Geological Mapping and Modelling

The Geological Mapping and Modelling Expert Group focuses on producing and harmonising pan-European geological maps and models to increase our understanding of the geology of Europe.

What, Why, How...

The Geological Mapping and Modelling Expert Group (GMMEG)

Geological maps are the language of geology. Geology is perhaps the most diverse of sciences, encompassing the interactions between the geosphere (the Earth), hydrosphere, atmosphere, biosphere, and cryosphere. If we imagine all the fields of the geological sciences – for example, mineral resources, geological hazards, groundwater, geoenergy, and many more – as the chapters of a book, geological maps and models would be the language in which the book is written. To allow us to speak the same language, to be understood, when we talk about these diverse geoscientific fields, it is important that we have maps that continue seamlessly across national borders, maps that are created using common standards. The resulting maps can then be understood by all, and on a pan-European scale.

But making seamless geological maps is not a simple task. National geological survey organisations have been making geological maps for decades and, in some cases, for more than a century. And those maps have been produced at different scales, using different techniques, standards and vocabularies for the same geology, and for different purposes. Often, there are mismatches between maps that meet at national borders, or at the land-sea boundary where geological maps also extend offshore. These mismatches occur because of the different approaches that have been used to make the maps. It is a primary goal of the GMMEG to use our pan-European geoscientific network to produce better, seamless maps that meet modern data standards and that serve as the basis for making informed decisions that depend on understanding the geology of Europe.

The GMMEG is actively working on the following aims:

  • Developing standardised, hierarchical geological names (scientific nomenclatures)
  • Sharing best practice data-models and a reference data-model
  • Using automated tools for showing digital maps at different scales in a study area
  • Developing new seamless digital geological models and datasets in a study area
  • Developing tools to describe uncertainty in geological maps and models
  • Promoting geological mapping and modelling

The datasets that the GMMEG produces are models of the geological architecture of the surface and subsurface of the Earth. The information contained in those models includes lithology (the rock type), lithostratigraphic units (subdivisions of the geology as they are shown on maps), age (of rocks and geological events such as volcanism, or tectonic plate movement), geological structures (such as faults and thrusts), geomorphological features (the shape of the surface, caused by interaction with water, ice, and the atmosphere) and more.


Working together to produce harmonised modern
digital maps and models at pan-European scale, the GMMEG provides a geological baseline that all European geologists can use as the context for their research. The GMMEG’s work delivers the framework necessary for any European decision-making that relies on understanding the rocks beneath our feet.

Our projects

EuroGeoSurveys has worked on many EU co-funded projects to harmonise geological datasets across Europe. The results of those projects are hosted in EGDI and include, for example, the OneGeologyEurope onshore geological map dataset of many European countries at a scale of 1: 1 million, the EMODnet marine geological map dataset, and GeoERA datasets, along with other European map datasets such as the International Geological Map of Europe in scale 1: 5 million (IGME 5000). Nevertheless, data gaps are huge and the GMMEG continues to develop the framework of sound scientific vocabularies, datamodels and workflows, necessary for pan-European data harmonisation.

Within EuroGeoSurveys, the ongoing efforts to harmonise basic geological data are undertaken primarily by the GMMEG and the MGEG, with the strong support of the SIEG.