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Alluvial gold placers from Klínec area - morphology and nature of gold
Fox, Simon ; Zachariáš, Jiří (advisor) ; Štědrá, Veronika (referee)
The search for economically viable gold deposits remains a significant pursuit requiring skilled expertise. The first part of the thesis establishes essential concepts related to gold ore deposits and placer gold, including its elemental properties, genesis in an orogenic environment, transportation by natural forces, and deposition in a fluvial setting. The study particularly focuses on the Klínec area in Central Bohemia and offers an insight into the geological region characterized by a Neoproterozoic basement uplifted during the late Miocene due to tectonic movements that played an integral role in the placer gold deposition. The historical context of gold mining in this Bohemian region is also presented. The practical segment of this thesis aims to establish connections between statistical and observational methods and the relationship between placer gold and its orogenic gold deposit. The methodology involves fieldwork for collecting gold particles which were then subjected to optical observation and microscopic photography. Morphological features, particularly sphericity and roundness, are analysed to identify trends indicating proximity to the primary gold source. The findings reveal that gold particles closer to the primary source exhibit sharper angularity, larger grain size, and greater...
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Structural and metamorphic evolution of thermal aureole of the Krkonoše-Jizera Plutonic Complex
Olšanská, Irena ; Verner, Kryštof (advisor) ; Štědrá, Veronika (referee)
Krkonose-Jizera plutonic complex is one of the largest composite plutonic bodies in the Czech massif. The emplacement of this pluton relates to the origin of the structural and thermal aureole. The processes of contact metamorphism are most evident in the northern and southern part. The topic of this work is to find influence of the contact metamorphism in the host rocks. Partial information about contact metamorphism in this area could be found in several papers, but there aren't work which discuss this topic in detail. Goal of this work is to make complex interpretation of contact metamorphic processes connected with intrusion of the Krkonose-Jizera plutonic complex and use this interpretation for discussion about model of magma intrusion. In rocks of contact aureole of Krkonose-Jizera plutonic complex (KJPC) were identified relicts of Variscan regional metamorphism, connected to creation of regional metamorphic fabric S1 and S2. Original mineral associations and deformation fabrics were in near-contact zone of KJPC 1 km in average in width heterogeneously overprinted by effects of the contact metamorphism, which intensity increases towards the intrusive contact. In the mineral associations of contact-metamorphic rocks appears characteristic minerals such as cordierite and andalusite, rarely...
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