Code
SK
Status
Formal (NAM & RGD 1980). The SK-Group, SG-Group and SL-Group can be taken together as Upper Jurassic Supergroup (code S).
Lithological description
Group of formations with a predominantly clayey lithology, but also including limestones and evaporites in the lower part. Sands and conglomerates are restricted to the basin fringe.
Depositional setting
Fresh- to brackish-water lacustrine basin with intermittent marine and hypersaline periods. Hypersaline sediments dominate the Weiteveen Formation.
Definition of lower boundary
Unconformably on the Altena Group (or older sediments).
Definition of upper boundary
Unconformably overlain by the (sands or clays of the) Rijnland Group.
Thickness indication
100 - 250 m (up to 600 m in SE Drente).
Geographical distribution
Regional correlation
UK: ?; GER: ?; BEL: -.
Age
middle Kimmeridgian-Berriasian / early Valanginian.
Holostratotype
Depth (thickness) AH:
944 - 1590 m (646 m)
Parastratotype
Well:
Depth (thickness) AH:
994 - 1196 m (202 m)
Parastratotype
Depth (thickness) AH:
1644 - 1718 m (74 m)
Parastratotype
Well:
Depth (thickness) AH:
1109.5 - 1344 m (234.5 m)
Parastratotype
Well:
Depth (thickness) AH:
114 - 588 m (474 m)
Origin of name
Named after the German area of Niedersachsen (= Lower Saxony).
Previous name(s)
None.
Reviewed by (date)
Sander Houben (2017).
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]). Niedersachsen Group. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://acc.dinoloket.nl/en/stratigraphic-nomenclature/niedersachsen-group.