Alternating claystones, siltstones, sandstones and some minor coal. The siltstones and claystones are generally grey or variegated and become increasingly reddish-mottled towards the south in the L blocks. Siderite spherulites and concretions are common. Several intervals of dark-grey to black silty, carbonaceous, fossiliferous claystone with intercalated calcareous beds can be encountered in the formation.
Non-marine (coastal) delta plain to lagoonal deposits.
Unconformably on the marine claystones and carbonates of the Altena Group or on older Triassic or Permian units.
Normally conformably overlain by the Skylge Formation. The Rijnland Group or the Scruff Greensand Formation occasionally rest unconformably on this formation if a prominent Late Kimmerian II unconformity is developed.