Cenozoic benthic bathyal foraminifers of DSDP Site 548 (North Atlantic)

Benthic foraminifers from the size fraction greater than 63m were studied in 54 samples from the late Paleocene-Quatemary sequence of DSDP Site 548. In total 362 taxa were identified, 103 of which were considered as the most representative. Clustering of the samples on the basis of these foraminifers enabled recognition of six assemblage zones. The most important faunal break took place at the Eocene/Oligocene boundary. Thirty-four taxa appeared to be long ranging, being recorded from the Paleocene/Eocene through the Pliocene/Quaternary; the most abundant of these was Cassidulina subglobosa subglobosa. Absolute foraminiferal abundance was highest in the Oligocene. Relationships between water masses and marker species in Site 548 are in disgreement with results of most previous authors. The biostratigraphic zonation based on benthic foraminifers proposed by Berggren and Miller (1989) was not applicable to the site under study; not only were there very few foraminifers in common in two species lists, but also the few shared ones showed mostly dissimilar stratigraphic distribution.