Neogene benthic foraminifer biostratigraphy and deep-water history of Sites 645, 646, and 647, Baffin Bay and Labrador Sea

Benthic foraminifers were examined from Neogene sediments ODP Sites 645, 646, and 647 to determine their biostratigraphy and to place constraints on the paleoceanographic history of Baffin Bay, Eirik Ridge, and the Gloria Drift. At Site 645 in Baffin Bay, a Pleistocene Stetsonia assemblage is similar to the modern Baffin Bay assemblage, but an underlying Epistominella takayanagii assemblage has no modern analog. At Site 646 in the Labrador Sea, benthic faunal turnovers occur near important seismic horizons. A Miocene Nuttallides umbonifera assemblage similar to assemblages at other North Atlantic sites occurs below reflector R3. Above reflector R3, a coarse agglutinated assemblage containing more diversified calcareous benthic foraminiferas was found that displays affinity to assemblages in the Norwegian-Greenland Sea. Agglutinated species disappear between reflector R2 and the base of the sediment drift, indicating a change in deep-water properties that occurred at c4.7 Ma. This turnover ultimately may be linked to the reopening of the Mediterranean. The beginning of drift sedimentation at the Eirik Ridge is dated at c4.5 Ma. Drift formation ceased at c2.5 Ma, concomitant with the appearance of ice-rafted sediments. -from Authors