|Premise||Definition extended after NAM and RGD (1980) .|
|Derivatio nominis||Named after the village of IJsselmonde, currently incorporated into Rotterdam.|
|Type section||Location map||See figure (pdf)|
|Depth||1034 to 1216 m|
|Length||182 m along hole|
|Reference||NAM and RGD (1980)|
|Definition||Massive sandstone, light-grey, very fine- to medium-grained, rarely up to pebbly, lignitic, locally glauconitic, locally with sideritic concretions, well bedded. Especially in the upper part of the member calcareous cemented beds are common; locally shells and shell fragments are present. Thin intercalated claystone beds are frequent. Often a 5 - 10 m thick lignitic claystone bed is present in this member..|
|Upper Boundary||The upper boundary, with the Eemhaven Claystone Member of the Vlieland Claystone Formation is equally sharp. .|
|Lower Boundary||The lower boundary, with the IJsselmonde Claystone Member of the Vlieland Claystone Formation, is taken at the base of the first massive sand.|
|Distribution||Southeastern West Netherlands Basin, especially in the Rotterdam area. The Vlieland Claystone Formation also is a lateral equivalent to the north and west (e.g. Berkel and De Lier oil fields), where the member can be recognised as a sandier interval in the Vlieland Claystone Formation|
|Age||Mid-Barremian in age. Characteristic dinocysts recorded are: Pseudoceratium pelliferum, Gardodinium trabeculosum and Odontochitina operculata.|
|Depositional Setting||A shallow-marine (shoreface-backbarrier) depositional environment is concluded for the lower parts of these deposits, associated with the upper-shoreface to back-shore of a coastal-barrier system prograding to the west and northwest. The intercalated claystones are consider-ed as back-barrier lagoonal deposits, with intercalated tidal deposits. The upper part of the member was depo-sited as reworked and bioturbated shallow-marine transgressive sands.|
|Sequence Stratigraphy||Represents the Highstand systems tract of sequence LZB 3.4, and the Transgressive systems tract of LZB 3.5. The thick, intercalated lagoonal shale is inferred to reflect the period of low relative sea level during the sequence boundary of LZB 3.5.|
|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].