The geological map of the Netherlands shows the deposits and rocks that are present at or near the surface. The map covers the entire country, including the Dutch part of the North Sea. Map units represent (combinations of) formations (Fm), members (Mb) and beds. In the coastal region, stacks of Holocene deposits have been mapped as profile types. Profile type units can be recognised by the use of lowercase lettering in their codes.
Coversand (BX4: Boxtel Fm, Wierden Mb) and loess (BX5: Boxtel Fm, Schimmert Mb) are only shown if more than 2 m thick. The ubiquitous layer of actively transported open-marine sand (SB2: Bligh Bank Mb) is only shown if more than 7 m thick. Anthropogenic deposits are not shown on the map.
Besides near-surface deposits and rocks, a selection of fault lines and lines showing the maximum ice extent during previous glacial periods are also depicted on the map. Fault lines are only shown where clearly influencing current topography and/or delineating map units. Lines showing the maximum extent of the Weichselian (last ice age) and Saalian (second-to-last ice age) ice masses help to understand spatial relations between various map units.
Source data
The geological map is based on a multitude of published data, supplemented by recent information and new insights. For the onshore area, geological maps on a 1/50,000 scale (ca 1950-1997) and the 3D-subsurface models DGM and GeoTOP (1997-now) are the main source of information. Apart from that, the digital dataset on the Rhine-Meuse delta by Utrecht University, as well as various other data sources, have been used.
For the offshore area the main source of information is formed by the systematic mapping of the North Sea on a 1/250,000 scale (parts of the near coastal zone on a 1/100,000 scale) that was conducted between the end of the 1970s and 2003. This information has been supplemented by more recent research.
The individual borehole descriptions and cone penetration test results that form the base of the maps mentioned before are largely available through DINOloket.
Map application and reliability
The geological map is an overview map to be used on a national to regional scale. The actual mapping scale is 1/600,000. As such, the map provides a first insight into the shallow geology. For subsurface-related questions that require information on larger scales (subregional or local) and/or deeper below the surface, the user is referred to the information in the 3D subsurface models DGM and GeoTOP.
Current and earlier versions
This map is the successor of the General Geological Map of the Netherlands on a 1/600,000 scale (Zagwijn & Van Staalduinen, 1975), as well as more recent, modified versions of this map (Weerts et al., 2004; Schokker, 2010) that were made available online.
Contact
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References
Schokker, J. (2010) Geologische overzichtskaart van Nederland. Utrecht: TNO Bouw en Ondergrond.
Weerts, H.J.T., Schokker, J., Rijsdijk, K.F. & Laban, C. (2004) Geologische overzichtskaart van Nederland. Utrecht: Nederlands Instituut voor Toegepaste Geowetenschappen TNO.
Zagwijn, W.H. & Van Staalduinen, C.J. (1975) Geologische overzichtskaarten van Nederland: kaarten, profielen, toelichting. Haarlem: Rijks Geologische Dienst.