3.1.3 Sart-Bernard Formation - SN

Authors: Maillieux, 1939; Martin, 1969a; Servais & Maletz, 1992.

Description: Micaceous and sandy shale (Michot, 1957).

Stratotype: In the railway section north-west of the village Sart-Bernard, between km 73.1 and 73.3 (Martin, 1969; Servais & Maletz, 1992).

Area: Condroz inlier.

Thickness: not estimated yet.

Age: The restudied graptolite assemblage points to a Didymograptus bifidus biozone, Llanvirn (Bulman, 1950); this is not accepted by Servais and Maletz (1992) who follow the definition of Maillieux (1939) and include in the unit strata containing a macrofauna of several fossil groups of an ex-Llandeilo age.

Remarks: Synonym: Schistes de Sart-Bernard; Assise de Sart-Bernard.

(J. VERNIERS)