2.2.2. Eau Noire Formation - ENR
Authors: Bultynck & Godefroid, 1974; Bultynck, 1991b.
Description: The lower part consists essentially of greyish calcareous shales with bioclasts and a few nodules and argillaceous mostly nodular limestone beds. The upper part alternates between calcareous shales with bioclasts and crinoidal limestone beds. The macrofauna consists mainly of solitary rugose and tabulate corals.
Stratotype: Couvin (La Foulerie), section along the west banks of the Eau Noire river, about 100m north of the foot-bridge.
Area: Southern and south-eastern flank of the Dinant Synclinorium up to Hotton-Hampteau; from Villers-Ste-Gertrude on it becomes difficult to separate the Eau Noire Fm from the underlaying St-Joseph Formation.
Thickness: About 60m between Couvin and Olloy-sur-Viroin, farther to the east the thickness increases to a maximum of 160m in the Wellin-Halma area; east of this area the thickness decreases, 55m at Grupont, 45 at Jemelle and about 15m at Hampteau.
Age: Latest Emsian-earliest Eifelian. The base of the Eifelian, recognized by conodonts belonging to the partitus Zone, is 50m above the base of the formation in the Eau Noire section at Couvin (BULTYNCK et al., 2000).