Formal (NAM & RGD 1980).
A grey, homogeneous, somewhat marly claystone, exhibiting a uniform, low acoustic-velocity and resistivity response on wire-line logs.
Definition of lower boundary
Conformably upon the more calcareous Middle Werkendam Member.
Definition of upper boundary
In complete successions it is covered by the Brabant Formation. The basal member of the Brabant Formation displays an upward increase in limestone and sandstone content, reflected by a clear funnel shape on most wire-line logs (lower GR, higher sonic-velocity and resistivity readings). The base of the Brabant Formation has been placed at the base of the first clean limestone bed, marked by a sharp log peak.
100 - 300 m.
UK: West Sole Group; GER: Dogger Group; BEL: -.
Bajocian to earliest Bathonian.
Origin of name
Reviewed by (date)
Sander Houben (2017).
NAM & RGD 1980. Stratigraphic nomenclature of The Netherlands. Verhandelingen van het Koninklijk Nederlands Geologisch Mijnbouwkundig Genootschap 32, 77 p.
TNO-GDN ([YEAR]). Upper 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/upper-werkendam-member.