Structural evolution of the Gaggiano High. A preserved rift‐related structural high in the Western Po Plain (Italy)

The Gaggiano High, buried beneath the sediments of the Western Po Plain (northern Italy), represents one of the few examples of Mesozoic structural highs largely preserved within a foreland–foredeep system. Unlike the adjacent Lacchiarella Basin, which underwent strong positive inversion during the Neogene, the Gaggiano High experienced only mild contractional reactivation, allowing its original extensional framework to be preserved. By integrating 3D seismic interpretation, isochore maps, and well data, we reconstruct the tectono-stratigraphic evolution of the Gaggiano High from Middle Triassic rifting to Neogene burial. Isochore maps and stratigraphic geometries reveal major thickness variations and westward tilting along N-S faults during Early to Middle Jurassic extension, followed by long-lasting structural uplift and reduced sedimentation during Jurassic-Cretaceous times. In the Paleogene, renewed extension along NW–SE faults produced local depocentres within the Scaglia Fm., while subsequent Oligo-Miocene compression resulted in gentle folding, minor inversion of inherited normal faults, and regional tilting. Comparison with the exhumed Lugano Swell highlights the long-term persistence of rift-related highs as mechanically rigid domains within evolving foreland basins. The Gaggiano High thus provides a well-preserved subsurface analogue illustrating how inherited normal faults and long-lived structural highs may constrain, modulate, or even inhibit subsequent deformation, stratigraphic architecture and basin evolution across the Alpine-Apennine system.