Code
NUNAWAZU
Status
Formal (Weerts 2003).
Lithological description
Greyish brown clay and fine sand, calcareous. Abundant marine shells at base. In northern reach and along margins, more greyish white sand.
Depositional setting
Brackish to saline tidal inland sea (clay) and fringing coast (sand).
Definition of lower boundary
At base, fine sand with abundant marine shells. Sharp contact with brackish lagoonal clay (Almere Bed, Walcheren Member, Naaldwijk Formation), peat (Hollandveen Member, Nieuwkoop Formation), periglacial sand (Boxtel Formation) or till (Gieten Member, Drente Formation).
Definition of upper boundary
Commonly, sharp contact with lacustrine clay (IJsselmeer Bed, Walcheren Member, Naaldwijk Formation). Elsewhere, exposed at the surface or on the lake bed.
Thickness indication
Up to about 3 m.
Geographical distribution
Zuiderzee, an inland extension of the North Sea that existed in the central Netherlands from the Late Middle Ages until its closure in 1932.
Regional correlation
North Sea: not present; UK: not present; GER: not present; BEL: not present.
Age
Holocene (Meghalayan, Late Medieval to pre-1932 AD).
Type section
Well:
Not yet determined.
Depth (thickness) AH:
Not yet determined.
Origin of name
Late-Medieval to 20th-century inland sea northeast of Amsterdam.
Previous name(s)
Zuiderzee deposit (Westland Formation).
Reviewed by (date)
Wim Dubelaar (2018), Sytze van Heteren (2019).
References
Weerts, H.J.T. 2003. Beschrijving lithostratigrafische eenheid. Nederlands Instituut voor Toegepaste Geowetenschappen TNO. Utrecht.
Cite as
TNO-GDN ([YEAR]). Zuiderzee Bed. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from https://www.dinoloket.nl/en/stratigraphic-nomenclature/zuiderzee-bed.