In the southern part of the province of Noord-Brabant and in Limburg (basin fringe), the formation consists of fine-grained (105-150 µm), dark green-grey, glauconitic sand at the base, followed by light-grey marl and dark green-grey clay, progressively getting more marly and sandy upwards and in turn overlain by sandy clay with fine-grained (105-210 µm) sandy intercalations. Locally, in the north of the Province of Limburg, variegated clay and minor sand occur. Further north (more distally), the formation consists exclusively of grey to greenish grey clay with local marl intercalations (particularly in the basal part).
Initially transgressive, shallow-marine, locally lagoonal. Later followed by open-marine conditions. The maximum water depth may have reached several hundred meters. The upper part of the unit consists of regressive sands, probably related to NW-SE oriented prograding deltaic lobes, which locally has led to brackish conditions.
Unconformably overlies the chalk of the Houthem Formation or older units. The boundary is expressed as a sharp lithologic and log break.
Usually the Oosteind or the De Wijk members of the Dongen Formation overlie the Liessel Member of the Landen Formation with a sharp contact seperating them. In the southern Netherlands, where sands are intercalated with the Oosteind Member in the upper part of the formation, the boundary is less evident and biostratigraphical support is needed. In particular SE of the Tilburg-Den Bosch area. Where the Dongen Formation is absent, the current succession is covered unconformably by sandy deposits of the Tongeren Formation or the Rupel Formation.
