Timing and mechanisms of sediment accumulation and pedogenesis: Insights from the Po Plain (northern Italy)

The relationships between pedogenetic processes and fluvial-coastal dynamics in the Po Plain have been reconstructed through sedimentological analysis correlation of ca. 170 core data chronologically constrained by 376 radiocarbon dates. Vertically stacked, weakly developed paleosols within Upper Pleistocene Holocene mud-prone strata testify to intermittent pedogenesis, periodically interrupted overbank sedimentation. Individual are laterally traceable for tens km exhibit A-Bk-Bw, A-Bk or A-Bw profiles. Stratigraphically ordered 14C calibrated ages from A organo-mineral horizons slow aggradation during 4–6 thousand years-long exposure periods. Burial ages, with an error few centuries, provided plant debris at top horizons. Millennial-scale climate oscillations glacio-eustasy main drivers pedo-sedimentary evolution area last 50 kyr. (P1-P3) well-drained floodplain environments, relatively warm Paleosol burial occurred colder phases. High-sediment-supply Last Glacial Maximum hindered pedogenesis led accumulation 3–10 m-thick strata. Widespread soil development (paleosol PH) end Maximum, following retreat Alpine glaciers afforestation Apennine drainage basins. At distal locations, paleosol PH was progressively buried under estuarine sediments phases post-glacial sea-level rise. Beyond marine influence, change a place another without specific spatial trends reflect upstream fluvial sedimentation dominated avulsions deposition spatially restricted alluvial units. (H1−H2) show poor potential variable degree maturity that avulsive patterns crevassing. This paper provides insights on timing mechanisms formation weakly-developed paleosols. outcomes this research applicable similar Quaternary systems, may help interpreting ancient paleosol-bearing successions.