New hardgrounds in the Upper Cretaceous sediments at Čenkov (central Bohemia)


Jiří Žítt, Čestmír Nekovařík, Pavel Svoboda

Geoscience Research Reports 36, 2003 (GRR for 2002), pages 50–51
Map sheets: Mělník (12-22)

Full text (PDF, 0.95 MB)



Remarkable hardgrounds in bioclastic limestones forming a part of the Late Cretaceous sedimentary fill of a rocky bottom depression were recently discovered in the Čenkov quarry near Kralupy nad Vltavou (central Bohemia). Three closely spaced hardgrounds are developed in about the 15-40 topmost centimetres of the rock. Effects of corrosion, bioerosion (by boring bivalves), mineralization (mainly phosphatization), and encrustation (by epifauna) are well developed. The hardgrounds are of late Cenomanian age, but the uppermost (youngest) of them went through a period of partial destruction at the onset of the early Turonian marly sedimentation.