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Mechanisms of granite fracturing and their implications for origin of gold-bearing veins in Mokrsko deposit
Švagera, Ondřej ; Lexa, Ondrej (advisor) ; Franěk, Jan (referee)
The stress concept in geology is widely used for analysis and description of tectonic events. These can be documented directly in the field or by interperetation of results gained by laboratory analysis. The expressions of brittle tectonics and geological events linked with them are often important clues leading to understanding processes giving unique forms to many localities. The origin of gold-bearing veins in Mokrsko deposit is result of long-lasting tectonic processes. During these were created at least 4 generations of brittle structures. The proximity of Variscides is the source of this brittle fracturing. Sázava pluton intruded during the syn- orogenic phase and in the Slapy apophysis of Sázava pluton started the circulation of fluids because of the contact metamorphism. These fluids were using pre-existing EW joint systems. After that, the precipitation of minerals rich in Bi-Te-Cu gave origin to the local gold-bearing mineralization. This mineralisation is partly bound to the quartz-veins localized on Mokrsko- Západ. Their thickness is often in sub-milimeter scale with very regular spacing.
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Geodynamic evolution and emplacement of Eisgarn - type granitoids (Moldanubian Batholith)
Paclíková, Jana ; Verner, Kryštof (advisor) ; Franěk, Jan (referee)
English abstract This diploma thesis deals mainly with identification of magmatic (respectively magnetic) fabrics, geodynamical aspects of emplacement and geochronology of the Eisgarn granitoids. For the analysis Klenov and Mrákotín pluton were chosen, which is placed in the eastern part of the Moldanubian Batholith. This thesis contains petrological and mezoscopic structural analysis of the host metamorphic rocks of the Moldanubian Unit and it includes calculation of P-T conditions of the main mineral assemblage. This is followed by petrological, geochemical and mezoscopic structural analysis of the Klenov and Mrákotín pluton and analysis of the anisotropy of magnetic susceptibility, geochronology of the Klenov pluton, gravimetry analysis and determination of the orientation of density interfaces in different depths. Granitoids of the Klenov and Mrákotín pluton are characterized as S-type granitoids, whose protolith were probably metasedimentary rocks. From the analysis it is also evident that the Klenov pluton records lower degree of magma fractionation than the Mrákotín pluton. The emplacement and crystallization of both studied magmatic bodies took place in cooperation with a development of regional metamorphic fabrics, which originate between 329 and 327 Ma. During this period a rapid exhumation of...
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Structural evolution of infra- and superstructure boundary in orogens
Peřestý, Vít ; Lexa, Ondrej (advisor) ; Franěk, Jan (referee)
ENGLISH ABSTRACT This work focuses on structural and deformational aspects of the crust development during orogeny, based on historical suprastructure/infrastructure concept. The uppermost suprastructure is dominated by steep fabrics, which evolved in a brittle regime within early stages of orogeny, and which sustain almost unchanged for the whole period of orogenic evolution. On the other hand, the infrastructure is located in the lower crust, where ductile processes dominate. Because the ductility is a thermally activated process, sufficiently long time is needed to heat the lower crust, and therefore the infrastructure is younger than suprastructure. Gently to shallowly dipping structures develop as a consequence of ductile flow. The aim of this study is to describe processes on the suprastructure/infrastructure boundary. Position of this boundary is closely related to brittle/ductile transition, and so that a brief introduction to rheology is included. Rheological boundaries are often places of high strain and high displacement gradients, which must be somehow accomodated. One possibility is to lose communication between adjacent levels and create a detachment plane, which is commonly supposed in the conventional thrust tectonics model. The other possibility is, that layers are at least partially...
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Subduction-driven shortening and differential exhumation in a Cadomian accretionary wedge: The Teplá?Barrandian unit, Bohemian Massif
Hajná, Jaroslava ; Žák, Jiří (advisor) ; Franěk, Jan (referee)
2. English abstract This doctoral thesis is focused on analysis of tectonic deformations a geodynamic evolution of Neoproterozoic and Lower Paleozoic rocks of the Teplá−Barrandian Unit along the northwestern margin of the Prague basin (central Bohemian Massif). Using a wide range of modern methods, correlation of finite deformation patterns in different units allowed separation of structures formed during Cadomian and Variscan orogeny and interpretation of tectonic processes and tectonic history of the Cadomian orogenic belt during late Neoproterozoic. The research found direct evidence for and enabled new interpretations of Cadomian tectonic processes in the Bohemian Massif, including a succesion of deformation phases, quantification of finite deformation gradients and mechanisms. The different data sets were finally combined into an overall geotectonic model of Cadomian orogeny and its Variscan tectonothermal overprint in the Bohemian Massif, as well as the data were used for correlation with other Avalonian−Cadomian terranes. 5
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Tectonic evolution of the Mariánské Lázně Complex and of surrounding units
Hafoudh, Shumran ; Konopásek, Jiří (advisor) ; Franěk, Jan (referee)
Tectonic evolution of the western margin of the Bohemian Massif is the result of southeastward Devonian subduction of the Saxothuringian Ocean followed by collision of the Saxothuringian continental crust with the easterly lying Teplá-Barrandian Domain during early Carboniferous (e.g. Franke 2000). Northwestern flank of the Teplá Barrandian Domain is represented by mafic and ultramafic rocks of the Mariánské Lázně Complex usually considered as an ophiolite complex documenting the closure of the Saxothuringian Ocean (e.g. Kastl &Tonika, 1984, Beard et al., 1994). Mariánské Lázně Complex is in the NW thrust over medium-grade metabasites and metasediments of the Kladská Unit with suggested Saxothuringian affinity (Kachlík, 1993), and in the SE it is overthrust by medium- to highgrade metasediments of the Teplá Complex (Cháb & Žáček, 1994). Geochronological data show that the northwestern flank of the Teplá-Barrandian Domain was exhumed already during Upper Devonian (Dallmeyer & Urban, 1998) and suggest apparent lack of deformation and metamorphism associated with Carboniferous collision. Our study has concentrated on structural record along the profile from the Kladská Unit to the Teplá Complex in order to separate structures produced during Devonian subduction and exhumation from those developed during...
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The optimization the production of selected medicinal substances
Fránek, Jan ; Ing.Oldrřich Smékal (referee) ; Omelková, Jiřina (advisor)
Mgr. Jan Fránek 2011: The optimization the production of selected medicinal substances The diploma thesis dealt with optimization of production of fingolimod by hydrogenation. During the optimization of production, there was reduction of benzylic hydroxygroup and nitrogroup of nitrofingotriol. Reduction of two different groups caused dividing process of hydrogenation into two phases. The original intention was to optimize production only in the autoclave, but the need of using acidic catalytical medium in first phase led to dividing the production into reduction in the reactor and following catalyzed hydrogenation, already in neutral conditions, in the autoclave. The way of preparation of active substance by using an autoclave had not been explored in detail before. Evaluation of optimization is a part of results. There are also production charges on pilot plant included in results. Because the results of procedure of the pilot unit were not uniform, it was necessary to continue in optimization even after finishing the production in pilot plant. Following procedure modified according to the latest experiments was passed to the operating process.
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