CRETACEOUS/TERTIARY BOUNDARY IN THE CARPATHIAN TYPE UPPER

The present study of the Kladorub Formation, which is a part of the “Carpathian type Upper Cretaceous”, revealed a new K/T boundary interval section in Bulgaria. The studied interval comprises the boundary nannofossil zones of the Cretaceous and Paleocene- Micula prinsii and Biantholithus sparsus. Between these boundary zones, a 4 cm dark layer was established, marking the great change in the calcareous nannoplankton. The lithological analyses of the boundary interval between – 2.75 m to +4.00 m showed that this part of the section is represented mainly by siltstones and minor limestones and marls