2.2.5. Lomme Formation - LOM

Authors: Godefroid, 1991b.

 

Description: The formation is subdivided into two members. The Fond des Valennes Member, corresponding to the lower part of the formation, chiefly consists of sandy, occasionally micaceous or feldspathic, shales with intercalations of massif or micaceous sandstones. The overlaying Wamme Member consists of massif, micaceous sandstones in the lower part and alternating calcareous sandstones and shales in the upper part.

 

Statotype: Jemelle, section along the disused railway Jemelle-Rochefort, near km 2 and section in the Lhoist quarry, about 500m north-east of the village church.

 

Area: South-eastern flank of the Dinant Synclinorium between Tellin and the Xhoris Fault;? Couvin area.

 

Thickness: About 110m in the Jemelle area, thickness increasing eastward up to the Hotton area and then gradually decreasing up to the Xhoris area.

 

Age: Late Eifelian, kockelianus and ensensis conodont Zones (Godefroid, 1968; Bultynck, 1999; Bultynck et al. 2000).

 

Remarks: At Couvin a thin unit at the top of the Jemmelle Fm and about 15m thick, consisting of silty shales alternating with argillaceous, calcareous, micaceous siltstones may represent the Lomme Fm.