The base of the Bathonian is at the first appearance of ammonite species Parkinsonia (Gonolkites) convergens in the stratigraphic column.
The global reference profile for the base of the Bathonian (a GSSP) was ratified as Ravin du Bès, Bas-Auran area, Alpes de Haute Provence, France in 2009.
In the north and northeast, Russia, etc., clays, sandstones and ferruginous oolites prevail, some of the last being exploited for iron.
; in Africa, Algeria, Tanzania, Madagascar and near the Cape of Good Hope (Enon Beds); in India, Rajputana and Gulf of Kutch, and in South America.
[5] The well-known Caen stone of Normandy and "Hauptrogenstein" of Swabia, as well as the "Eisenkalk" of northwest Germany, and "Klaus-Schichten" of the Austrian Alps, are of Bathonian age.