Tectono-Stratigraphic Evolution of a Shared Foreland Basin: A 3D Geomodel and Detrital Flux Reconstruction for the Pliocene-Pleistocene of the Po-Plain Basin (Northern Italy)

Abstract

The Po Plain Basin represents the shared foreland system of the Southern Alps and Northern Apennines belts, holding significant importance for geological research and energy resource management. We present a new basin-scale 3D geomodel of the Pliocene-Pleistocene succession, interpreted from an extensive dataset of seismic lines and well logs spanning the entire basin. This high-resolution model enables a detailed, quantitative analysis of tectonic deformation timing and sediment flux over the last 5 My. Analysis of the isobath and isochore maps documents that the Northern Apennines collision with the Southern Alps began in the early Pliocene, subsequently leading to the sequential fragmentation of the central foredeep into three distinct depocenters. Quantitative decompaction analysis revealed a very significant increase in sediment flux in the basin during the mid-Pleistocene despite a widespread decrease in tectonic activity. We propose that this increase was climate-driven, due to the combined effect of high-frequency, high-amplitude climate cyclicity predating the onset of major glaciations in the Alps and amplifying sediment supply. This work opens new questions about the age of transition from fluvial to glacial-dominated erosion in the Alps, and provides a new, quantitative tectono-sedimentary framework for the Po Plain, useful for better understanding the basin dynamics and consequent architecture.