Lower Coevorden Member

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

Section of grey, calcareous, occasionally sandy claystones. Limestone beds occur frequently in the basal parts, but disappear upwards, where the clays are less calcareous ('t Hart 1969) . In type well Schoonebeek-197 some halite beds occur in the base.

Depositional setting

Marginal- to open-lacustrine setting with rare brackish influence. Fines settled from suspension. The carbonates (microcoquina shell beds) are interpreted as storm layers or periods of low sediment input (hardgrounds). Some fine sand was imported by small-scale fluvial/deltaic systems.

Definition of lower boundary

Clear claystone break, which is seen prominently on resistivity and sonic logs. In some salt-dome-related occurrences the Weiteveen Formation is absent, and the Coevorden Formation is in unconformable contact with the Altena Group or older deposits.

Definition of upper boundary

Fairly sharp increase in carbonate content. This generally coincides with the base of a funnel-shaped zone of increased resistivity-log readings. If the Middle Coevorden Member has been truncated, the Rijnland Group or younger deposits can overlay this member.

Thickness indication
Up to 140 m.
Geographical distribution
Regional correlation
UK: ?; GER: Bückeberg Formation (Wealden); BEL: -.
Depth (thickness) AH:
1126 - 1230 m (104 m)
Depth (thickness) AH:
1010 - 1046 m (36 m)
Depth (thickness) AH:
1679 - 1697 m (18 m)
Depth (thickness) AH:
1130 - 1174 m (44 m)
Depth (thickness) AH:
162 to 295 m (133 m)
Origin of name
Named after the town of Coevorden in the southeastern part of the Dutch province of Drente.
Previous name(s)
Lower Coevorden Clay member.
Reviewed by (date)
Sander Houben (2017).
‘t Hart, B.B. 1969. Die Oberjura- und Unterkreide-Sedimentation in den nördlichen und östlichen Niederlanden - Erdöl und Kohle, Erdgas, Petrochemie, 22, p. 253-261.
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]). Lower Coevorden Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from https://www.dinoloket.nl/en/stratigraphic-nomenclature/lower-coevorden-member.