Upper Werkendam Member

Code
ATWDU
Status
Formal (NAM & RGD 1980).
Lithological description

A grey, homogeneous, somewhat marly claystone, exhibiting a uniform, low acoustic-velocity and resistivity response on wire-line logs.

Depositional setting

Marine.

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.

Thickness indication
100 - 300 m.
Geographical distribution
Regional correlation
UK: West Sole Group; GER: Dogger Group; BEL: -.
Age
Bajocian to earliest Bathonian.
Holostratotype
Depth (thickness) AH:
1746 - 1953 m (207 m)
Origin of name
None.
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]). Upper Werkendam Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://www.dinoloket.nl/en/stratigraphic-nomenclature/upper-werkendam-member.