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We examined downstream trends in sediment composition within the modern Po River system and defined provenance changes within a selected sector of the Upper Pleistocene to Holocene coastal plain in response to paleogeographic reorganisation during the last glacial-interglacial cycle. Sediment composition of the Upper Pleistocene to Holocene alluvial and coastal plain succession overlaps with the modern petrofacies, suggesting that ancient fluvial sand was sourced from a dynamic river system attributable to a distal paleo-Po with episodic sediment input from South Alpine and Apennine rivers. In the wave-dominated estuarine depositional system developed under transgressive conditions, Po-derived detritus mixed in the coastal system with sediment fed by Central/Eastern Alpine rivers, which was redistributed southwards by alongshore currents. A similar, mixed composition of late Holocene highstand depositional systems reflects the progradation of Po delta lobes (similar in composition to Po River sands) and adjacent strandplains (typified by sediment mixing due to alongshore transport). Compositional variability across the main stratigraphic surfaces suggests that autogenic processes (e.g. marine reworking, sedimentary mixing, delta switching/abandonment) in turn influenced by glacioeustasy, controlled the development of the transgressive and highstand Po Plain succession. This study clarifies the effect of fluvial-marine interaction during the Holocene evolution of the Po coastal system and can be used as a model to interpret the evolution of many mixed-delta types and Quaternary successions that shows alternating river-flood and wave-dominated deposits.

The Ficoncella site in northern Latium (Italy) represents a unique opportunity to investigate the modalities of a short occupation in an alluvial setting during the Lower Palaeolithic. The small excavation area yielded a lithic assemblage, a carcass of Palaeoloxodon antiquus, and some other faunal remains. The main objectives of the study are to better characterize the depositional context where the Palaeoloxodonand the lithic assemblage occur, and to evaluate with greater precision the occupation dynamics. A 25 m-long well was drilled just above the top of the terrace of the Ficoncella site and faunal and lithic remains were analyzed with current and innovative techniques. The archaeological site contains floodplain deposits as it is located next to a small incised valley that feeds into a larger valley of the Mignone River. A tephra layer capping the site is 40Ar/39Ar dated to 441±8 ka. Collectively, the geochronologic, tephrochronologic and geologic data, suggest the site was occupied during MIS 13. The new results should prompt further research at Ficoncella in order to improve our understanding of the dynamics of human settlement in Europe during the Early to Middle Pleistocene.

We use Unconformity Bounded Stratigraphie Units (UBSU) to reconstruct the chronostratigraphy of volcaniclastic deposits of Roccamonfina Volcano (southern Italy). Significant discontinuities of different hierarchical order in the stratigraphic succession of the volcano have allowed us to identify the UBSU supersynthems, synthems and subsynthems. The hierarchical order has been determined by the importance and duration of the discontinuities bounding such units and by their geographic distribution. Supersynthems are bounded by regional-scale unconformities that may correspond to important tectonic events, changes in the style of eruptive activity or volcano-tectonic collapses. Synthems are bounded by unconformities marked by paleosols that are representative of considerable hiatus and extended all over the synthem. They are composed of complex sequences of depositional units. At Roccamonfina the synthems reveal cyclical eruptive activity. Unconformities bounding the subsynthems have been recognized through a detailed facies analysis. More than 100 stratigraphic sections have been analyzed and correlated, restoring them to single successive datum planes. It has been possible to reconstruct the original stratigraphic relationships, the geometry of the units, and the effects of syn-eruptive tectonic activity. This procedure revealed that the unconformity surfaces bounding depositional units show different physical expression in the proximal, medial and distal areas: (a) erosive surfaces may become amalgamation surfaces; (b) amalgamation of several depositional units can locally produce a single lithostratigraphic unit. In this case the unconformity surfaces bounding the units can be identified by the presence of discontinuous pumice and lithic concentration zones; (c) non-depositional surfaces in proximal areas (bypassing surfaces) or in interfluve areas may correspond to downslope deposits; (d) unconformity surfaces can bound different lithostratigraphic units that are the result of down-current facies variation. The pyroclastic units at Roccamonfina are organized as forestepping-backstepping sequences. We interpret this organization as resulting from waxing-waning processes associated with eruption and emplacement. In fact, the internal geometry of each synthem indicates a forestepping phase until the maximum eruption rate is achieved; as it later declines deposition occurs upslope (backstepping). This mechanism is also reproduced at smaller scale within each subsynthem. The forestepping-backstepping organization of the deposits provides an explanation for the variability of physical, chemical and sedimentological parameters observed in the Roccamonfina volcaniclastic deposits.