VerLaPro – a 3D model of the shallow Paleozoic subsurface in the southern Ruhr Area

For decades the Ruhr Area in western Germany was dominated by extensive coal mining. Today, relicts of abandoned mines and the near-surface cavities are a hazard factor, for example at building sites. For an assessment of potential risks, the regional mining authority needs very detailed geological data. The calculation is based on the exact position of the coal seams at the Carboniferous surface and its loose rock covering. To provide this, a very detailed 3D model of the shallow Paleozoic underground is build, reaching down to about 100 m. The Upper Carboniferous coal-bearing units were influenced by multiple phase tectonics and these complex structures were challenging to visualise and to model. Heterogeneous data of old mining sites, including plans of mine shafts as well as data of surface opening shafts, are combined with existing geological data and a high-resolution digital terrain model (cell size 1 m) in SKUA-GOCAD software. Challenging for the modelling process are the variable data types, scales and spatial accuracies. For example, plans of the mine shafts are partly older than 200 years and passed through numerous processing steps which had an impact on the positional accuracy. To harmonise the data, a manual constructed profile section network is used and a homogeneous data distribution is developed. The result is a 3D model of the shallow subsurface in the southern Ruhr Area with complex tectonic elements, combining geological and mining data. In accordance with the Geologiedatengesetz (GeolDG, 2020) all results will be stored and published in a GIS-database.