1.2.10. Vireux Formation - VIR

Authors: Gosselet, 1864; Godefroid & Stainier, 1988, 1994a.

 

Description: The Vireux Fm begins with blue grey quartzitic sandstones overlying the shales and siltstones of the Pesche Fm.  This formation is mainly made up of thick masses of blue grey or greenish quartzites and sandstones (eventually argillaceous) separated by dark grey or greenish shales and siltstones interbeds.  East of Olloy-sur-Viroin and W of Chooz, the shale beds increase.  Some sandstone layers contain shells or plants remains.  The top of the Vireux Fm is defined below the first red rocks of the Chooz Formation.

Two members are distinguished, respectively from bottom to top:

·       the Ecluse Member, in which the grey and blue grey colours are dominant and in which some layers contain fossils (corals, brachiopods, lamellibranchs, trilobites, crinoids);

·       the Ruisseau de Deluve Member, in which the argillaceous character of the rock is generally more pronounced, the greenish colour frequent and plant remains present in some levels.

The limit between the two members is defined at the top of the last bank containing macrofossils.

 

Stratotype: Vireux (France), Montigny quarry, left bank of the Meuse.

 

Area: S and SE sides of the Dinant Synclinorium, up to the surroundings of the Ourthe valley.

 

Thickness: > 80 m at Couvin, 120-120 m S of Chooz, 350 m in the Lesse valley, 400 m S of Grupont.

 

Age: Emsian.