Pliocene to Pleistocene planktonic foraminiferal datum levels in the North Pacific

These three sites have been correlated on the basis of planktonic foraminiferal events and major paleoclimatic/paleoceanographic intervals and tied to diatom, radiolarian, and nannofossil datum levels, and paleomagnetic and isotopic stratigraphy. Ten planktonic foraminiferal datum levels have been recognized within these Pliocene to Pleistocene sections; two of these are recognizable within the Pleistocene and eight within the Pliocene.

Six planktonic foraminiferal zones are proposed which combined with the foraminiferal datum levels provide a high resolution biostratigraphic correlation for the mid-latitudes of the North Pacific.