The map was generated as part of the GARAH 3D basin model. A detailed description of the model parameters and method can be found in the project deliverable D2.4 (https://repository.europe-geology.eu/egdidocs/garah/garah_deliverable_report_d24_3d_petroleum_model_un.pdf). It was exported from the GARAH Petromod 3D model with the overlay export function in ascii grid format. The export parameters were set to the Sweeney & Burnham (1990) Easy%Ro overlay, “top of layer” of the Upper Jurassic at present-day. The coordinate system of the model was set to UTM31 ED50. The map was subsequently reclassified using the reclassify tool in ArcGIS to show the intervals 0-0.55 %Ro, 0.55-0.7 %Ro, 0.7-1.0 %Ro, 1.0-1.3 %Ro, 1.3-2.0 %Ro, 2.0-4.0 %Ro, 4.0-5.0 %Ro.