Code
ATWDL
Status
Formal (NAM & RGD 1980).
Lithologische beschrijving
Grey, occasionally silty, claystones often containing characteristic clay-ironstone concretions and/or iron ooliths.
Afzettingsmilieu
Open marine.
Definitie ondergrens
Upon the bituminous claystones of the Posidonia Shale Formation.
Definitie bovengrens
First of the more calcareous, silty to sandy beds of the overlying Middle Werkendam Member.
Dikte indicatie
Up to 750 m (K14-FA-106).
Geografische verbreiding
Regionale correlatie
UK: West Sole Group; GER: Dogger Group; BEL: -.
Ouderdom
Toarcian - early Bajocian.
Holostratotype
Well:
Depth (thickness) AH:
2007 - 2205 m (198 m)
Oorsprong naam
None.
Vorige benaming(en)
None.
Gereviewed door (datum)
Sander Houben (2017).
Referenties
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 Werkendam 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-werkendam-member.