Modelling of piggyback-basin stratigraphy: Record of tectonic evolution

Abstract

The tectono-stratigraphic evolution of foreland basins is influenced by processes acting on local, regional and global scale. In this paper the effects of these processes on the basin evolution are investigated using a forward reconstruction model based on the principles of balanced cross-section. The modelling incorporates the consequences of thrust deformation, sedimentation, erosion, basement subsidence, and sealevel changes on the basin stratigraphy. Basement subsidence due to lithospheric loading is the main cause of foreland basin formation, but appears to have minor implications for the occurrence of angular unconformities in the stratigraphie record of piggyback basins. Thrusting is probably the dominant factor in the control of the stratigraphie evolution of piggyback basins, overprinting the effect of eustasy. Detailed analyses of stratigraphie data enable the reconstruction of the structural evolution of the underlying thrust system. Modelling of the Northern Apenninic Po basin shows that Neogene stratigraphie sequences of the proximal part of the basin can be explained by tectonic activity of the Apenninic fold and thrust belt. Strong basement subsidence accompanied with deep-seated mid-Pliocene thrusting controls the stratigraphie record of the Po piggyback basins.