Benthic foraminifera of the Baffin Bay and Labrador Sea

Above reflector R3, a coarse agglutinated assemblage containing more diversified calcareous benthic foraminifers was found that displays affinity to assemblages in the Norwegian-Greenland Sea. The faunal turnover near reflector R3 was interpreted as reflecting the onset (or renewal) of significant Denmark Straits Overflow Water at Site 646 at ~7.5 Ma, Agglutinated species disappear between reflector R2 and the base of the sediment drift, indicating a change in deep-water properties that occurred at ~ 4.7 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 --4.5 Ma. Drift formation ceased at ~2.5 Ma, concomitant with the appearance of ice-rafted sediments.

Pleistocene assemblages containing Stetsonia horvathi display affinity to deep assemblages in high-latitude ocean basins. Upper Pliocene and Pleistocene benthic assemblages at Site 647 contain N. umbonifera, which indicates a continued influence of corrosive deep water at the Gloria Drift.