The Warnantian Substage is about 8 to 12 Ma long and was defined as corresponding to the Cf6 Foraminifer Zone by Conil et al., 1977 (= MFZ13 to MFZ15 Zones of Devuyst & Hance (in Poty et al., in press). Its base is taken at the base of the Bonne River Formation (Fm); its top is defined by the base of the Namurian stage, but its upper part is almost completely missing in the Namur-Dinant Basin. The substage is covered by the RC7 and RC8 Coral Zones. It comprises the Bonne River and the Anhée Fms, which are mainly composed of shallowing-upward parasequences which were deposited by aggradation on the shelf, as suggested by their lateral regularity. It corresponds to the HST of the third-order sequence 8 (Thon-Samson Member of the Bonne River Fm) and to the third-order sequences 9 and 10 (Hance et al., 2001; Poty et al., 2002). The lower (MFZ13-MFZ14, RC7) and the upper Warnantian (MFZ15, RC8) can be correlated respectively with the British Asbian and Brigantian Substages.