Fault network of a buried rift-related structural high. Insights from multiscale 3D seismic analysis

Rift-related structural highs are widespread features of passive margins and foreland basins, where they exert first-order control on structural compartmentalization, stratigraphic architecture, and fluid migration. Despite their importance, the fault network architecture and damage distribution of buried highs are rarely constrained at the seismic scale because most examples are either deeply buried or strongly overprinted by later deformation. Once mainly investigated for hydrocarbons, structural highs are increasingly considered potential sites for CO2 storage and geothermal exploitation. Here we analyze the Gaggiano High, a buried Mesozoic structural high in the Western Po Plain (Italy), where limited Miocene inversion preserved the original extensional framework. We apply a multiscale 3D seismic workflow that integrates manual fault interpretation, throw–length scaling analysis, and curvature–derived lineament extraction. This approach allows us to characterize both seismic-scale faults and sub–seismic damage patterns. The fault system is dominated by N–S striking, east-dipping normal faults, complemented by NW–SE and subordinate E–W structures. Throw–length relationships show slopes between 1.1 and 1.4, with systematically higher throw-to-length ratios in deeper intervals, indicating mature and long-lived faults. Sub-seismic lineament analysis reveals a spatial anti-correlation between displacement and lineament intensity. Low-throw fault segments, linkage zones, and intersections coincide with lineament intensity peaks, consistent with distributed strain accommodation. These results demonstrate that inherited faults remained mechanically relevant throughout the tectonic evolution of the Gaggiano High, controlling the distribution of both seismic-scale displacement and sub-seismic damage. Our study highlights the value of multiscale seismic analysis for reconstructing fault–fracture architecture and for predicting strain localization and potential fluid-flow pathways in buried structural highs.