Alterations

The renewed Stratigraphic Nomenclature covers the entire stratigraphy of the Dutch subsurface. Previously there was 'Shallow Nomenclature' and 'Deep Nomenclature' that overlapped in the Cenozoic. Both versions used a different coding system for the stratigraphic units. The renewed integrated Stratigraphic Nomenclature ends the distinction between 'Shallow' and 'Deep'. The Nomenclature now follows the same template from the very youngest to the very oldest units. All information is available in both Dutch and English.

As a result of the removal of the distinction between 'Shallow' and 'Deep', stratigraphic definitions of units found in both nomenclatures have been rewritten. In addition, the codes of the units in the Cenozoic have been adapted. With the publication of the new Stratigraphic Nomenclature, some changes to the content have also been made, especially in the Middle North Sea Group and the Lower North Sea Group. All changes resulting from the publication of the new Stratigraphic Nomenclature have been collected in a table.

Previous nomenclatures

The renewed Stratigraphic Nomenclature is the source for current stratigraphic information as used by TNO – Geological Survey of the Netherlands for mapping and modelling. The online Nomenclature will be updated regularly. Larger changes in content will lead to archiving of previous versions. By means of an archive function, previous versions can always be viewed. From now on, all previous paper and digital Nomenclatures are out of date. The previous versions can be found under 'Previous versions' in the menu on the left.

Geological background information

Geological and structural information is no longer part of the Stratigraphic Nomenclature. Such information can be found in peer-reviewed publications and in publications such as the book 'Geology of the Netherlands' that is currently being updated. Where possible, relevant publications on stratigraphy and geology of the Netherlands will be shared on this website. Stratigraphic overview charts and maps with structural elements can be found under 'Stratigraphic charts' in the menu on the left.

New distribution maps - working method

All the distribution maps of the renewed Stratigraphic Nomenclature are new. The compilation of the distribution maps was done on a national scale, aimed at publication on paper format A4. Details that are not visible on this relatively large scale have been generalized or not reproduced. For the distribution maps of units of the North Sea Supergroup (N) a different procedure was followed than for the older units. Roughly speaking, the division comes down to this:

  • North Sea Supergroup: the distribution maps are based on existing distribution maps, mainly from the Digital Geological Model (DGM). DGM+ was also used. DGM+ is based on a larger number of drillings than DGM. For the Upper North Sea Group (NU), the distribution in the North Sea (Netherlands Continental Shelf, NCP) is not yet shown in the maps. Drillings used for the distribution maps of the Upper North Sea Group (NU) are not shown on the maps due to the large number of drillings.
  • Older than North Sea Supergroup: the distribution maps are based on wells (boreholes) and seismic data; this is in fact a new mapping on a national scale of the units at formation and member level. For these units, the wells in which units were found are also shown on the maps. For the mapping procedure, wells in which a unit was not found were also used. These are not shown.

Available geological knowledge and information from scientific publications were also used to produce the distribution maps.

The data used for the distribution maps of the Upper North Sea Group are summarized in a table.