4.1.1 Hour Formation - HUR (old: Dva)
Author: after Geukens, 1999.
Description: Thick beds of light coloured to light greenish quartzite and green slate. The white sandstone is locally altered into a reddened sandstone.
Stratotype: outcrop in the Rocher de Hourt along the road N28 between Trois-Ponts and Vielsalm.
Area: In two anticlinal structures (Grand-Halleux and Ligneuville) in the southern part of the Stavelot Massif.
Thickness: >150 m.
Age: Due to the absence of macrofossils and acritarchs in the formation, a possible Neoproterozoic to Early Cambrian age is tentatively proposed (Mortelmans, 1977; Vanguestaine, 1992).