Figure F7. Combined calcareous nannofossil, planktonic foraminiferal, diatom and radiolarian biostratigraphic zonal schemes tied to the geomagnetic polarity time scale (Berggren et al., 1995b) and the New Zealand and European stages used during Leg 181 for the New Zealand region. The gray shaded area spanning the interval 55.5-54.6 Ma indicates the current range of differing usages of the Paleocene-Eocene boundary (after Berggren et al., 1995, p. 139).