5.2.1 Rocher de l’Uf Formation - RUF (old: Rv1)

Author: Beugnies, 1960

Description: Formation subdivided into two members. The unnamed lower member – (old: Rv1a) is made of an alternation of quartzite and slate beds up to 30 cm thick; beds seem often to be truncated; green at the base passing gradually into dark grey at the top (Beugnies, 1960; Belanger, 1998 ms). The Les Peureux Member (PEU, old: Rv1b) is a vein of black slate, not very thick, with slab or flag jointing; exploited for roofing slate.

Stratotype: Section in the crag of “le Rocher de l’Uf”, south of Fumay, Meuse valley.

Area: Rocroi Massif.

Thickness: 40 to 120 m; the Les Peureux Mbr is 3 to 5 m thick (Beugnies, 1960).

Age: The acritarchs from the upper part of the formation belong to the Zone 1, dated as Early Cambrian to Mid Cambrian (Vanguestaine, 1992).

Remarks: new name for unnamed formation in Beugnies, 1960.

(M. VANGUESTAINE)