Original paper

Definition and use of the Bormidian stage. A critical review

Cita, Maria Bianca


The Bormidian stage was defined by PARETO (1865) in Southern Piedmont, to represent the lower part of the Miocene subsystem. The formations included in the Bormidian, however, are Oligocene in age as demonstrated by their fossil content. A stratotype section was designated at Spigno Monferrato by VERVLOET (1966), who also studied the foraminiferal content of the section. A discussion of the Spigno section, described by VERVLOET (1966) and by GELATI (1968) and of the Millesimo section, described by LORENZ (1964, 1969) and by BLOW & SMOUT (1968) leads to a criticism of the recent use of the term Bormidian and to some factual proposals.