Rijswijk Member KNNSR


Premise Definition extended after NAM and RGD (1980) , originally Rijswijk Sandstone Member. The lithological affix has been deleted, since the member does not necessarily consist exclusively of sandstone.
Derivatio nominis Named after the village of Rijswijk in the province of Zuid-Holland.
Type section Location map See figure (pdf)
  Well De Lier-40 (pdf)
  Location N 51°58’57.7
E 04°13’23.3
  Depth 1928 to 1995 m
  Length 67 m along hole
  Reference NAM and RGD (1980)
Definition Light- to medium-grey sandstones with a very fine to medium and locally gravelly grain size; mica, lignitic matter and siderite concretions are common. Locally, lignitic claystone beds are present, especially near the base. Cored sections in the type area show high- and low-angle cross bedding and planparallel bedding. In blocks Q11-Q14 very fine- to fine-grained, bioturbated sandstones with considerable intercalations of claystones predominate.
Upper Boundary Both the lower and upper boundaries are well-defined at the base and top of the marine sandstone body..
Lower Boundary . The member conformably overlies the lower-coastal-plain to lagoonal deposits of the Rodenrijs Member (Nieuwerkerk Formation).
Distribution West Netherlands Basin and adjacent Q quadrant.
Age In the type area mid- to Late Hauterivian. Assemblages recorded are generally not rich in microplankton, but may be characterised by the presence of Subtilisphaera perlucida. Sporomorph assemblages are characterised by the presence of Concavisimisporites verrucosus and the absence of Valanginian types. In Q11-Q14, Late Valanginian to Early Hauterivian in age (similar to the youngest Helder Member, informal Logger Sandstone member), reflecting the gradual transgression coming from the north-northwest. The Rijn Member is a basinward equivalent to the north-northwest. For differentiation diagnostics, see under Rijn Member The uppermost Alblasserdam Member of the Nieuwerkerk Formation in the Rotterdam area is the terrestrial equivalent of the Rijswijk Member in its type area. The Delft and Rodenrijs Members of the Nieuwerkerk Formation are fluvial resp. lagoonal equivalents of the lower parts of the Rijswijk Member in the Q07 to Q14-area.
Depositional Setting The Rijswijk Member sands is comprised of coastal sands, deposited between the open-marine Rijn Member sands to the northwest and the terrestrial Nieuwerkerk Formation to the southeast. The majority of the sands in this member have been deposited as basal transgressive sands, which were intensely reworked by bioturbation, waves and storms, or as stacked relicts of prograding coastal-barrier systems. The transgressive sands in Q11-Q14 occurrences show an open- to restricted-marine affiliation.
Sequence Stratigraphy In the type area, this member represents the entire sequence LZB 3.1 and the Early Transgressive systems tract of LZB 3.2. Along the southern margin of its occurrence, it represents only the Transgressive tract of LZB 3.2. In the area of blocks Q14 to Q07 the sequences LZB 2.5 to 2.2 progressively become developed as Rijswijk Member In this area the uppermost meters of the member reflect the Transgressive systems tract of sequence LZB 3.1.
  Intercalated fine-grained intervals of regional continuity, as seen in the Q11-Q14 area, can informally be called Rijswijk Claystone beds (KNNCR), dividing the Rijswijk Member into an equally informal upper Rijswijk Sandstone beds (KNNSN, previously also informally called ’Noordwijk Sandstone’ by NAM) and lower Rijswijk Sandstone beds (KNNSR).
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].