Hannut Formation - Lithologies

Lithologies

The Hannut Formation can be about 100 meters thick in the Campine Basin and about 55 meters thick in the Mons Basin. In between these two basins the thickness varies between 40 and 20 meters. The formation is subdivided into five members:

• The Chercq Member, tuffite, clay and glauconite bearing sand layers. This member is most distinctively recognizable in the province of Hainaut;
• The Lincent Member, a locally lithified, predominantly clayey layer. It occurs in and around the Hesbaye region;
• The Halen Member, clayey silt and silty sand;
• The Waterschei Member, calcareous clay and silty clay. It occurs in the northeast of Belgium;
• The Grandglise Member, the upper glauconiferous sand. It is almost always present.