Why are geological maps important

Collect and evaluate geodata

Integrated geological survey of the land

We record the properties and structures of the subsurface using the integrated geological survey (IGL). We systematically and nationwide collect and evaluate data on the geology of the country through:

  • Shallow and deep holes
  • geological survey of sand and gravel pits, quarries, construction pits and road cuts
  • geoscientific interpretation of the terrain surface
  • geophysical measurement methods

All data flow into the specialist information system geology of North Rhine-Westphalia. From this we derive practice-oriented thematic maps.

Efficient mapping process

For more than ten years we have been using the integrated geological survey for our mapping projects. With this procedure, we collect all data for a project area that are important for regional planning: i.e. on geology, raw material, hydrogeology and engineering geology, geothermal energy and geohazards.

Many work steps are required to obtain a coherent three-dimensional image of the subsurface at great depths. First of all, we put all the information available in GD NRW together in a project room. We also procure geoscientific documents in public and private archives and evaluate them. If there are gaps in information and there is a need for investigation, field work is required to compress the data.

We evaluate the data collected, process it digitally and make it available in information systems. They can therefore be called up for a wide variety of requirements without page cuts and on a planning scale of 1: 50,000.

Current projects

The route of the ZEELINK gas pipeline offers a rare opportunity to examine the subsoil in long sections. From mid-2019 to 2021, one of the focal points of work has been to geologically record the ditch outcrops: from the German-Belgian border near Aachen-Lichtenbusch via Kempen, Voerde and Borken to Legden in the north-west of Münsterland. The route is run kilometer by kilometer. All important information on geology and soil as well as numerous layer profiles are recorded for our exploration and drilling database (DABO). Collected samples are analyzed in our laboratories. The evaluated data is made available in our information systems.

In the project areas 11 “Ruhrgebiet Nord” and 12 “Agglomeration Düsseldorf / Bergisches Land” of the integrated geological survey, the focus in 2021 will be on evaluating and incorporating the mapping results into the information systems. In the years before, the GD NRW carried out an extensive mapping program. With the exploratory bores of our own drilling rigs, we can reach depths of 25 meters in the Quaternary deposits. Under particularly favorable conditions, it can be up to 50 meters in exceptional cases.

In addition, we commission drilling companies with core drilling in order to obtain in-depth information down to depths of 100 meters and beyond. For special investigation purposes, we also carry out exploratory drilling outside the IGL project areas.

Drill cores enable a detailed description of the rocks and investigation of their age as well as their chemical and physical properties. Geothermal energy use, groundwater protection, hazard prevention - for practical use, the geodata of the boreholes flow into the digital geological maps.

Core drilling in 2021:

  • Eschweiler for the EU Interreg project Roll-out of Deep Geothermal Energy in North-West Europe

As soon as the drilling starts, we will keep you informed.


Enlarge graphic: Current project areas of the integrated
geological survey, PDF (120 KB)

Description of the project areas with availability of the data; PDF (200 KB)


Our mapping projects include as standard:

3D models of the subsurface

Geological structures such as rock strata, bodies of raw materials and groundwater or tectonic fault zones are three-dimensional. In the past, geological information could only be represented two-dimensionally by geological maps with supplementary profile sections. With modern geographic information technology, we can clearly visualize the geological structure in interactive 3D models. Here are a few examples