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Chemical and Physical Properties of Impact Glasses
Křížová, Šárka ; Skála, Roman (advisor) ; Kohout, Tomáš (referee) ; Macháček, Jan (referee)
Abstract This work deals with microstructural features, chemistry and the search for traces of a meteoritic component in proximal tektite-like glasses from the Zhamanshin impact structure (Kazakhstan; further abbreviated as ZIS), and tektites from two strewn fields - moldavites (Czech Republic) and Australasian tektites (Laos; further abbreviated as AAT). Detailed microstructural observations and subsequent chemical and mineralogical studies of various types of inclusions were also performed; these inclusions were mostly found in the studied types of glasses for the first time ever. The aim of this PhD thesis was to (i) describe the microstructure of all studied glasses with a focus on yet unobserved microstructural phenomena, and (ii) try to determine the admixtures of meteoritic components in these glasses. In addition, the available target rocks, which could be a source of moldavites or AAT, were also studied. The microstructures of the studied glasses mutually differ. This is due to a diversity of parent materials and different glass formation conditions occurring during a particular impact event. A new type of "composite splash-form" has been identified among the ZIS glasses, whose chemical composition does not fit into the previously defined groups of irghizites or basic "splash-forms". For...
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Amphibian habitat preferences in selected localities after mining moldavites.
NĚMEC, Stanislav
This thesis pursues amphibian biotop preferences in locations where moldavites were quarried in the past. Field work took place in two localities near Trhové Sviny. The first one is situated near the village of Slavče where an illegal extraction still occures,.The second locality is found by the village of Dobrkovská Lhotka. This locality was partially recultivated in 2010. The aim of this work was to establish which factors do influence different amphibian species in the both studied locations. There were found five various species of amphibians near the village of Slavče: the Common frog (Rana temporaria), the Edible frog (Pelophylax kl. esculentus), the European fire-bellied toad (Bombina bombina), the European tree frog (Hyla arborea) and the Common toad (Bufo bufo). The results were statistically evaluated. Based on them it was established that the Common frog prefers the herb layer, the European Fire-bellied toad prefers semi shaded medium sized pools that do not dry up. The European tree frog and the Edible frog prefer large areas of pools and ponds. More over the edible frog demands ponds that are partially overgrown. The Common toad was represented only with one single individual. Therefore a statistical analasys could not be executed. The whole locality is negatively influenced by local inhabitants who gather here manure and organic waste from their gardens. On locality located near to Dobrkovská Lhotka was transformed from a mining landscape to a pond and three pools. All amphibian species that lived in the locality before reclamation were still present here. Occurrence of Common spadefoot (Pelobates fuscus) was confirmed by the unique finding of a tadpole. Statistical evaluation was not conducted due to the small number and variability of monitored sites.
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Issues of landscape conservation and mineral resources on the example of unregulated mining moldavites
HANUŠOVÁ, Judita
This work investigates the impact of illegal logging moldavites on selected environmental components. The aim was to assess the significance of adverse effects according to established criteria and subsequent evaluation. The assessment process was conducted in the village Slavče in South Bohemia in the period from April 2008 to March 2011. Adverse effects were evaluated mostly as long-term, but with the possible return to its original state. The work is to propose measures to improve the situation.
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