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Petrografická identifikace vulkanické horniny z vrchu Větrovec u Vysoké Lípy v NP České Švýcarsko
Adamovič, Jiří ; Mészárosová, Noemi ; Mikysek, Petr
Byla provedena petrografická analýza dvou vzorků vulkanitů odebraných z intruze v pískovcích jizerského souvrství na jihozápadním svahu vrchu Větrovec, kat. Vysoká Lípa. Pomocí optické mikroskopie, fázové analýzy metodou práškové rentgenové difrakce a bodových kvalitativních analýz jednotlivých minerálních fází na elekronovém mikroskopu s EDS detektorem byly popsány jednotlivé minerální fáze v obou vzorcích a zjištěny jejich obsahy a vzájemné vztahy. Hornina vzorku 1 je rhönitický olivinický bazalt s možnými přechody do rhönitického nefelinického bazanitu, hornina vzorku 3 je vesikulární rhönitický olivinický bazalt.
Origin and evolution of silcretes
Kohoutová, Iveta ; Zachariáš, Jiří (advisor) ; Adamovič, Jiří (referee)
Summary: Silcretes are rocks with high content of SiO2 (usually more than 90 wt. %) formed by mobilization of SiO2 during weathering processes. Silcretes formed near the Earth's surface by soil weathering in warm and humid climate are termed as pedogenic silcretes. Another type of silcrete is groundwater silcrete, whose origin is usually associated with the groundwater table and depths of 5-50 m below the surface and arid to semi-arid climate. The third type of silcretes is associated with evaporites. Its genesis is complicated; as well it is difficult to date this silicification. There are four types of silcrete textures: GS-, F-, M-, C- textures; the most common is the F-texture. In the Czech Republic silcretes are more known under the term "sluňáky" or "quartzite". Indeed, in every country where they occur, have their own specific name. Silcretes are essentially composed of SiO2, minor constituents represent heavy minerals and/or feldspar. Cement is mostly α-quartz, chalcedony and opal. Average thickness of silcretes is 1-3 m, rarely 5 meters. Main source of SiO2 is chemical weathering of silicate minerals or quartz dust grains carried by wind and deposited on natural barriers, like blades of grass. There are two models of silcrete formation: lateral and vertical transport model SiO2. Sedimentary...
Valley evolution of the Kladská Bělá river
Stemberk, Jakub ; Štěpančíková, Petra (advisor) ; Migoň, Piotr (referee) ; Adamovič, Jiří (referee)
The PhD. thesis deals with the morphostructural evolution of the valley network of the Biala Lądecka river, (further refer as BL) during the Late Cenozoic. In this work, the selected methods as geomorphological research (morphostructural analysis, geomorphological mapping), structural-geological research (paleostres analysis) and geophysical survey on selected sites were used, to answer the questions of river basin development and its relationship with predicted tectonic activity within the area, as well as with anticipated or already known paleohydrographic changes. The BL basin is situated within the Rychlebské hory Mts. / Góry Złote (northern and eastern parts of the basin), Králický Sněžník (southern part) and the Krowiarki Mts. (western part) in Poland. The Marginal Sudetic fault zone, which represents one of the most important tectonic zones in the Central Europe, passes in vicinity of the study area as well as the regionally important Bělský fault, which passes directly through the BL basin. The results of the analysis indicate that the BL basin has undergone very complex development due to tectonic movements since Miocene up-to-day. Based on the results of the paleostress analysis, which was performed on the dated volcanites in Lutynia - Lądek Zdrój area, the parameters of the palaostress...
Magnetic polarity in concretions
Smrčinová, Lucie ; Kletetschka, Günther (advisor) ; Adamovič, Jiří (referee)
Terrestrial iron oxides, such as hematite, goethite and magnetite, form specifically cemented concretions in sandstones using an aqueous diagenetic solution. According to the new results, the timeline on which concretions are formed could be much larger than current estimates. The basis for this claim is a magnetic record of the Jurassic Navajo Sandstone in Utah. The record contains fluctuations of remanent magnetization, which could prove the inversion of the Earth's magnetic field. This observation suggests that the time axis of the accumulation of iron concretions is comparable to the time axis of the accumulation of marine iron-manganese nodules, which contain a complex magnetic record. The occurrence of extremely slow changes in iron deposition in sandstones also helps to better understand the origin of concretions. In addition, terrestrial concretions provide an analogy for the "blueberries" found by the Mars rover Opportunity on Mars. These concretions probably underwent similar formation processes and could record inversions of the early magnetic dynamo on Mars.
Magnetic record of conretions
Smrčinová, Lucie ; Kletetschka, Günther (advisor) ; Adamovič, Jiří (referee)
Abstact The submitted bachelor thesis is focusing on the analysis of emergence of the concretion samples, which were discovered in recent years on the location of Jurassic Navajo Sandstone in Utah, and simultaneously their comparison with concretions found during exploration of Mars on the place Meridiani Planum. The major objective of this study is to compare the condition of origin and to search possible similarities. Terestrical concretions of iron oxid maintain diagenetical record of interaction between underground water flow and sandy material. Based on the input parametres, observed here, numerical and laboratory simulations were performed, leading to explanation of an image about growth of these spherules. Important factors during precipitation of nodules is concentation, flux and time. The experiment with reactions of ferrous sulfate, iron nitrate and potassium hydroxid shows the process of precipitation and maturation of hydrated iron around nucleation center of cencretion. Comparison laboratory results, numerical simulations and found samples helps to understanding to emergence of iron concretionson Mars in a certain chemical and hydrological environment. The importance of this contribution is, that on the basis of knowledge research about concretions, their both magnetical and geochemical...

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2 Adamovič, Ján
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