Succesion climatique et limite stratigraphique Crétacé-Tertiaire dans le N.E. de l'Espagne

The conclusions of spore and pollen assemblages studies yielded by the uppermost Cretaceous sections studied in the NE sector of Iberian Peninsula, are presented. Some climatic variations during the Maastrichtian- Ilerdian time span which can be occurred and are suggested by the data of the studied outcrops in the eastern and central pyreneean sectors. These variations are more or less independent of the chronostratigraphic boundary between the Cretaceous and the Lower Tertiary. Finally we consider that the present knowledge of paleofloristic data permits only a good qualitative aproximation to the Mesozoic/Tertiary boundary in non-marine levels.