Rapid and profound changes in Earth surface environments and biota across the Frasnian-Famennian (Fr-Fa) boundary are well known and related to one of the five most severe mass extinction events in Earth history. Here, we present sedimentological, biostratigraphical, petrophysical (gamma-ray spectrometry, magnetic susceptibility) and geochemical (X-ray fluorescence) data from environmentally distinct sections in the Moravian Karst (Czech Republic) and compare them with the Steinbruch Schmidt section in the Kellerwald (Rheinisches Schiefergebirge, Germany). Both areas were located at the southern margin of Laurussia. The studied sections span the interval from the Lower or Upper rhenana to the Palmatolepis minuta minuta or younger conodont zones and the foraminiferal Eonodosaria evlanensis Zone and Eonodosaria evlanensis-Quasiendothyra communis Interzone including high resolution biozonation of the Fr-Fa boundary interval. In the Moravian Karst pure limestone facies of an inclined carbonate ramp reflect the worldwide trend in the widespread occurrence of calcimicrobes during upper Frasnian and lower Famennian. Geochemical and petrophysical data show a decrease in grain size of the siliciclastic supply and carbonate productivity in the Kellwasser Event intervals probably due to a deepening and correlate with maximum flooding surfaces and highstand system tracts in the Steinbruch Schmidt. Certain differences in some geochemical proxies between the Moravian Karst and Steinbruch Schmidt are due to lower carbonate dilution of the latter. Significant Zr, TiO 2 , Mn or Fe 2 O 3 enrichments may indicate the influence of volcanic sources in the studied Moravian Karst Fr-Fa sections.
The first tetrapodomorph spec i men from the Pa leo zoic se quences of the Moravian Karst (Moravo-Silesian Ba sin, Bo he mian Mas sif, Czech Re pub lic) is de scribed. The well-pre served, cosmine-cov ered lat eral extrascapular bone co mes from the Upper De vo nian (Famennian) hemipelagic Køtiny Lime stone of the Líšeò For ma tion. The af fin ity to the "osteolepiforms" is inferred from the cosmine his tol ogy and mor pho log i cal fea tures of the bone. As sign ment to the Megalichthyiformes seems most prob a ble. The as so ci ated fauna, e.g., clymenids, orthocone nautiloids, thin shelled bi valves, trilobites and cri noids, clearly dem on strate a ma rine en vi ron ment.
Úvod Globálně rozšířené střednofamenské annulata eventy bývají spojovány s krátkodobým interglaciálním vzestupem úrovně mořské hladiny, který přerušil celkové trendy regrese a postupné ochlazování klimatu (Sandberg et al. 2002, Joachimski et al. 2009). Vyznačují se polohami tmavě šedých až černých anoxických nebo hypoxických sedimentů, které často obsahují hojnou makrofaunu složenou zejména z ammonoidů, mlžů, ortokonních nautiloidů a ostrakodů (viz např. Walliser 1996). Annulata eventy stratigrafi cky spadají na bázi cephalopodové zóny Platyclymenia annulata (UD IV-A sensu Becker-House 2000). Korelace s konodontovou zonací byla delší dobu interpretována nejednotně. Předchozí autoři zařazovali annulata eventy do svrchní části zóny Palmatolepis rugosa trachytera (např. Walliser 1996, Raczka et al. 2010), kolem rozhraní zón Palmatolepis rugosa trachytera a Palmatolepis perlobata postera (House 2002) a do zóny spodní Palmatolepis perlobata postera (např. Korn-Ziegler 2002, Clausen-Korn 2008). Podle nejnovějších závěrů Hartenfelse (2011), který studoval detailně vzorkované profi ly z Německa (Rýnský masiv, saxothuringikum), Polska (Svatokřížské hory) a jv. Maroka, náleží spodní a svrchní annulata eventy do zóny svrchní Palmatolepis rugosa trachytera. Do téže zóny zařadil i nadložní polohy slínovce "Wagnerbank" a jeho ekvivalenty (např. "Annulata" limestone) (viz obr. 1). Na profi lech může být vyvinuta jedna nebo více poloh (zpravidla dvě) černých vápenců nebo břidlic annulata eventů (např.
Givetian limestones near Čelechovice contain rather abundant trilobites be longing to several species (for summary see Chlupáč 1992), whereas the Frasnian limestones of the Moravian Karst development are generally poor in trilobites and only a few rare specimens have been mentioned or described in the literature (
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