Lamont-Doherty Geol. Obs., United States

Goban Spur in the northern Bay of Biscay, upper Eocene-lower Oligocene nannofossil chalks. The Eocene-Oligocene boundary as identified by nannofossils does not coincide with that recognized using planktonic foraminifers. No dramatic nannofloral or planktonic foraminiferal change occurred at the boundary. There was a gradual transition from warm-water to cool-water assemblages through the late Eocene, with more intense cooling indicated by low-diversity assemblages in lower Oligocene sediments. A major benthic foraminiferal faunal change occurred in the early late Eocene. No major benthic assemblage changes occurred at the Eocene-Oligocene boundary.--Modified journal abstract.