Lithological description
Sequence of red-brown to variegated, silty, anhydritic claystones with intercalated anhydrite, rock salt and subordinate sandstones.
Depositional setting
Continental environment, alternation of fluvial, lacustrine and and evaporitic settings.
Definition of lower boundary
Marked by a shift in the acoustic velocity, which is considerable lower in the Keuper Formation. Along the basin fringe the interval comprising the Red Keuper Claystone and Dolomitic Keuper members may rest uncomformably on the Lower Muschelkalk Member. In a belt immediatly north of this fringe zone, these members may rest unconformably upon the lower Keuper members.
Definition of upper boundary
Base of the Sleen Formation, marks the Early Kimmerian II unconformity and is a promiment seismic marker. The Sleen Formation is easily recognizable on wire-line logs by its uniform thickness, relatively high gamma-ray and low acoustic-velocity readings.
Thickness indication
The thickness of the lower and middle Keuper displays a great variation. Areas of strong differential subsidence were situated in the Dutch Central Graben and the Ems Low, with over 1000 m, and in the northern P quadrant, with over 400 m. Undrilled halfgrabens, with thick Keuper sediment wedges, occur in the Central Graben.
Up to 589 m in well NSS-01-S1.
Geographical distribution
Regional correlation
UK: Triton Formation & Dudgeon Formation; GER: Keuper Group; BEL: Keuper Formation.
Age
Ladinian - early Rhaetian.
Origin of name
Name derived from the German stratigraphic nomenclature, where it is applied to the highest unit of the German Triassic.
References
NAM & RGD 1980. Stratigraphic nomenclature of The Netherlands. Verhandelingen van het Koninklijk Nederlands Geologisch Mijnbouwkundig Genootschap 32, 77 p.
Cite as
TNO-GDN ([YEAR]). Keuper Formation. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from https://www.dinoloket.nl/en/stratigraphic-nomenclature/keuper-formation.
