Resumen de Planktic foraminiferal biostratigraphy and sedimentology of the Cretaceous-Tertiary boudary in the Sernikaki section (The Parnassus-Ghiona Zone, Central Greece)

Nikolaus Solakius, Fotini Pomoni Papaioannou, Nikolaos Marangoudakis

• Investigations on the lithology and on the planktic foraminiferal fauna included in the sedimentary strata of the Sernikaki section, the Parnassus-Ghiona Zone, revealed the presence of three lithological units in the section, viz. the foraminiferal limestone, the hardground horizon and the red marls of the flysch, aso that the section is of Late Maastrichtian-Paleocene age. The foraminiferal limestone which was deposited under calm marine conditions is found to belong to the Upper Maastrichtian Gansserina gansseri Zone. A break in the deposition extending from the end of the Maastrichtian, until the Early Paleocene (Morozovella pseudobulloides interval) is demonstrated. This break gave rise to the development of of a hardground bed on top of the foraminiferal limestone which because of the low rate of sedimentation of phosphatic-glauconitic and iron-oxide deposits, and the interruptions that followed, continued to developed as a gardground until the appearance of Planorotalites pseudomenardii (Bolli) in the Late Paleocene. At the end of the Paleocene the character of the deposition changed, the red marls of the flysch facies being deposited. This deposition of marls continued unaltered into the early part of the Eocene.