1.2.11. Chooz Formation - CHO
Authors: Gosselet, 1868; Godefroid & Stainier, 1988, 1994b.
Description: Detrital formation essentially characterized by its red or mottled colours. At Vireux, two subunits are distinguished:
· a lower unit (±50 m), which contain argillaceous sandstones or quartzitic sandstones occurring as thick masses separated by red and green, rarely grey, shales and siltstones;
· an upper unit (270-280 m), which is mainly made up of red and green shales and siltstones with intercalations of red or green sandstone lenses or beds which may reach 10-14 m thick.
East of Hampteau, the top of the Chooz Fm is situated at the bottom of the first gravelly or conglomeratic bed of the Hampteau Fm and not at the last red bed as it is the case to the west.
Stratotype: For the lower limit, Vireux (France), Mont Vireux quarry; for the upper limit, Vireux-Mazée road, W of the crossing with the Givet road.
Area: S and SE flanks of the Dinant Synclinorium.
Thickness: 320-330 m.
Age: Emsian.