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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Hlavonožci a biostratigrafie jurských sedimentárních celků severních Čech / Cephalopods and biostratigraphy of North Bohemian Jurassic sediments

Hrbek, Jan January 2011 (has links)
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
2

Nautiloidea svrchnokřídových epikontinentálních moří Evropy / Nautiloidea of Upper Cretaceous epicontinental seas in Europe

Frank, Jiří January 2014 (has links)
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...
3

Geneze a paleogeografický význam proplástků hlavní hnědouhelné sloje mostecké pánve / Genesis and paleogeographic significance of the clastic bands in the main coal of the Most Basin

Novotný, Tomáš January 2013 (has links)
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...
4

Vybraní hlavonožci (Cephalopoda) ordoviku pražské pánve a Baltiky(Estonsko a Švédsko): taxonomie, paleobiogeografie a paleoekologie / Selected cephalopods from the Ordovician of the Prague Basin (Bohemia) and Baltica (Estonia and Sweden): taxonomy, paleobiogeography and paleoecology

Aubrechtová, Martina January 2018 (has links)
This dissertation thesis is a summary of five studies published in peer- reviewed, impacted scientific journals. All of the publications are taxonomic revisions of previously unknown or little known collections of fossil cephalopods from the Early Paleozoic strata of Bohemia, Estonia and Sweden. Paleogeogra- phical and stratigraphical distributions of the respective taxa were summarized, refined and compared with contemporary fossil assemblages known from other regions. Implications on the paleoecology of the cephalopods and original envi- ronmental conditions were made. The text of the thesis is divided into three main parts. In the first part, the morphology of cephalopods is explained, stressing out the most important diagnostic characters used for their descriptions. The current systematics of the Cephalopoda is overviewed and the main cephalopod groups during the Ordovician are briefly introduced. The second part of the thesis describes the geological development and settings of the regions, from which the studied fossil cephalopods originate. The third and final part of the thesis provides a discussion and interpretation of the results of the published studies in the context of the previously published research. The genus Bactroceras Holm, 1898 and some members of the order Litui- tida were studied...
5

Belemniti spodní křídy (a hraničního intervalu hranice J/K) oblasti severozápadní Tethydy, biostratigrafie, paleobiogeografie a paleoekologie / Lower Cretaceous belemnites (including J/K boundary interval) in the NW Tethys, biostratigraphy, palaeobiogeography and palaeoecology

Vaňková, Lucie January 2021 (has links)
This thesis deals with the belemnite fauna from the Outer Western Carpathians Klippen, its systematic classification, stratigraphical and palaeogeographical evaluation. The palaeontological/palaeobiological approach, together with isotope analyses, including of carbon and oxygen stable isotopes and of strontium isotopes, enabled an integrated investigation of the palaeoecological conditions during the Jurassic/Cretaceous (J/K) boundary interval and the Early Cretaceous age. The Tethyan belemnites are not intensively studied in detail in the J/K interval, as they occur rather rarely in the sections, and/or sedimentary conditions were not suitable for their preservation. Therefore, belemnites are described only from a few sites in the Mediterranean Province. On the basis of recent research, the stratigraphic range of several species previously considered to be from the Tithonian age was extended to the earliest Cretaceous. By contrast, the Lower Cretaceous belemnites (since the late Berriasian) are more abundant. In the classical areas of the Tethyan Realm, it is possible to study the Lower Cretaceous belemnites in great detail and, according to their higher abundance, to determine an individual assemblage corresponding to stratigraphical intervals. Their occurrence is also an important basement for...

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