Thin sequence of fossiliferous, dark-grey, silty to pebbly, micaceous, locally coaly, calcareous claystones, generally topped by a thin silt- or sandstone bed. The sediments often are ferruginous, and dispersed iron oolites are encountered.
Lagoonal to open-marine deposition.
Definition of lower boundary
Conformably covers the Bentheim Sandstone Member of the Vlieland Sandstone Formation.
Definition of upper boundary
Unconformable with Westerbork Member, consequently the Ruinen Member can be very thin or even completely missing. Locally covered unconformably by the Holland Formation.
UK: Valhall Formation; GER: ~Minden-Braunschweig-Gruppe; BEL: -.
middle - late Valanginian.
Origin of name
Named after the village of Ruinen, in the province of Drenthe.
NAM & RGD 1980. Stratigraphic nomenclature of The Netherlands. Verhandelingen van het Koninklijk Nederlands Geologisch Mijnbouwkundig Genootschap 32, 77 p.
TNO-GDN ([YEAR]). Ruinen Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://www.dinoloket.nl/en/stratigraphic-nomenclature/ruinen-member.