The Callovian and Oxfordian of the Boulonnais area in northern France: new biostratigraphic data

Abstract

New exposures north of Marquise (Boulonnais, France) of “Montaubert Clays” (Upper Callovian) and “Coquillot Clays” (Lower Oxfordian) allowed to describe precisely: (i) detailed lithological succession of these formations; and for the first time: (ii) succession of ammonite faunas; (iii) succession of biohorizons. These outstanding sections indicate that all deposits from the Late CalIovian to the Lower Oxfordian (Mariae Zone) of Western Europe can now be correlated at the horizon scale.