EARLY DANIAN BENTHIC FORAMINIFERAL COMMUNITY STRUCTURES, GEULHEMMERBERG, SE NETHERLANDS

Benthic foraminiferal assemblages from eight clay-layers within a rela tively thick section of the lowermost Paleocene (planktonic foraminife ra PO Zone) at the Geulhemmerberg, SE Netherlands, were examined for c hanges in abundance and species composition. The lower clay layers (A to D) are characterized by peculiar benthic foraminiferal assemblages with high numbers of small spiral forms which resemble modern epifauna l phytodetritus-feeding communities, that are well adapted to a food l imited environment in which much of the nutrient input is seasonally o r erratically pulsed. Another distinct assemblage with high numbers of small, infaunal morphotypes such as Tappanina selmensis, Reussella ex gr. europaea, buliminids and bolivinids characterizes the upper part of the succession (clay layers E and F). This assemblage exhibits stri king similarities to modern assemblages in areas with enhanced organic -matter export flux rates resulting in increased food supply for benth ic organisms and slightly dysaerobic conditions at the sea floor. The occurrence of these 'high-productivity' benthic foraminiferal assembla ges coincides with a marked increase in Thoracosphaera calcareous dino flagellate cysts and may indicate an important phase in the recovery o f the marine ecosystem after the collapse of the food web at the Creta ceous/Tertiary boundary.