Figure F12. Geomagnetic polarity time scale of Berggren et al. (1995), correlation of the Martini (1971) and Okada and Bukry (1980) calcareous nannofossil biostratigraphic zonations, and selected events used during Leg 178. FCO = first common occurrence. Age references: (1) Thierstein et al. (1977); (2) Raffi et al. (1993); (3) Lourens et al. (1996); (4) Tiedemann et al. (1994); (5) Raffi and Flores (1995); (6) Gartner (1990); (7) Backman and Raffi (1997); and (8) Berggren et al. (1995).