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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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Lower Turonian ammonites of the Bohemian Cretaceous Basin: taxonomic synopsis, stratigraphy and palaeoecology
Kohout, Ondřej ; Košťák, Martin (advisor) ; Ziegler, Václav (referee)
This thesis summarizes the findings of lower Turonian ammonites of the Bohemian Cretaceous Basin (BCB). It presents an overview of the most important taxonomic species and their brief morphology and paleoecology. Marginally, it describes sedimentary facies of the BCB which belongs to the lower Turonian ("Bílá Hora" Formation). Part is devoted to determining the stratotype between Cenomanian and Turonian, to the events that occurred during this period (CTBE, OAE II) and their impact on biocoenosis of early Turonian ammonites. This thesis tries to comprehend the importance of ammonites biostratigraphy to define the Lower Turonian and basic ammonites zones, which belongs to this period. Defining stratotype Cenomanian / Turonian has not yet been satisfactorily resolved and this work is the basis for further research and study. Key words: ammonite, Bohemian Cretaceous Basin, biostratigraphy, Turonian, paleoecology
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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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