The Cretaceous-Paleogene boundary and some events on this boundary

Present ideas on the position and radiological age of the C-P boundary are examined along with data on biotic events, changes of the ocean level, sedimentation conditions at the end of the Crataceous, the inversion of the geomagnetic field, volcanism, and tectonic movements on this boundary. Different lithological and geochemical peculiarities of the boundary horizon are discussed. It is suggested that the data on the character of events on the C-P boundary can only be explained on the basis of the impact model.