5.31 Basècle Formation - BAS

Authors: Dupont, in De Koninck, 1878; Bouckaert et al., 1961; Groessens et al., 1982; Paproth et al., 1983; Doremus & Hennebert, 1995a; Hennebert, 1999.

Description: Dark grey to black, fine-grained, sometimes argillaceous, limestones with argillaceous layers. Cherty at the base. The macrofauna is poor. Several lithostratigraphic units can be recognized within the formation. One of them, the Basècle Breccia Mbr – BBA (Groessens et al., 1982; Paproth et al., 1983), is composed of limestone breccia. In the middle part of the formation, two levels of black, very regular bedded, homogeneous micritic limestone occur ("marbre noir de Basècles").

Stratotype: Old quarries in the Basècles - Quevaucamps area. Basècle Mbr: Km 65.6 – 65.8 in the railway cutting between Basècle and Blaton.

Area: Western HSA, at least from Péruwelz to Fleurus.

Thickness: About 250 m in the type area.

Age: Moliniacian, Cf4a?, Cf4b, gForaminifer Subzones (Groessens et al., 1982).