The Pleistocene-Holocene Transition in the Po Plain (Italy): Stratigraphic Architecture and Sequence Stratigraphy from a Highly-Subsiding Basin

This work focuses on the Late Pleistocene-Holocene transition in the southern Po Basin. Five areas were investigated, with the aim of unraveling the role of different allogenic factors (climate, eustacy, sediment supply) on stratigraphic architecture in the last 45 ky. The study starts from the distal portion of the basin (the coastal plain deposits) and then moves towards increasingly internal areas: the alluvial sector characterized by the Po channel belt deposits, and the mud-prone interfluvial succession between the Apenninic margin and the Po channel belt. In the coastal sector, high-resolution facies analysis, along with a well-constrained chronostratigraphic framework, led to the accurate paleoenvironmental reconstruction of the last 45 ky BP depositional history along the 93 km-long transect. It is also provided a sequence stratigraphic interpretation for the whole sedimentary succession. In the Po channel belt sector, based on 28 radiocarbon dates, facies interpretation from high-quality core descriptions and freshly-drilled continuous cores, the contrasting stratigraphic architecture of Late Pleistocene and Holocene deposits was highlighted. Changes in lithofacies and channel stacking patterns reveal the vertical superposition of amalgamated fluvial-channel sands (Late Pleistocene) and mud-dominated deposits (Holocene), with isolated fluvial-channel bodies. We also attempted to establish the link between facies architecture, sea-level fluctuations and climate changes. The 3rd study area (interfuvial succession) was selected to test a new method for paleosol identification, on the basis of geotechnical properties generated from pocket penetrometer values. Through the reconstruction of the Biferno coastal deposits (4th study area, located ca. 300 km south of the Po Plain) we had the opportunity to document two coeval (Late Pleistocene - Holocene) coastal sedimentary successions, diverging in terms of shelf gradient and proximity to the LGM-lowstand Po Delta. The 5th study area, broadly coincides with Ferrara, was selected to show how high-resolution stratigraphic studies can be used for aquifer protection.