Clay Deep Member

Formal (NAM & RGD 1980). Amended (Herngreen & Wong 1989; Van Adrichem Boogaert & Kouwe 1993; Munsterman et al. 2012).
Lithological description

Comprises (brownish-) grey to black claystones. The base is usually more silty. The claystones are generally rather bituminous, but locally less organic matter may be present.

Depositional setting

Shelf environment. Basin circulation stagnated which resulted in dysoxic to anoxic basin-floor conditions and in the deposition of bituminous claystones.

Definition of lower boundary

Unconformably on the undifferentiated Scruff Greensand Formation (block F03) or Kimmeridge Clay Formation. The bituminous claystones of the Clay Deep Member can be distinguished easily from the main Kimmeridge Clay Formation by their higher GR- and resistivity-log response. The contact with the Scruff Greensand Formation below is clear because of the change in lithology.

Definition of upper boundary

Coincides with the Berriasian-Valanginian boundary (Sequence 3 / Sequence 4 transition sensu Abbink et al. 2006). It is associated with the Late Kimmerian unconformity. Covered (sometimes virtually conformably) by the Rijnland Group (or the Chalk or Lower North Sea Group).

Thickness indication
Up to 100 m.
Geographical distribution
Regional correlation
UK: Humber Group; GER: ?; BEL: -.
Depth (thickness) AH:
2225 - 2315 m (90 m)
Depth (thickness) AH:
2265 - 2335 m (70 m)
Origin of name
Named after the Clay Deep, a sea-bottom depression situated at approximately N 55°, E 04° in the Netherlands offshore.
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.
Herngreen, G.F.W., De Boer, K.F., Romein, B.J., Lissenberg, Th., Wijker, N.C. 1983. Middle Callovian beds in the Achterhoek, eastern Netherlands. Mededelingen Rijks Geologische Dienst 37, 95-123.
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.
Abbink, O.A., Mijnlieff, H.F., Munsterman, D.K. & Verreussel, R.C.M.H. 2006. New stratigraphic insights in the ‘Late Jurassic’ of the Southern Central North Sea Graben and Terschelling Basin (Dutch Offshore) and related exploration potential. Netherlands Journal of Geosciences 85, 221-238.
Munsterman, D.K., Verreussel, R.M.C.H., Mijnlieff, H.F., Witmans, N., Kerstholt-Boegehold, S. & Abbink, O.A. 2012. Revision and update of the Callovian-Ryazanian Stratigraphic Nomenclature in the northern Dutch Offshore, i.e. Central Graben Subgroup and Scruff Group. Netherlands Journal of Geosciences-Geologie en Mijnbouw, 91 (4), 555-590.
Cite as
TNO-GDN ([YEAR]). Clay Deep Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from