Hellevoetsluis Formation DCDH

 

Premise Unit, defined by Van Adrichem Boogaert and Kouwe (1995). This formation represents the deposits of the Dinkel Subgroup found in the western and central parts of the Campine Basin. Previously, these deposits were referred to informally by some oil companies as the ‘Twente Sandstone’.
Derivatio nominis Named after the Dutch town of Hellevoetsluis in the southwest of the province of Zuid-Holland, where the type well is located.
Type section Location map See figure (pdf)
  Well Hellevoetsluis-1 (pdf)
  Location N 51°51’28.3
E 04°10’20.2
  Depth 2957 to 3214 m
  Length 257 m along hole
Additional section Location map See figure (pdf)
  Well P13-01 (pdf)
  Location N 52°12’57.6
E 03°11’48.6
  Depth 1725 to 1880 m
  Length 155 m along hole
  Well De Lier-45 (pdf)
  Location N 51°59’06.9
E 04°13’33.1
  Depth 3766 to 3881 m
  Length 115 m along hole
  Well Sprang Capelle-1 (pdf)
  Location N 51°42’39.8
E 05°00’02.8
  Depth 2950 to 3033 m
  Length 83 m along hole
  Well Woubrugge-1 (pdf)
  Location N 52°09’49.6
E 04°33’34.2
  Depth 2765 to 3023 m
  Length 258 m along hole
  Well Werkendam-2 (pdf)
  Location N 51°47’29.7
E 04°50’22.1
  Depth 3355 to 3516 m
  Length 161 m along hole
Definition Succession of interbedded 1 to 15 m thick sandstone beds and silty to sandy, carbonaceous mudstones containing an occasional coal seam. The sand/shale ratio ranges between 0.2 and 0.6. Sands are predominantly grey or white, fine- to coarse-grained, well- to moderately-sorted and subangular. They occur in sheets and channel fills, locally stacked up to 30 m thick, with frequent metre-scale mudstone intercalations. Channel-sand log patterns are mainly bell-shaped, but compound or ratty patterns are also common. Truncated funnel-shaped patterns are commonly observed in the base of compound intervals. Mudstone intervals are predominantly greenish-grey or beige, frequently with purple or red-brown horizons in the their upper parts. Coal seams are rare, associated with grey claystone intervals of 5 to 55 m thick. The mudstone sections thin towards the northeastern margin of the Campine Basin (towards the Maasbommel High).
Upper Boundary The top of the formation is marked by a transition towards thick, greenish-grey or orange-red mudstones with fewer intercalated sheet sandstones, typical for the overlying Strijen Formation. The boundary is defined at the base of the first mudstone-dominated interval of more than 60 m thick. This diachronous change occurred earlier in the centre of the basin than along its margins.
Lower Boundary The contact with the underlying Maurits Formation is marked by the incursion of thick, argillaceous matrix-poor sandstone beds, commonly in combination with a decrease in the frequency of coal seams.
Correlation Towards the southeast of the Campine Basin, the Hellevoetsluis Formation grades into the Kemperkoul Member of the Maurits Formation, which is a coal-rich, finer-grained lateral equivalent. Possibly, the unit grades into the Tubbergen Formation in the central Netherlands (province of Utrecht).
Distribution Restricted to the central and western parts of the Campine Basin.
Age Early or Late Westphalian C, extending into the Early Westphalian D in proximal basin positions (e.g. Werkendam-2 (see pdf) ).
Depositional Setting Thick sandstone beds consist of sheets of amalgamated braided fluvial channel fills. Thin, fine-grained sandstone beds, associated with interchannel fines, reflect overbank deposits (crevasses, sheet floods). The mainly variegated flood-plain fines point to poorly- or fairly-drained soil conditions. The existence of local swamps is testified by the occurrence of some coal seams. The observed alternation of sandstone-dominated and mudstone-dominated intervals can be correlated on a local to regional scale, implying a depositional cyclicity. Massive fluvial sandstone intervals alternate with flood-plain-dominated sections. More proximal settings are found near the Maasbommel High - Zandvoort Ridge and towards the London-Brabant Massif. The south-western offshore exhibits a distal development (e.g. P13-01 (see pdf) ).
References See References Upper Carboniferous

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