3.1.5 Basse-aux-Canes Formation - BCN

Authors: Michot, 1934, 1954; Martin, 1969a; Delcambre & Pingot, in press c.

Description: Greenish grey or dark grey silty shale, often sandy siltstones, with irregular jointing. White mica often present. The siltstones weather with dark or rusty patches of iron and manganese oxides, described as a characteristic shining blue colour on freshly broken surface. No sandstone beds observed. The formation overlays the Sart-Bernard Fm.

Stratotype: not defined yet; in the southern part of the Puagne area, south-east of Sart-Eustache.

Area: Puagne-Sart-Eustache area, in the southern structural unit of the western part of the Condroz inlier.

Thickness: 100 to 150 m.

Age: Without fossils, tentatively estimated as Llanvirn or early Caradoc, Mid or Late Ordovician.

Remarks: Synonyms: the "unfossiliferous Basse-aux-Canes shale unit" which was considered as a part of the Vitrival-Bruyère Fm (Michot, 1934, 1954; Martin, 1969a). The unit resembles slightly the Vitrival-Bruyère Fm, but has no sandstone beds; it is possibly a lateral facies change of (a part of) that formation.

(B. DELCAMBRE and J. L. Pingot)