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Tectonic and metamorphic evolution of the Tokar-Barka Terrain (East-African Orogeny)
Hořenínová, Marie ; Verner, Kryštof (advisor) ; Peřestý, Vít (referee)
in English This bachelor's thesis summarizes the tectonic and metamorphic evolution of the Tokar-Barka Unit in the southern part of the Arabian-Nubian Shield. The compilation includes an information of regional division, lithological pattern, age, deformation structures and record of metamorphic evolution, mainly in the context of East African orogenic processes. The main episodes of geodynamic evolution are briefly discussed in a regional context. Key words: East-African Orogeny, Arabian-Nubian Shield, Tokar-Barka Unit, Deformation, Tectonics, Metamorphic evolution
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Metamorphism and geodynamics of the Proterozoic Kabul Block: Preservation and modification of crustal fragments within an orogenic zone
Collett, Stephen ; Faryad, Shah Wali (advisor) ; Kotková, Jana (referee) ; Krenn, Kurt (referee)
The Kabul Block is a lenticular crustal fragment that, along with the Farah, Helmand, and Nuristan terranes, is situated within a tectonic zone known as the Afghan Central Blocks. The Afghan Cent- ral Blocks form within the collision zone between the Indian, Eurasian, and Arabian plates. The Kabul Block consists of a highly-deformed crystalline basement overlain by weakly-deformed Late Paleozoic- Mesozoic sediments. U/Pb SHRIMP analysis of zircon cores from the lowermost basement formations (the Sherdarwaza and/or Khair Khana) indicates the presence of a Neoarchean component (~ 2700 Ma), while the majority of zircon cores yield a range of Early Paleoproterozoic ages (2200 - 2500 Ma). The Sherdarwaza and Khair Khana Formations are comprised of migmatite and orthogneiss with minor marble, quartzite, and amphibolite that reached granulite-facies conditions. Conventional geother- mobarometry and phase equilibria modelling on well preserved granulite-facies assemblages indicates that the rocks reached conditions of approximately 850 řC at up to 7 kbar of pressure. Textural relations indicate that this was a strongly temperature dominated event. U/Pb SHRIMP dating of zircon rims and U-Th-Pb dating of monazite inclusions in granulite-facies garnet suggest that this event occurred in the late...
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Variscan igneous activity at the Bohemicum/moldanubicum boundary
Kubínová, Šárka ; Holub, František (advisor) ; Pertoldová, Jaroslava (referee)
Variscan dike swarms associated with the Central Bohemian Plutonic Complex (CBPC) at the boundary between the Teplá-Barrandian and Moldanubian Units of the Bohemian Massif represent one of the most interesting geological phenomena. Frequency of dykes and their chemical variability do not have any comparable analogy in the whole European Variscides. This work is focused on the study of dyke rocks in the NE periphery of CBPC in geologically very complicated area with intrusions of predominantly deformed granitoids, contact metamorphosed sediments and magmatic rocks of "Islet Zone" with different protolith ages (forming remnants of the original roof of CBPC), deformed basic rocks of uncertain origin and age. The area extends up to the western boundary of the northernmost part of the Moldanubian high-grade metamorphic complex, the boundary itself being also tectonically problematic. Several localities with dyke rocks under study are situated in the area east of Senohraby (SE of Prague), on the northern side (right coast) of the Sázava river, and extend up to the area of Stříbrná Skalice. This area is rich in dykes of gabbro to diorite porphyry accompanied in some places with tonalite (rarely quartz diorite) porphyry and more rarely with amphibole lamprophyres (spessartite). Significantly younger dykes...
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Mineral assemblages and conditions of origin of metamorphic skarns in the Bohemian Massif
Bubal, Jan ; Dolejš, David (advisor) ; Pertoldová, Jaroslava (referee)
ENGLISH SUMMARY MINERAL ASSEMBLAGES AND CONDITIONS OF ORIGIN OF METAMORPHIC SKARNS IN THE BOHEMIAN MASSIF Calcic-iron skarns are a characteristic rock type of regional metamorphic complexes wirkude. In the Bohemian Massif, characteristic enrichment in Ca, Al, and Fe as well as mineral assemblages, textures are similar to their contact metamorphic counterparts but their origin remains unclear. In this thesis, we document petrography, mineral assemblages and chemistry of skarns and apply phase equilibrium models to reconstruct conditions of their formation. Skarns at Vlastějovice (Moldanubian zone), Malešov (Kutná Hora complex) and Měděnec (Saxothuringian zone) contain primary assemblage of garnet, clinopyroxene and magnetite, followed by crystallization of amphibole, epidote, formation of carbonate veins, and silicification. Some of these phenomena are related to the emplacement and fluid release from dykes of granitic pegmatites. Garnet represents the most abundant rock-forming minerals. Primary fine-grained aggregates (Gr30-50Alm30-40And10-30) are often recrystallized into euhedral grains or monomineralic masses with preserved chemical zoning (Gr05-30Alm1-30And40-90). At the Měděnec locality, garnets evolved towards andradite-skigaite composition. Clinopyroxene belongs to the diopside-hedenbergite series,...
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Zobecnění objektově orientovaného paradigmatu zavedením morfologie objektů
Šlajchrt, Zbyněk ; Pecinovský, Rudolf (advisor) ; Merunka, Vojtěch (referee) ; Virius, Miroslav (referee)
Modeling protean objects, i.e. objects adapting their structure and behavior dynamically with respect to a changeable environment, is often challenging in traditional object-oriented languages. According to the author, the root cause of this problem lies in the class-based conceptual framework embedded in the foundation of the object-oriented para-digm. The proposed paradigm Object Morphology (OM) is greatly influenced by prototype theory developed in the field of cognitive psychology. OM abandons the notion of class and suggests, instead, that the abstractions of protean objects should be established through the construction of morph models describing the possible forms of those objects. This the-sis defines the theoretical foundations of OM, which is further used to specify the elements of prototypical object-oriented analysis. An important part of this work is also a proof-of-concept implementation of an OM framework in Scala.
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