5.4 Landelies Formation - LAN

Authors: de Dorlodot, 1895 (Calcaire de Landelies); Mamet et al., 1970; Paproth et al., 1983.

Description: The dominant facies comprises crinoidal packstones to rudstones with numerous rugose corals and brachiopods. A subdivision into three units can be recognized in many places: (1) a basal, metre-thick bed of crinoidal limestone, which abruptly overlies the argillaceous limestones and shales of the Pont d’Arcole Formation; (2) a succession of calcareous shale-limestone parasequences; and (3) thick-bedded crinoidal limestones.

The contact with the overlying Maurenne Formation is sharp.

Stratotype: Abandoned quarry on the western bank of the River Sambre, 1.5 km north of the church at Landelies (DSA).

Area: The formation outcrops widely in the CSA, DSA and ASA. The lower member of the Engihoul Dolomite Fm is its lateral equivalent in the NSA.

Thickness: 23 m in the stratotype, up to 85 m in the western part of the NSA, 10 m or less in the eastern part of the CSA (Vesdre area).

Age: Hastarian. Cf1a and bForaminifer Subzones; Siphonodella Conodont Zone; RC2 Rugose Coral Zone (Conil et al., 1991). The Landelies Fm corresponds to the HST of the third-order sequence 2 of Hance et al. (2001).