “mineralization” of ironrich minerals, barite, sphalerite, galena, fluorite, calcite, dolomite and others, clearly pointing out hydrothermal Mississippi Valley Type (MVT) conditions.

The pulverization, silicification and mineralization are considered to be a diagenetic facies association (PSM facies). Tectonic shear corridors played an important role in the development of PSM facies as carriers of hydrothermal fluids, but the geometry of the altered units is very irregular and cross-cuts different Triassic depositional facies in addition to Eocene limestone and Middle-Upper Miocene sediments. The PSM facies represents the early stages of hydrothermal alteration (i.e. the burial phase) that was later modified by thermal mixing zones. Pulverized dolomite bodies that reached the surface were strongly affected by meteoric fluids; peculiar speleo-concretions were formed by calcite cementation of the powdery dolomite clasts.

The altered carbonates show major porosity development whereas the unaltered carbonates present only minor porosity. The size and lithologic contrast of the altered geobodies makes them detectable by geophysical methods of mineral and hydrocarbon exploration.

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Abstract

In the Pilis Range, NW of Budapest, contemporaneous Upper Triassic platform and basin facies occur. The paper presents the extent and basic characteristics of these facies with interpretation of their depositional conditions, and summarizes the available biostratigraphic data. Based on previous and recent studies a general depositional model is displayed and the history of the basin evolution is outlined. Within the Dachstein Platform an extensional intraplatform basin (Feketehegy Basin) came into existence during the middle part of the Norian. An asymmetric basin was formed, bounded by steep and gentle slopes, respectively. The platform progradation that may have resulted in the termination of the basin began at the gentle margin probably in the latest Norian-earliest Rhaetian.

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Authors: Miklós Kuczmann, Tamás Budai, Gergely Kovács, Dániel Marcsa, Gergely Friedl, Péter Prukner, Tamás Unger and György Tomozi

In the frame of the project TÁMOP 4.2.2.A, at the Széchenyi István University, the goal is to work out a new finite element package for the simulation and optimization of permanent magnet synchronous motors. These motors are then used to drive new electric cars. The aim of the two dimensional package is the fast numerical modeling of these electric devices by the use of free tools presented in the paper. Of course, the software is aimed to use it in the simulation of other devices, and three dimensional problems, as well.

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Authors: Imre Boncz, Andor Sebestyén, Lajos Döbrőssy, Attila Kovács, András Budai and Tamás Székely

A dolgozat célja annak meghatározása, hogy Magyarországon a nők hány százaléka vesz részt nőgyógyászati citológiai vizsgálaton (lefedettség), akár a szervezett szűrővizsgálat keretében, akár az egyéb nőgyógyászati vizsgálatok során. Adatok és módszerek: Az elemzés az Országos Egészségbiztosítási Pénztár (OEP) rutinszerűen gyűjtött finanszírozási adatokat tartalmazó adatbázisára épül. A vizsgálatban a 2000 és 2002 közötti 3 éves periódus volt az opportunisztikus szűrés referencia-időszaka, míg a 2003 és 2005 közötti 3 év a szervezett szűrés első szűrési ciklusa. Eredmények: Míg a 2000 és 2002 közötti 3 évben 1 667 618 nőnél végeztek citológiai vizsgálatot, addig ez a szám 2003 és 2005 között 1 749 498 főre emelkedett. A 25–64 év közötti női korosztályban 2000 és 2002 között az 1 éves lefedettség 22,0–23,3% között változott, ami 2003 és 2005 között 23,4–24,3%-ra emelkedett. A 2000 és 2002 közötti 3 éves lefedettség pedig 48,9%-ról 2003 és 2005 között 52,6%-ra emelkedett a szervezett szűréssel érintett célpopulációban (+3,7%). Következtetés: A szervezett szűrés kismértékben növelte a citológiai vizsgálaton részt vevő nők számát. Ahhoz azonban, hogy érdemi mortalitáscsökkenést eredményezzen a program, a részvételi mutatókat növelni szükséges.

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Authors: János Haas, Tamás Budai, István Dunkl, Éva Farics, Sándor Józsa, Szilvia Kövér, Annette E. Götz, Olga Piros and Péter Szeitz

The 1,200-m-deep Budaörs-1 borehole provided important data for our understanding of the stratigraphy and tectonic setting of the southern part of the Buda Hills. Although previous reports contained valid observations and interpretations, a number of open questions remained. The importance of this borehole and the unsolved problems motivated us to revisit the archived core. The new studies confirmed the existing stratigraphic assignment for the upper dolomite unit (Budaörs Dolomite Formation) as the dasycladalean alga flora proved its late Anisian to Ladinian age assignment. An andesite dike was intersected within the Budaörs Dolomite. U–Pb age determination performed on zircon crystals revealed a Carnian age (~233 Ma), and settled the long-lasting dispute on the age of this dike, proving the existence of a Carnian volcanic activity in this area after the deposition of the Budaörs Dolomite. Palynostratigraphic studies provided evidence for a late Carnian to early Norian age of the upper part of the lower unit (Mátyáshegy Formation). This result verified an earlier assumption and reinforced the significance of the tectonic contact between the upper unit (Budaörs Formation) and the lower unit (Mátyáshegy Formation). Based on structural observations and construction of cross sections, two alternative models are presented for the structural style and kinematics of the contact zone between the Budaörs and Mátyáshegy Formations. Model A suggests a Cretaceous age for the juxtaposition, along an E–W striking sinistral transpressional fault. In contrast, model B postulates dextral transpression and an Eocene age for the deformation. The latter one is better supported by the scattered dip data; however, both scenarios are considered in this paper as possible models.

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