Stiff bluish grey to brownish grey clay, slightly sandy to silty. Two or three lignite layers at the top. Locally, thin sand beds (very fine to fine).
Fluvial (flood basin, swamp).
Sharp contact with fluvial sand (Kieseloolite Formation, undifferentiated) and with shallow-marine sand (Oosterhout Formation).
Sharp contact with channel and bar sand and gravel (Tegelen Member, Waalre Formation) or with clayey eolian of local river sand (Stramproy Formation).