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Paleoenvironmental interpretation of elemental geochemical proxies of the borehole Jp 585: Lower Miocene lacustrine offshore clays of Cypris Formation, Sokolov Basin
Erlebachová, Alice ; Martínek, Karel (advisor) ; Opluštil, Stanislav (referee)
This thesis presents geochemical study of the Lower Miocene lacustrine offshore clays of the Cypris Formation in the Sokolov Basin of the Eger Graben aimed at paleoenvironmental reconstruction. The applicability of elemental geochemistry proxies in the interpretation of 94 m thick lithologically monotonous, offshore lacustrine clay succession of the well core Jp 585 is tested. Geochemical proxy data seems to be a good indicator of changes in source areas ,erosion rates and climate. XRF analysis shows for example decrease of detrital input and the increase in amount of authigenic silica and carbonates upwards in the section. The results of CEC analysis point to a rapid variations of expandable clay minerals content. Marked increase of CEC is at 40 m depth. Combination of XRF and CEC enabled suggesting of four chemostratigraphical units. Their boundaries are often sharp, pointing to rapid changes in lake metabolism. These changes are preliminary interpreted as climate changes.
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Study of xylitic wood of the Most Basin using the electron microscopy: systematics and palaeoenvironment
Boudová, Jana ; Sakala, Jakub (advisor) ; Ovčaří, Pavla (referee)
In the Most Basin, there is a rich variety of plant macrofossils, whose findings are described for the first time already in the 19th century. The presented thesis is focused on conifer wood preserved as xylitic stumps in situ. The samples come from the so-called "stumpy horizont No. 31" situated in the roof of the main lignite seam in the Bílina Mine. A detailed xylotomical study with scanning electron microscopy allows their assignment to the Cupressaceae s.l., to the morphospecies Glyptostroboxylon rudolphii and Taxodioxylon gypsaceum.
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Geomorphological position of coarse clastic deposits of the Lower Miocene in wider area of the Bohutický les upland in the South Moravia and their relation to neotectonic landscape evolution
Roštínský, Pavel
The contribution deals with geomorphological aspects of the Lower Miocene gravel formations in the area of Bohutický les upland in contact zone between the Bohemian Massif (built up of solid basement rocks) and basin of the Carpathian Foredeep (filled with weakly consolidated Lower Miocene clastic sediments). In the top part and slopes of the upland, numerous denudational relicts of formerly more extended sedimentary covers are situated, originated due to differential neotectonic movements in the area during syn- and postsedimentary periods. Coarse fraction is commonly preserved which were the least prone to surface destruction. During detailed mapping, three main lithological components of gravels were distinguished, their areal distribution and relations to solid-rock forms of present-day topography were studied and their possible genetic processes were outlined. The acquired information, added with borehole data, were related to landscape evolution of the wider South Moravia area.
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