Bentheim Claystone Member KNNCV


Premise Definition extended after NAM and RGD (1980) . For the sake of purity the lithological affix has been changed from ’Shale’ to ’Claystone’.
Derivatio nominis Named after the town of Bad Bentheim in Germany, in the area of Niedersachsen.
Type section Location map See figure (pdf)
  Well Westerbork-1 (pdf)
  Location N 52°46’08.0
E 06°36’54.1
  Depth 1176 to 1192 m
  Length 16 m along hole
  Reference NAM and RGD (1980)
Additional section Location map See figure (pdf)
  Well Sleen Dommerskanaal-1 (pdf)
  Location N 52°41’39.7
E 06°52’49.8
  Depth 1613 to 1616 m
  Length 3 m along hole
Definition Thin marly, silty to sandy claystone interval with marine fossils, intercalated between the Bentheim Sandstone Member above, and the non-marine Coevorden Claystone Formation below.
Upper Boundary The member is covered conformably by the Bentheim Sandstone Member of the Vlieland Sandstone Formation. The boundary is placed at the base of the massive sandstone.
Lower Boundary The member mildly unconformably covers the Coevorden Claystone Formation (Upper or Middle Member, e.g. Ruinen-1). The transition is marked by higher readings on the GR-log, and lower resistivity readings. Sonic-log patterns show a shift to quiet patterns and low velocities.
Distribution Dutch part of the Lower Saxony Basin: eastern parts of the provinces of Drente and Overijssel. Because of the definition, the distribution coincides with that of the Bentheim Sandstone Member. The main Vlieland Claystone Formation is a basinward lateral equivalent to the east, while the Vlieland Sandstone Formation (Friesland Member, Bentheim Sandstone Member) is an equivalent to the basin fringe, in the north and west. In Germany the equivalent claystone interval is called ’Platilenticeras Schichten’.
Age This member was formerly interpreted as ’middle’ Valanginian (a.o. NAM and RGD (1980) , after the old German name: ’toniges Mittel-Valendis’), but current views indicate an Early Valanginian age. Diagnostic fossil taxa are Trilobosporites bernissartensis, Ammovertella cellensis, Haplophragmium inconstans erectum.
Depositional Setting Palaeontological data and facies association suggest an open-marine deposition. It is seen as the basinal equivalent of coastal-barrier systems formed towards the basin-fringe.
Sequence Stratigraphy This member reflects the LZB 2.1 Maximum Flooding.
References See References Upper Jurassic/ Lower Cretaceous

Van Adrichem Boogaert, H.A. & Kouwe, W.F.P., 1993-1997. [Stratigraphic unit]. In: Stratigraphic Nomenclature of the Netherlands.
Retrieved [Datum] from [url].