Oligocene diatom biostratigraphy for the Labrador Sea

The Oligocene diatom assemblage observed in samples from Hole 647A consists of a mixture of species characteristic of the low latitudes, the high southern latitudes, and the Norwegian-Greenland Sea. This diverse and well-preserved diatom assemblage allows a diatom stratigraphy to be established for the Labrador Sea and to be correlated with previously established diatom zonations. Changes in the composition of the diatom assemblage from warm-temperate to temperate species suggest a change in oceanographic conditions in the Labrador Sea during the early Oligocene.