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Abstract: The coasts of the Mediterranean Sea are characterized by the presence of many archaeological remains (ports, protection structures, villas, fish tanks, etc.) that have been emplaced since the Roman Age and have persisted until present day. Due to their archaeological value, these structures represent an inestimable cultural heritage at regional and national scale. As consequence of local sea level variations, most of these structures are today submerged and, for this reason, they represent an important geo-archaeological proxy for the reconstruction of the ancient coastal landscape. Nevertheless, marine processes, such as coastal erosion and/or flooding, are among the main factors contributing to their damage and, hence, protection and conservation strategies need to be enhanced. In this paper, the vulnerability to marine factors of five coastal archaeological sites has been assessed. The investigated sites are located along the Posillipo Hill, one of the most beautiful and attractive coastal sector in the Gulf of Naples (Southern Italy). The analysis has been carried out by applying a vulnerability index method, which is based on the combination of a number of different indicators accounting for both marine processes and the typology of the remains. The results of this study allowed identifying the most vulnerable sites that require, for their conservation and sustainable usability, urgent management strategies. Graphic abstract:

An integrated morpho-stratigraphic approach has been used to reconstruct the Quaternary history of the Boiano basin, the largest tectonic depression of the Molise Apennine (Italy). Lacustrine, marshy and fluvial environments alternate all along the investigated infilling succession as a response to tectonic subsidence, volcaniclastic inputs and climate changes, from ca. 500 ka. Two tephra layers 40Ar/39Ar have been dated and referred to the Middle Pleistocene explosive activity of the Roccamonfina volcano, while a younger tephra layer has been related to the Campi Flegrei Neapolitan Yellow Tuff (ca. 15 ka). Pollen analysis has highlighted the vegetation changes related to the 100 ka glacial–interglacial cyclicity, between MIS 13 and 2. From 500 to 350 ka, a strong subsidence led to lacustrine deposition, while between 350 and 250 ka, a decrease in subsidence rates caused the transition to fluvial–marshy conditions and, at a later stage, to floodplain environments. The analysis of palaeosurfaces allowed the geomorphological evolution of the basin to be reconstructed since the Middle Pleistocene and the morpho-sedimentary events to be related to the SW-NE extensional tectonics affecting this sector of the central-southern Apennine. This tectonic behavior is also testified by the differential subsidence rates recorded within the basin through the analysis of two deep cores drilled in the center of the Boiano town.

Abstract: The Sele river plain is located along the western Tyrrhenian margin of the southern Apennine Chain and is confined seaward by a straight sandy coast formed during the Last Interglacial and the Holocene. The coastal plain is characterised by beach-dune ridges which interfinger landwards with lagoon and fluvio-palustrine deposits. This belt, which progressively grew up, represents the evolution of a barrier–lagoon system alternatively shifting landwards and seawards. The knowledge on the Holocene evolution of the Sele river coastal plain, along the coast of the Poseidonia-Paestum archaeological area, was improved by the drilling of two new cores and the collection of several archaeo-tephro-stratigraphic data. The area experienced the Holocene marine transgression which cut high cliffs in the travertine deposits. During the second half of the Holocene, the shoreline shifted seawards and a lagoon–beach bar system (Fossa Lupata-Laura) formed. The archaeological remains (VI cent. b.c.) and the Agnano Monte Spina tephra layer (4.1 ky BP) constrain chronologically this morpho-sedimentary system. After the VI cent. b.c., and mostly after the deposition of the 79 a.d. tephra layer, the shoreline shifted seawards and an additional beach ridge formed, while the flat area at the back (Fossa Lupata) was rapidly aggraded and dried up.

Abstract: The travertines on which the ancient town of Paestum was built about 2,600 years ago, have been investigated to restore the original sedimentary environment of these freshwater limestones formed during the Late Pleistocene–Holocene in the southern sector of the Sele River plain. For this purpose, the few present outcrops of travertine have been analysed from a palaeoenvironmental point of view, integrating the morphology and the sedimentology of the substrate with the information on the textural patterns of the blocks forming the town walls, some of which have a clear similarity with the outcropping substrate. The Paestum travertines can be distinguished into two sedimentary units: the lower Paestum travertines (LPT) which formed between Late Pleistocene (75,000 years BP) and the Early Holocene, and the upper Paestum travertines (UPT) formed during Late Roman to Medieval times. The UPT reached various meters of thickness within the southern and western part of the town, obstructing completely its western entrance, Porta Marina, with its flanking side towers, and were largely removed during archaeological excavations that started in the 1930s. A possible mechanism for this fossilization calls for a process of progressive upward growth of an incrustation barrier within the door, while the calcariferous waters were flowing out from the town at increasing heights.

Abstract: As in other alluvial coastal plains in Italy, the Holocene evolution of the Sele River coastal plain was strongly controlled by the events occurring after the Last Glacial Maximum (ca. 19 ky) when, because of progressive sea-level rise, marine transgression affected the outer portion of the present plain. From the Middle Holocene (ca 5.0–6.0 ky BP), the decrease in the sea-level rise led to coastal progradation testified by the building and the seaward migration of a barrier-lagoon system formed by the composite Sterpina–Laura beach-dune ridge system and the back-ridge flat area behind it, characterised by lagoonal to marsh environments. The present paper deals with the reconstruction of the coastal evolution focusing on the last 3,000 years. Geomorphological and geoarchaeological data were used to constrain the evolution of the area in remote times, while the analysis and comparison of historical and recent topographic maps, orthophotographs and aerial photographs allowed to highlight the shoreline trends in recent centuries. The coastline changes that occurred along the Sele River coastal plain during the last 3,000 years highlight two main evolutionary trends in time: firstly a coastal progradation and then a coastal retreatment which has recently been followed by a phase of substantial coastline stability. The coastal progradation (up to 500 m ca.) was favoured by the increased amounts of fluvial sediments delivered to the Sele coast because of the increase in agricultural activity and of periods of climate deterioration (the last being the Little Ice Age). During the last 150 years the Sele coast has been affected by prevailing erosion. From 1870 to 1984 the shoreline progressively retreated, reaching the highest erosion rates around the main river mouths. This shoreline retreatment can mainly be related to human activities (land reclamation, dam building, urbanisation) that reduced the quantity of sediment delivered to the coast. Due to this recent shoreline retreatment, even the historical dune system was locally affected by erosion too. Since 1984 the shoreline has been fairly stable while the Sele mouth zone has experienced erosion.

Abstract: In order to assess the effects of possible future sea-level rise in the Sele plain, the lowlands prone to inundation and the rate of coastal erosion in the years 2050 and 2100 have been discussed and some conclusions are here proposed. The sea level at these two dates was calculated as the combination of three components: response of Italian coastal zones to the past deglaciation, variations in ocean volume due to the global warming and vertical land movements. The morpho-stratigraphical data, chronologically supported by 14C and by archeo-tephro-stratigraphical dating, have allowed the identification of paleo-sea levels of the upper Pleistocene and Holocene (Amato et al. 2011). Such paleo-sea levels compared with those of the tectonically stable areas (Lambeck et al. 2011), permitted the detection of the different vertical land movements in the study area. In particular, in the SE sector of the coastal plain, the Holocene paleo-sea levels are slightly higher (ca. 1–2 m). These values could be considered due to a gentle uplift of the area during Holocene times (0.22 mm/year). In the central sector of the plain, near the Sele river mouth and in the NW sector, between the Sele and Tusciano river mouths, the altitude of the Late Quaternary coastal and lagoonal deposits are slightly lower (ca. 2–3 m). These values could be related to a gentle subsidence of the area during the Holocene (0.4 mm/year). The sea level rise of 5.9 mm/year (IPCC 2007) and 14 mm/year (Rahmstorf 2007) was considered to represent the maximum trends in the ocean volume variation at global scale. The third component, the glacio-hydro-isostasy, was represented by the value of 0.44 mm/year identified by Lambeck et al. (2011) at the Sele plain. The sum of these three components allowed to identify three sea-level scenarios slightly different for the northern and the southern sector of Sele plain, with values ranging from 357 to 1,526 mm and from 307 to 1,424 mm, respectively. For each scenario a simple approach was used, mainly based on the topographic elevation analysis of study area, applied to identify the extension of possible areas of inundation. It corresponds to a minimum value of about 0.42 km2 for the 2050 AD and a maximum value of 7.6 km2 for the 2100. Furthermore, according to the methodology proposed by Davidson-Arnott (2005), also the beach erosion was evaluated. The computations showed a potential mean landward retreat of the shoreline ranging from 19 to 93 m.

Abstract: The late Quaternary evolution of the Sele River coastal plain (Salerno Gulf, southern Italy) was investigated through integrated stratigraphical, chronological and palaeoecological analyses. The main environmental changes were ascribed to glacio-eustatic variations leading to rapid ingressions alternating with coastal progradations. The marked marine ingression of MIS 5.5 is testified by palaeoridges now cropping out 4 km inland at 11/13 m a.s.l. (Gromola palaeoridge). The eustatic minimum of MIS 2 is testified by lower shoreface deposits in the offshore core record and in the seismic profiles at 120/130 m below sea level. This prolonged sea-level fall was interrupted by at least three rapid sea-level rises, probably related to MIS 5.3, 5.1 and 3. The evidence of the first two sea level rises are represented by shoreface deposits in the inland S1 core (30 m thick, 3 m a.s.l., 1.5 km inland). The highstand of MIS 3 was identified by seismic profiles as onlapping marine deposits. The shore deposits at 100 m b.s.l were tentatively attributed to the lowstand of MIS 4. After the lowstand of MIS 2, the Sele Plain was newly flooded due to the rapid Post Glacial sea-level rise. This ingression caused the inland migration of a barrier-lagoon system and stopped at approximately 5.5 ky BP. From that moment the shoreline started prograding up to the present position probably due to the decrease in the sea-level rise rates and to the volcaniclastic supplies from the Neapolitan volcanoes, especially from the AD 79 Vesuvius eruption, also recorded in the subbottom chirp profiles.