New insights on late Quaternary palaeogeographic setting in the Northern Adriatic Sea (Italy)

Abstract

Sedimentological, geochemical and micropalaeontological data from sediment cores in the northwestern Adriatic Sea were obtained to reconstruct the stratigraphic framework and palaeogeographic setting during the last post-glacial sea-level rise (14000-6000 yr BP). Four lithostratigraphic units were identified: (a) distal plain deposits (>14000 yr BP), submerged during the first phases of marine ingression; (b) coastal lagoon system; (c) barrier-lagoon system, which is dated back to between 10019 AE 61 and 10228 AE 174 cal. yr BP from 14 C dating on peat and shell remains; (d) marine prodelta deposits (<5500 yr BP). Geochemical data allow the identification of three distinct sediment sources: River Po, River Adige and Eastern Alpine rivers characterised by decreasing Ni/Mg ratios (50-70, 8-15 and 5-10, respectively) and Ba/Al ratios of 45-55, 55-65 and 35-45, respectively. The three sources display different relative abundances in time. During the Lateglacial, the Po is the main sediment source for the southern cores, whereas the Eastern Alps and the River Adige are the main sediment sources for the northern cores. This suggests a northern position of the Po River bed compared to previous studies. Coastal drowning led to a homogenization of the provenance signal within the sediments. Only after the marine transgression does a River Po signal appear in the northern cores. At the same time, in the southern cores the signal of Eastern Alpine rivers becomes stronger. Transgressive barrier-lagoon and recent sediments do not display a predominant signal for provenance indicators.

Sediment composition, provenance, and Holocene paleoenvironmental evolution of the Southern Po River coastal plain (Italy)

“…APP sources are characterized, instead, by low Cr and Ni values (Amorosi et al, ), with relatively high CaO and Sr contents from the Miocene Marnoso‐arenacea turbidite Formation of the Romagna Apennines (Dinelli & Lucchini, ; Lancianese and Dinelli, 2015). NAD sediments have MgO as a tracer, because of the dolomite‐rich rocks dominating river catchments (Curzi et al, ; Picone et al, ). Barium was also suggested as a possible proxy for NAD provenance: In particular, it was used as an Adige River tracer (Amorosi et al, ; Picone et al, ).…”

“…In order to define sediment provenance of shallow‐marine deposits, binary plots of MgO/Al 2 O 3 versus Ni/Al 2 O 3 concentrations from modern prodelta sediments (Picone et al, ; Spagnoli et al, ) were plotted against shallow‐marine deposits (facies association M) from this study (Figure a). Based on the geochemical composition of the three river end‐members (black squares in Figure a), it is possible to identify four clusters of modern sediments (Figure a), corresponding to Po River source (red circle), Apenninic origin (green circle), North Adriatic provenance (yellow circle), and mixed composition (orange color), this latter with MgO/Al 2 O 3 ratios of 0.4–0.6.…”

The aquatic leaf beetle Macroplea mutica (Coleoptera: Chrysomelidae) in Europe: Population structure, postglacial colonization and the signature of passive dispersal

“…This might hint at an only moderate separation of the two refugia, as postulated for other organisms (Taberlet et al, 1998;Schmitt et al, 2005). If the northern end of the Adriatic Sea was a continuous swamp during the last ice age (Gliemeroth, 1995;Picone et al, 2008) then it is possible that M. mutica was continuously distributed throughout South-eastern Europe.…”

Tracing provenance and pathways of late Holocene fluvio-deltaic sediments by heavy-metal spatial distribution (Po Plain–Northern Apennines system, Italy)

“…Recent studies conducted in the openmarine tract (the Adriatic Sea) suggest that the ophiolitic signature (i.e. high natural Cr and Ni concentrations) identified from the Apenninic catchments to the delta may serve as a reliable provenance indicator for other components of the system, such as the prodelta (Amorosi et al , 2008, the shelf (Picone et al 2008) and the deepmarine environment (Lucchini et al 2003). An additional Cr and Ni contribution to the Adriatic Sea (Prohic & Juracic 1989;Rivaro et al 2004) is expected from the eastern Adriatic catchments (Albania, Croatia), which drain huge volumes of Cr-and Ni-rich ophiolitic material from the Dinaric chain (Lužar-Oberiter et al 2009).…”