Fourteens Claystone Member SLDBC


Premise Definition amended after NAM and RGD (1980) , as the Fourteens Clay Formation.
Derivatio nominis Named after the Broad Fourteens, an offshore shoal west of the Dutch province of Noord-Holland. NAM and RGD (1980)
Type section Location map See figure (pdf)
  Well K15-01 (pdf)
  Location N 53°13’28.2
E 03°53’47.6
  Depth 1833 to 2110 m
  Length 277 m along hole
  Reference NAM and RGD (1980)
Additional section Location map See figure (pdf)
  Well K18-Kotter-07A (pdf)
  Location N 53°04’56.1
E 03°57’56.8
  Depth 2571 to 2695 m
  Length 124 m along hole
  Reference 111 m TVD.
  Well Q01-03 (pdf)
  Location N 52°52’00.2
E 04°08’33.4
  Depth 1525 to 2122 m
  Length 597 m along hole
Definition Sequence of predominantly medium to dark greenish-grey, locally light grey or mottled red, silty, locally slightly calcareous claystones, with locally minor intercalated thin, fossiliferous limestones, siltstones, and rare nodular, calcitic or dolomitic anhydrite beds.
Upper Boundary In blocks Q01 and K15, where the Santpoort Member is not recognised, the Fourteens Claystone Member is conformably overlain by the sandy Bloemendaal Member. Otherwise, the top is represented by the conformable contact with sandier sediments of the Santpoort Member In Subhercynian/ Laramide-inverted basin structures an unconformable contact with the Chalk or Lower North Sea Group can be seen. Locally, however, the Neomiodon Claystone Member or Rijnland Group can unconformably overlie the Fourteens Claystone Member
Lower Boundary The base is formed by the conformable contact with more sandy sediments of the Aerdenhout Member, or the unconformable contact with the Altena Group (suggested only by seismic data).
Distribution Found in most of the Broad Fourteens Basin. The distribution virtually coincides with that of the Breeveertien Formation, except for areas of severe Late Kimmerian or Subhercynian/Laramide truncation.
Age Early Kimmeridgian to Portlandian, depending on the presence of other members (e.g. Santpoort Member). A low diversity, restricted marine, Early Kimmeridgian dinoflagellate association is often found (abundant Geiselodini-um paeminosum, Cribroperidinium granuligerum group, Amphorula metaelliptica). The marine character diminishes upwards, as sporomorphs (Classopollis spp., Gliscopollis spp.) become dominant. Dinoflagellates, however, remain present. Ostracod species typical of this member are Rhinocypris rasilis, R. jurassica, Bisulcocypris forbesi, B. dilatata, Cetacella armata, C. inermis, Cypridea valdensis praecursor, Fabanella polita ornata, Klieana alata and Damonella ellipsoidea. In areas where the Santpoort Member and Driehuis Member are not recognised, the Fourteens Clay-stone Member can contain Portlandian fossil associations, as described in sections 2.9.3 and 2.9.4.
Depositional Setting In contrast to the shallow-marine depositional setting mentioned by NAM and RGD (1980) , the Fourteens Claystone Member is currently interpreted as deposited in a predominantly terrestrial, lacustrine to restricted lagoonal, coastal-plain setting with intermittent brackish-water influence. Judging from the palynology, marine influ-ence seems to have been most significant in the basal parts of the member.
Sequence Stratigraphy The member is considered to represent Haq (1988) ’s sequences LZA 4.6 (Highstand) to LZB 1.5a (to Early Highstand) in the Q01 area. The start of Fourteens Claystone Member deposition is considered to be coincident with the southward expansion of the marine realm into the southern Dutch Central Graben. Deposition of the Weiteveen Formation in the Dutch Lower Saxony Basin is also considered to have started with this sequence. In the area where the Santpoort Member is encountered, the top of the Fourteens Claystone Member falls in the Late Highstand of LZB 1.1 or the Lowstand systems tract of LZB 1.2.
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].