Figure F12. Miocene, Pliocene, and Pleistocene chronostratigraphic units correlated with planktonic foraminifer and calcareous nannofossil zonations and with the geomagnetic polarity scale. Time scale is from Berggren et al. (1995a) with a tri-stage Pliocene based on Rio et al. (1990), and the reports of Cita (1996a, 1996b). Note that the FAD of G. truncatulinoides, which defines the base of N22, is globally diachronous and in areas other than the southwest Pacific occurs at 2.0 Ma (Dowsett, 1988).