A seismic interpretation and mapping study has reconstructed the tectonostratigraphic evolution of the Danish onshore and nearshore areas comprising the Danish Basin and the northern part of the North German Basin, separated by the Ringkøbing–Fyn High, based on seismic, wireline log and lithological data. Based on well and legacy 2D seismic data released prior to 2022, 20 regional seismic horizons defining 17 stratigraphic units were interpreted. The composition of the units was determined from wireline log interpretation and lithological information by tying the seismic horizons to the wells. The compiled 3D geological model, composed of surfaces and units with a cell size of 400 × 400 m, forms the basis for 15 depth and 15 isochore maps. The resulting maps/grids were interpreted and mapped in Petrel (versions 2015–2024) in two-way time, smoothed, depth-converted and exported in ZMap+ ASCII grid format as .DAT files in the ED50z32, SIS,501081 projection. These regional depth and isochore maps are named to correspond to the figure numbers in the associated publication and provide, together with major faults, a robust foundation for future exploration activities, such as storage of CO₂, hydrogen, natural gas, radioactive waste etc., as well as utilisation of geothermal resources. Furthermore, the maps give a good regional overview of, for example, potential reservoir intervals (lithostratigraphic units). A more comprehensive assessment of subsurface use in a specific area must be based on detailed analysis of local data and their incorporation into local geological models. Some of the maps have been used as basic input for the web-based Geographic Information System geothermal portal hosted by the Geological Survey of Denmark and Greenland (
WebGIS Portal; Deep Geothermal Energy). These maps and selected faults are intended only for regional use and to give a good indication of where in Denmark subsurface use is relevant. Many areas have sparse and/or poor-quality data, and therefore no attempt has been made to develop detailed local models or to eliminate negative isochore thicknesses and uncertainties, e.g. around fault and salt structure interpretations. These grids are provided without guarantee as to their accuracy or suitability for the user's purpose and GEUS assumes no liability arising from their use.
