Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)

Research report on the palaeontological investigations of the Šárka Formation (Middle Ordovician, Llanvirnian Stage) at Osek, near Rokycany, Czech Republic

 

Jana Slavíčková, Petr Budil

Geoscience Research Reports 33, 2000 (GRR for 1999), pages 135–137
Map sheets: Plzeň (12-33)

Full text (PDF, 0.33 MB)

 

Abstract

An important artificial outcrop was studied in the neighbourhood of the village of Osek near Rokycany (western Bohemia), near Barrande's classical locality "Wosek". A very rich faunal association, consisting of trilobites, brachiopods, bivalves, graptolites, dendroids, hyolitids and echinoderms was found in the dark grey clay shales and siliceous nodules of the Šárka Formation (Middle Ordovician, Llanvirnian Stage). Its character is typical for the middle part (Corymbograptus retroflexus Zone) of this formation, but some species found belong to the rare ones. Faunal remains often accumulate into sharply limited linear structures. As a hypothesis for the origin of these structures is submitted an accumulation due to wave or current activity. On the contrary, the findings of complete bivalve shells, complete trilobite exoskeletons and exuviae in the moulting positions suggest at least partial autochthonous or paraautochthonous origin for this faunal association.