Lower Keuper Claystone Member

Formal (NAM & RGD 1980).
Lithological description

Reddish and dark-coloured claystones, alternating with thin layers of dolomite and fine-grained sandstone. Some coaly material occurs in the lower part of this member (Geluk, 2005); this is probably carbonized plant matter. The lower part is characterised by greyish colours, in the upper part red or red-brown colours predominate. The anhydrite content gradually increases towards the top.

Depositional setting

Fluvial floodplain.

Definition of lower boundary

Not yet defined.

Definition of upper boundary

Not yet defined.

Thickness indication
The greatest thickness, up to 200 m, occurs in the southern part of the Dutch Central Graben. In other areas, the thickness of the member is typically between 40 and 80 m.
Geographical distribution
Regional correlation
UK: Dudgeon Formation; GER: Erfurt Formation (Lettenkeuper); BEL: Lower Keuper Claystone Member.
Depth (thickness) AH:
3247 - 3368 m (121 m)
Depth (thickness) AH:
1738 - 1810 m (72 m)
Depth (thickness) AH:
1670 - 1740 m (70 m)
Origin of name
Previous name(s)
Reviewed by (date)
Johan ten Veen (2017).
Geluk, M.C. 2005. Stratigraphy and tectonics of Permo-Triassic basins in the Netherlands and surrounding areas. PhD Thesis, Utrecht University, 171 p.
NAM & RGD 1980. Stratigraphic nomenclature of The Netherlands. Verhandelingen van het Koninklijk Nederlands Geologisch Mijnbouwkundig Genootschap 32, 77 p.
Cite as
TNO-GDN ([YEAR]). Lower Keuper Claystone 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-keuper-claystone-member.