Quantitative comparison of subsurface structures: an application to salt domes and crystalline bodies

Structural geological models are valuable instruments to visualize the subsurface for various scientific and economic interests. However, as geomodels only represent potential realizations of subsurface conditions, quantitative comparison of multiple probable models or model scenarios is important. This study applies an algorithm for the geometric shape quantification. The method quantitatively assesses the geometry of geological structures based on cross sections oriented perpendicular to the structures' horizontal main axes. The resulting data are analyzed and clustered statistically: Histogram analysis of dimensional data provides insight into the anisotropy of structures, the presence of overhangs and the character of the top surface of the structures. Gradient and curvature data offer insight into the slopes of the lateral walls of the structures and their sphericity as well as top surface. Cluster analysis reveals geometric affiliations, as the methodology is applied to 239 datasets of intrusive salt geometries from the North German Basin and 67 datasets of crystalline basement structures from Saxony (Germany). The resulting clusters are assigned to a catalogue of benchmark models exhibiting high geometric similarity. The cluster results are contextualized in the regional geology of the North-German Basin and the basement of Saxony in Germany. The relation of geometric statistics and regional geology demonstrates the application of the catalogue of benchmark models to model geological bodies.