Ruinen Member KNNCE


Premise Definition extended after NAM and RGD (1980) . The lithological affix has been deleted. If the Ruinen Member cannot be distinguished from the Westerbork Member, the whole interval can informally be referred to as Schoonebeek mb. (KNNCS), which is not defined separately here.
Derivatio nominis Named after the village of Ruinen, in the province of Drente, in the north-eastern part of the Netherlands.
Type section Location map See figure (pdf)
  Well Westerbork-1 (pdf)
  Location N 52°46’08.0
E 06°36’54.1
  Depth 1121 to 1143 m
  Length 22 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 1544 to 1555 m
  Length 11 m along hole
  Reference .
Definition Thin sequence of fossiliferous (fish remains etc.), dark-grey, silty to pebbly, micaceous, locally coaly, calcareous claystones, generally topped by a thin silt- or sandstone bed (called ’Grenzsandstein’ in NAM and RGD (1980) , here included in the Westerbork Member). The sediments often are ferruginous, and dispersed iron oolites are encountered. The whole member displays an overall funnel shape on the SP-log, which is not visible very well on other logs.
Upper Boundary The upper contact, with the Westerbork Member, is unconform-able, consequently the Ruinen Member can be very thin or even completely missing. The contact with the Westerbork Member is best seen on an SP log (as a transition from funnel- to bell-shape). On GR logs it is barely visible, as a result of the glauconitic character of the marker sand-stone bed. Locally the member is covered unconformably by the Holland Formation
Lower Boundary The member conformably covers the Bentheim Sandstone Member of the Vlieland Sandstone Formation The transition is marked by a sharp increase in GR-log readings.
Distribution Restricted to the southern Dutch Lower Saxony Basin, i.e. southwestern Drente and eastern Overijssel. This member is not very widespread. Its distribution is related to the presence of the Gildehaus Member of the Vlieland Sandstone Formation, but also depends on the amount of erosion beneath the Westerbork Member and the Holland Formation. The main Vlieland Claystone Formation is a lateral equivalent to thenorth and east (basin centre). Some occurrences of Vlieland Sandstone Formation (Friesland Member) to the west (basin fringe) are laterally equivalent.
Age Mid- to Late Valanginian, as indicated by top occurrence of Ammovertella cellensis, Haplophragmium inconstans erectum.
Depositional Setting Palaeontological data and facies association suggest a lagoonal to open-marine deposition. It is generally seen as the basinal equivalent of coastal-barrier systems formed towards the basin-fringe. However, in Ruinen-1 lagoonal deposits have been encountered which were formed behind this prograding barrier system, judging from an absence of e.g. dinoflagellates.
Sequence Stratigraphy This member reflects the LZB 2.2 Maximum Flooding. The later parts of LZB 2.2, the full sequence LZB 2.3, up to the Early Transgressive tract of LZB 2.4 are represent-ed by a hiatus.
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].