Latest Albian-earliest Turonian deep-water agglutinated foraminifera in the Bottaccione section (Gubbio, Italy) - Biostratigraphic and palaeoecologic implications.

Using semi-quantitative methods, the distribution of deep-water agglutinated foraminifera (DW AF) was analyzed within Latest Albian-earliest Turonian pelagic limestones famous Bottaccione standard section. The characteristic bathyal communities include forms purely "flysch-lype" assemblages and elements which are typical Upper Cretaceous abyssal environments North Atlantic. Well-established planktonic foraminiferal calcareous nannofossil zonations allowed to directly gauge stratigraphic ranges DW AF, contributing a better chronostratigraphic calibration zonation. Differences in sorne biostratigraphic marker species were observed. morphogroups enabled us interpret levels oxygenation organic input. effects Cenomanian-Turonian boundary event (here represented by ichtyolithic-bituminous-radiolaritic Livello Bonarelli) on AF explored detail. A major faunal change consisting marked decrease density richness recognized middle Rotalipora cushmani Zone coinciding with sedimentary regimes related extensive oxygen depletion sea bottom.&nbsp