Sequence of brownish-grey, marly, rarely sandy, claystones with occasional limestone beds, notably in its basal part. The limestone beds consist of pelecypod (typically Neomiodon) and/or ostracod microcoquina laminae. Claystones are usually finely laminated. On salt-domes (e.g. well Exloo Odoorn-2) and basin fringe settings, limestone beds are common throughout the formation.
Fresh- to brackish-water lacustrine-basin to marginal-marine sub-basin (lagoon) setting. Fine clastics dominate the basinal areas, while carbonates (shell beds) prevail in the basin-fringe and isolated elevated areas (e.g. salt-domes). These end-members are separated by a wide belt of transitional facies. The true basinal development is only known in the Netherlands from type well Schoonebeek-197.
On top of the claystone-marl-evaporite succession of the Weiteveen Formation. In some halokinetically influenced settings the Weiteveen Formation can be absent. There the Coevorden immediately and unconformably overlies the Altena Group or older deposits. The contact with the Weiteveen Formation (Serpulite Member) is marked by a clear claystone break, which is seen prominently on resistivity and sonic logs.
Below the basal, generally glauconitic beds of the Rijnland Group.
