4.3.4 Petites Tailles Formation - PET
Author: Geukens, 1965, 1986, 1999.
Description: Whitish quartzitic sandstone, often breccia, compact bedded chloritic slate and conglomeratic sandstone with greenish shale pebbles.
Stratotype: Not yet defined; type area in the vicinity of Baraque de Fraiture and the hamlet Petites Tailles.
Area: Southern part of the Stavelot Massif.
Thickness: (>75 m).
Age: Without macrofossils and only long-ranging acritarchs present (Vanguestaine, unpublished); by its stratigraphical position supposedly between Mid or Late Ordovician (age of the underlying Bihain Fm) and the late Lochkovian (age of covering Fooz Fm, Hance et al., 1992). Geukens (1999) accepts for at least part of the formation an equivalence with the Colanhan Mbr of the Ottré Fm.