AGGLUTINATED FORAMINIFERA OF WESTERN MEDITERRANEAN UPPER CRETACEOUS PELAGIC LIMESTONES (UMBRIAN APENNINES, ITALY, AND BETIC CORDILLERA, SOUTHERN SPAIN)

Agglutinated foraminifers of Upper Cretaceous pelagic limestones were studied from two road-sections near Gubbio (Italian Apennines) which are famous biostratigraphic and magnetostratigraphic standard sections for the Tethyan Upper Cretaceous, and from a section near Ronda (Penibetic Zone, southern Spain). A study of the stratigraphic distribution of these forms from the Turonian to Lower Paleocene led to the following results: 1) a lower part of the sequence is almost devoid of agglutinants. A few samples contain indeterminable "tubes' and Ammodiscus-Glomospira morphotypes. Radiolarians and silicified planktonic foraminifera occur frequently in the HCl residues; 2) a characteristic assemblage of agglutinated foraminifera appears in the Coniacian and Santonian. This assemblage is delineated by Haplophragmium problematicum and Uvigerinammina jankoi, 3) a distinct change in the faunal composition is observed in the Lower Campanian, 4) the K/T-boundary does not show an important taxonomic turnover in agglutinated foraminifers, but a sudden decrease in abundance and drastic quantitative change in the composition of the assemblages was detected in the Gubbio sections. -from Author