5.34 Lens Formation - LEN

Authors: Groessens et al., 1982; Paproth et al., 1983; Conil & Delcourt, 1989; Doremus & Hennebert, 1995a, 1995b; Hennebert, 1999.

Description: Generally pale, grey-blue to brownish grey, thick-bedded, fine- to coarse-grained, crinoidal and paleoechinoidal limestones. There is a rich macrofauna (Megachonetes, productids, Syringopora, gastropods). Dolomitic levels and chert occur at the base; oolitic levels in the upper part.

Stratotype: Old quarry and some exposures at Lens.

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

Thickness: 250 m in the type area.

Age: Moliniacian (Groessens et al., 1982).