The newest geochemical and sedimentological studies of the Libkovice Member in the Most Basin revealed existence of a sedimentary cyclicity that is controlled by the change of Earth's orbital parameters and the shape of its orbit. The main objective of this study is to verify the hypothesis whether there is also a similar cyclical record in strata underlying the Libkovice Member. This interval located in top of the Holešice Member consists of lacustrine sediments of a smaller extent represented by the so-called Břešťany Clays. The aim of the diploma thesis was a geochemical analysis of the concentration of selected elements measured by a mobile XRF device from the drilling cores in the stratigraphic interval between the roof of the Main Coal and the base of the Libkovice Member. Also made was a litological description of boreholes and sedimentary texture of selected clay samples. A mineralogical analysis was performed using the X-ray diffraction method. Usefulness of the XRF mobile device was proven especially for the heavier elements (e.g., Fe and Sr) and less for the lighter elements K and Ti. Nevertheless, it was possible to assign the analysed sediments to the already published chemostratigraphic subdivision of the Most Basin and to confirm its validity. The Břešťany Clays horizon was identified...

A model study about the precise stratigraphy of the Kralodvorian Formation was made on the drill core from Ořech near Prague. The exposure at Levín was used as a reference section. Both sections were sedimentologicaly studied and described in detail. The study of thin sections was a supplemented for exact description of the rocks and lithotypes. Chemostratigraphic methods (?13C and TOC) and method of the rock magnetic susceptibility were used for detailed stratigraphic analyse. All the mentioned methods of both sections. Samples for the measurements of the magnetic susceptibility were taken by 0.5 m of thickness. The measurement of ?13C and TOC was taken from the non-wheathered 80 m of the drill core Ořech and from the upper 20 m Králův Dvůr Formation at Levín profile by 2 m. The available data show that Ořech represents low and middle part of the Kralodvorian strata and that all studied thickness (80 m) belongs to only positive excursion of ?13C. This excursion is interpreted to be the upper Katian. It gives an evidence that sedimentation of the Kralův Dvůr Formation was very fast. Identification and interpretation of this excursion makes possible the accurate interregional corelation of the strata. A precise regional stratigraphic subdivision is based on inhomogenities caused by different materials or...