Schieland Group SL


Premise Group defined by van Adrichem Boogaert & Kouwe (1993). This group comprises all mainly continental Upper Jurassic and Lower Cretaceous deposits. It contains both the former Delfland Group and the former Central Graben Group. Herngreen and Wong (1989) indicated that all mainly continental deposits should be placed in one group. Here, a new group is created because significant controversy exists about using either the name ’Delfland’ or ’Central Graben’ throughout the Dutch territory, since previously both had only been applied in a geographically restricted sense. Consequently, the status of the Delfland and Central Graben Groups was down-graded to that of a subgroup.
Derivatio nominis Named after the polder authority of Schieland, in the heart of the province of Zuid Holland, between the cities of Gouda and Delft.
Type section Location map See figure (pdf)
  Well Nieuwerkerk-1 (pdf)
  Location N 51°57’00.1
E 04°37’32.3
  Depth 1052 to 1942 m
  Length 890 m along hole
  Reference NAM and RGD (1980)
Additional section Location map See figure (pdf)
  Well F03-03 (pdf)
  Location N 54°50’45.5
E 04°42’29.3
  Depth 2547 to 3652 m
  Length 1105 m along hole
  Reference Herngreen and Wong (1989); Munsterman et al. (2012)
Definition Group of formations, consisting of grey and variegated claystones, coaly to clayey sandstones, rare coal seams (associated with grey claystones), and locally calcareous intercalations, deposited in a predominantly continental to paralic environment.
Upper Boundary In most of the southern Dutch Central Graben and Terschelling Basin (see pdf) the Scruff Group more or less conformably covers the Schieland Group. Elsewhere the Rijnland Group conformably, or locally unconformably covers this group, except in strongly inverted areas, where the Chalk Group or Lower North Sea Group unconformably rests on this group.
Lower Boundary In the major part of the Jurassic basins this succession unconformably overlies the Altena Group. On elevated blocks, and outside these basins, the group may rest on deposits of Triassic or Permian age.
Distribution This group occurs in all Jurassic basins except the Lower Saxony Basin, where the Niedersachsen Group is the lateral equivalent. The group interfingers with the Scruff Group in the Vlieland Basin. In the Broad Fourteens Basin and West Netherlands Basin intertonguing with the Rijnland Group is seen. In the Central Netherlands Basin and Vlieland Basin the lithofacies associations of the Schieland Group increasingly resemble those of the Niedersachsen Group of the Lower Saxony Basin (see pdf).
Age The age of the deposits of this group varies with geographic location. In the northern part of the Dutch Central Graben, The age of the deposits of this group varies with geographic location. In the northern part of the Dutch Central Graben, Schieland Group (Central Graben Subgroup) deposition is of Callovian to Early Kimmeridgian age, Munsterman et al. (2012). In the southern Dutch Central Graben and Terschelling Basin, Schieland Group deposition falls in the late Callovian-Early Volgian, Munsterman et al. (2012). In the Vlieland Basin  this group was deposited during the Ryazanian Herngreen, Smit and Wong (1991). In the Central Netherlands Basin deposits of Middle Volgian - Valanginian age are found. In the Broad Fourteens Basin the Schieland Group has a Kimmeridgian - Valanginian age. In the West Netherlands Basin it generally has a Middle Volgian - Ryazanian age at the base, although locally thin Oxfordian to Early Volgian deposits can be present. Early Barremian ages are recorded from the uppermost part. In the Roer Valley Graben, erosional remnants of sediments of the Delfland Subgroup of Oxfordian - Volgian age have been observed, although the main period of sedimentation commenced in the Early Ryazanian, and ended in the Barremian, NAM and RGD (1980).
Depositional Setting Paralic to continental environment, but some restricted-marine (lagoonal) intercalations occur, especially around the boundaries with adjoining marine units.
Subdivision The Schieland Group is subdivided into two subgroups. The Central Graben Subgroup contains all formations of the Schieland Group that have been deposited in the Dutch Central Graben and Terschelling Basin. The Delfland Subgroup comprises those formations that are found in the Vlieland Basin, Central Netherlands Basin, Broad Fourteens Basin, West Netherlands Basin and Roer Valley Graben. The boundary between the two subgroups is placed on the Vlieland High, between the Terschelling Basin and the Vlieland Basin (see pdf) .
  SL Schieland Group
  SLC Central Graben Subgroup
  SLCF Friese Front Formation (amended)
  SLCP Puzzle Hole Formation
  SLCU Upper Graben Formation
  SLCM Middle Graben Formation
  SLCL Lower Graben Formation
  SLD Delfland Subgroup
  SLDN Nieuwerkerk Formation
  SLDB Breeveertien Formation
  SLDZ Zurich Formation
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.

Nomenclature of the Netherlands and D.K. Munsterman, R.M.C.H. Verreussel, H.F. Mijnlieff, N. Witmans, S. Kerstholt-Boegehold & O.A, Abbink (2012), Revision and update of the Callovian-Ryazanian Stratigraphic Nomenclature in the northern Dutch Offshore, i.e. Central Graben Subgroup and Scruff Group. Netherlands Journal of Geosciences-Geologie en Mijnbouw, 91 (4):555-590.
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