Coevorden Formation

Formal (NAM & RGD 1980). Amended (Van Adrichem Boogaert & Kouwe 1993).
Lithological description

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.

Depositional setting

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.

Definition of lower boundary

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.

Definition of upper boundary

Below the basal, generally glauconitic beds of the Rijnland Group.

Thickness indication
Up to 150 m.
Geographical distribution
Regional correlation
UK: ?; GER: Bückeberg Formation (Wealden); BEL: -.
Berriasian - earliest Valanginian.
Depth (thickness) AH:
944 - 1230 m (286 m)
Depth (thickness) AH:
994 - 1046 m (52 m)
Depth (thickness) AH:
1644 - 1697 m (53 m)
Depth (thickness) AH:
1109.5 - 1174 m (64.5 m)
Depth (thickness) AH:
114.2 - 295 m (180.8 m)
Origin of name
Named after the town of Coevorden in the southeastern part of the Dutch province of Drente.
Previous name(s)
Reviewed by (date)
Sander Houben (2017).
NAM & RGD 1980. Stratigraphic nomenclature of The Netherlands. Verhandelingen van het Koninklijk Nederlands Geologisch Mijnbouwkundig Genootschap 32, 77 p.
Van Adrichem Boogaert, H.A. & Kouwe, W.F.P. 1993. Stratigraphic nomenclature of The Netherlands; revision and update by RGD and NOGEPA, Section G, Upper Jurassic and Lower Cretaceous. Mededelingen Rijks Geologische Dienst, 50, 1-80..
Cite as
TNO-GDN ([YEAR]). Coevorden Formation. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from