Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
New hardgrounds in the Upper Cretaceous sediments at Čenkov (central Bohemia)
AbstractRemarkable 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.