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Nautiloidea of Upper Cretaceous epicontinental seas in Europe
Frank, Jiří ; Košťák, Martin (advisor) ; Turek, Vojtěch (referee) ; Schlögl, Ján (referee)
The post-Triassic Nautiloidea are not as popular theme within fossils cephalopods research as for example ammonites. They are not very abundant in the fossil records except some rare localities and areas, their morphology is quite conservative and due to the usually poor preservation, their determination and assigning to the species even to genera level is often complicated. Exceptional are taxa with very specific morphology and short stratigraphic and endemic occurrence, which are even suitable for biostratigraphic interpretations. Problematic is also the often poor taxonomical representation of the type material and revision of many taxa is needed. Still nautilids are often represented by reasonable amount in the paleontological collections of natural history museums due to the long history of fossils collecting. Also the scientific literature has been dedicating at least some space to this group since 19 century. The aim of this study is to create an overview about the post- Triassic, especially Upper Cretaceous nautiolidea in the European region of epicontinental seas and prepare a good basement for extensive study of this group. Due to this aim the study is primarily focused on determination of morphological features and also problematic with their interpretation according to the variable...
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Genesis and paleogeographic significance of the clastic bands in the main coal of the Most Basin
Novotný, Tomáš ; Opluštil, Stanislav (advisor) ; Rojík, Petr (referee)
This diploma thesis presents first systematic geochemical a petrographical research of clastic bands in the lower-miocene Main Coal of the Most Basin. The main target of the thesis is evaluation of proxy analyses (EDXRF) of clastic bands and ash yield from coal. This method allows for identification of paleogeographic information about provenance of clastics derived from two different sources. The first source area represents weathered Tertiary volcanoclastics and the second is derived from crystalline basement in southwest part of the Bohemian Massif. Different geochemical signal of these two source areas detected in clastic bands allowed to constrain the switching of provenance into the lower part of the middle bench of the Main Coal in the Bílina open-cast mine whereas in the Doly Nástup-Tušimice mine this change occurs below the Main Coal. This result corresponds with idea of gradual changing of provenance across basin. Anomalous geochemical composition characterised by apparently increased content of Sr-Ba-P-Ca elements in one of clastic bands in the lower part of the Main Coal exposed in the Doly Nástup-Tušimice open-cast mine is related to presence of phosphate group minerals florencite and woodhouseite minerals as confirmed by RTG diffraction. This assemblage suggests possible admixture of...
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Cephalopods and biostratigraphy of North Bohemian Jurassic sediments
Hrbek, Jan ; Košťák, Martin (advisor) ; Ziegler, Václav (referee)
The Jurassic ammonites from the Northern Bohemia has been revised on the base of the material stored in the National Museum in Prague and the Faculty of Science, Charles University in Prague. 23 species and 19 genera, belonging to 7 families were described on the basis of this systematical revision. This ammonite assemblage indicates a proportional occurence of the Boreal, Tethyan and also cosmopolitan taxa. Stratigraphically important taxa suggest a considerably longer period of sedimentation, predominantly represented by the Upper Jurassic carbonates. This interval may contain up to 9 ammonite zones. A pilot microfacial analysis of carbonates from Peškova stráň area (in Krásná Lípa vicinity) indicates a considerably higher variability of sedimentation area. The presence of micritic carbonates suggests the existence of a widespread areas in the Late Jurassic sea covering the Bohemian Massif. The biostratigraphy and palaeogeography is briefly discussed in the European Late Jurassic context. Key words: ammonites, Upper Jurassic, Northern Bohemia, carbonate sediments, biostratigraphy, palaeogeography
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