2.2.11. Fromelennes Formation - FRO

Authors: Maillieux, 1922; Errera, Mamet & Sartenaer, 1972; Coen-Aubert, 1991b.

 

Description: In an unpublished Ph. D. dissertation ERRERA (1976) subdivided the Fromelennes Fm into three members, in ascending order the Flohimont, Moulin Boreux and Fort Hulobiet Members. These subdivisions were subsequently adopted in several publications. The lowest part of the Flohimont Mbr consists of thin bedded argillaceous limestones with brachiopods. The major part of the member consists of alternating nodular shales and argillaceous limestones with a rich brachiopod fauna. The Moulin Boreux Mbr consists of alternating biostromal beds with domical and branched stromatoporoids and micritic, occasionally dolomitic limestones, sometimes finely laminated. The Fort Hulobiet Member is made up of platy limestones typically with bivalves and phaceloid colonial rugose corals in the upper part. In some sections the platy limestones are less developped and biostromal beds with globular and branched stromatoporoids occur.

 

Stratotype: Section along the local road D46 between Fromelennes and Flohimont (France), about 3km south-east of Givet completed by the nearby Cul de Houille quarry.

 

Area: Southern and south-eastern flank of the Dinant Synclinorium and Philippeville Massif. To the north the Fromelennes Fm passes into the Le Roux Fm.

 

Thickness:About 135m in the stratotype. The formation is 10 to 15m thicker to the east between Dion and Hotton. More to the north-east the thickness decreases. In the Philippeville Massif the thickness is about 80m.

 

Age: Middle to late Givetian. In the stratotype section the lowest part of the Flohimont Mbr is assigned to the rhenanus/varcus conodont Zone (= upper part of Lower varcus Zone) and the overlaying part to the ansatus Zone (= Middle varcus Zone). Not any conodont fauna was obtained from the Moulin Boreux Member. In Nismes and Wellin the Fort Hulobiet Mbr can be assigned to the Lower falsiovalis Zone (Bultynck, 1987; Bultynck et al., 2000).