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Five cores from the southern Tyrrhenian and Ionian seas were studied for their tephra and cryptotephra content in the 4.4–2.0 ka time interval. The chronological framework for each core was obtained by accelerator mass spectrometry14C dating, the occurrence of distinct marker tephra and stratigraphic correlation with adjacent records. Tephrochronology allowed us to correlate the analyzed deposits with tephra markers associated with Somma‐Vesuvius (79ad), Ischia Island (Cretaio), Mt Etna (FG, FL and FS) and Campi Flegrei (Astroni‐Agnano Monte Spina) events. For the first time in the marine setting, a large single glass data set is provided for the Late Holocene Etnean marker beds including the FS tephra (ca. 4.3 ka). Moreover, unknown deposits from Lipari (ca. 2.2–2.0 ka) and Vulcano (3.6–3.3 ka) are also recognized at more distal sites than previously reported. These results contribute to improve the high‐resolution tephrostratigraphic framework of the central Mediterranean Sea. They also provide new insights into the chemical composition and dispersal pattern of tephras that can be used as inter‐archive tools for regional and ‘local’ stratigraphic correlations and for addressing paleoclimate research.

Seismic stratigraphic analysis of very high-resolution single channel reflection seismic profiles provided insights into the last ~10 ka vertical deformation pattern in the submerged part of the Campi Flegrei resurgent caldera, off the Pozzuoli Bay. The collapse of the central part of the Campi Flegrei is associated with the eruption of the Neapolitan Yellow Tuff (NYT) at ~15 ka BP, and was followed by discrete phases of intracaldera volcanic activity and resurgence (Di Vito et al., 1999). Only in recent years the southern part of the caldera, presently submerged off the Pozzuoli Bay, has been explored using marine geophysical data (Sacchi et al., 2014; Steinmann et al., 2016). Interpretation of the high-resolution seismic reflection dataset acquired during the Cruise SEISTEC_2013, calibrated by marine gravity cores, allowed us to identify key horizons between the 1538 AD M. Nuovo and the ~3.7 ka Averno eruptions. Chronostratigraphy of the older part of the caldera fill was inferred through tentative correlation with significant eruptions known onland. Seismic stratigraphic interpretation reveals the occurrence during the last ~10 ka of at least three generations of Prograding Wedges (PW1-PW3) that were likely associated with corresponding periods of relative sea-level stands, and of minor coastal terraces. Correction of the observed depth of each sea-level indicator for the paleobathymetric estimate and for the glacio-hydro-isostatic sea-level change occurred since its formation, allowed to reconstruct differential relative sea-level curves for the western, central and eastern sector of the submerged part of the caldera. Preliminary results indicate that the periods of relative sea-level and accommodation space stability that allowed the onset of Prograding Wedges were attained when uplift occurred at a rate comparable to the rate of sea-level rise. These periods ostensibly correspond to known different phases of volcanic activity and unrest, suggesting that not only volcanism but also ground deformation were temporally clustered. Subsidence prevailed during periods of volcanic quiescence.

The Campi Flegrei and its offshore prolongation (Pozzuoli Bay) are a volcanic area dominated by a collapse caldera associated with the Neapolitan Yellow Tuff (NYT) eruption, occurred at ~15 ka BP, and by an intra-caldera resurgent dome. We present new insights into: a) the geometry and kinematics of faults formed inside the caldera, b) the architecture of the resurgent dome, and c) the relationship between the structural elements of the resurgent dome and ground deformations. This work is based on the integration of high- and ultra-high resolution seismic data, swath bathymetry data and ground deformation maps. The main results highlight that the NYT caldera, offshore, is characterized by an ellipsoidal shape, elongated towards the ESE direction, with axes of ~8 km and ~7 km. It is bounded by a ~6 km long and 1–2 km wide ring fault zone (RFZ) mainly consisting of an inward-dipping normal fault system and antithetic, outwarddipping, faults. The sedimentary fill of the caldera is up to 60 m thick, and can be divided into six units, characterized by different seismic facies, composition and depositional process.The inner-caldera resurgent dome, ~ 5 km in diameter, is limited by inner boundary of RFZ and consists in a broad antiformal structure with brittle deformation localized in an apical graben. The base of the resurgence corresponds to the thalweg of the Epitaffio valley in the western sector of the Pozzuoli Bay and the Bagnoli valley in the eastern one. The maximum cumulative uplift of the resurgent dome is ~180 m while its average uplift rate is ~ 9–12 mm/year, between 15.0–6.6 ka BP. A subsidence of ~10 m is suggested by the drowning of the infralittoral prograding wedge below the present-day storm wave base for the last 2 ka.The deformation velocity pattern of the Campi Flegrei displays a radial symmetry centered on the Pozzuoli harbor. It is possible to distinguish three almost-concentric sectors namely S1, S2, S3 with decreasing velocity from S1 (13-32 mm/year) to S3 (0.3-7.7 mm/year). The highest value (26-32 mm/year) is recorded at the Pozzuoli harbor. Sector S1 is bounded by a NE– SW-trending fault to the west and NW–SE faults to the east. The data suggests that this sector coincides with the resurgent dome of NYT caldera. The base of the latter corresponds to the faults bordering sector S1, and it can be correlated with the base of the resurgence recognized offshore. Sector S2 represents a narrow strip located between the base of the resurgence and the onland prolongation of the inner boundary of the RFZ.The results of our research provide new insights into the stratigraphic architecture and the shallow structure of the NYT collapse-caldera in the Pozzuoli Bay. Furthermore, they represent a base to reconstruct the entire onshore-offshore geometry of the inner-caldera resurgence and infer new constraints on the dynamics of the fluid flow system and magma source at depth.

The Neapolitan Yellow Tuff (NYT) caldera-forming eruption (ca. 15 ka; Deino et al., 2004) is a large event occurred at Phlegraean Fields during the late Pleistocene-Holocene. It produced a widespread isochron marker which links marine and terrestrial archives of the central Mediterranean area and northern Europe. In this research we describe the stratigraphic signature of the NYT deposits in the Late Pleistocene-Holocene shelf sequence of the Gulf of Gaeta (northern Campania region, southern Tyrrhenian sea) by using a number of gravity cores along with a grid of seismic lines that include Subbottom Chirp, Sparker 1kJ and Uniboom profiles. The Gulf of Gaeta represents the northern Campania continental margin that is part of a large extensional Plio-Pleistocene basin associated with normal and strike-slip faults linked to the evolution of the eastern Tyrrhenian Sea margin. Since mid-late Pleistocene, extensional tectonics took place across the continental margin and it was accompanied by intense volcanism, from several districts of which the Phlegraean Fields activity has greatly influenced the sedimentation in this sector. The continental shelf, gently sloping seaward, is as wide as 30 km in front of the Garigliano river and narrows southward reaching its minimum width of ca. 10 km seaward of Cuma; the shelf break is located between 120 m and 125 m depth. The upper Pleistocene-Holocene stratigraphic architecture of the continental shelf is characterized by an offlap prograding succession followed by a very thick transgressive onlapping unit and by the upper highstand unit mainly characterized in the southern sector by undulations probably linked to gas prone sediment. The slope is characterized by a uniform profile and, in the southern sector, it is incised by several submarine gullies. According to Chiocci and Casalbore (2011), the high thickness of sediment on the shelf and slope area was influenced by hyperpycnal flows, linked to the sudden and large supply of pyroclastic and volcaniclastic deposits in the Volturno river catchment basin. In the studied seismic sections, the NYT matches a highly continuous and parallel reflector which is interbedded within the transgressive systems tract deposits. The deposit was recovered in cores raised from the slope, where it is present few milliseconds below the sea floor, while on the shelf where it is located at higher depths, ranging from 10 to 30 ms (8 to about 25 m) below sea floor, has been mapped out through the seismic lines.. The tephrostratigraphic analysis allowed to characterize the NYT in terms of lithology and chemistry and to provide new insights into the depositional mechanisms in the marine environment.

Resurgent calderas are among the largest and most dynamic volcanic structures on earth. They are typically associated with major eruptions with considerable volumes of pyroclastic deposits accompanied by large collapse structures and late stage deformation and uplift of the intra-caldera floor region. The Campi Flegrei is a vast volcanic area located on the coastal zone of the Campania region of SW Italy, a large part of which develops off the Naples (Pozzuoli) Bay. The area has been active since at least ~80 ka BP and is structurally dominated by a caldera collapse, ca. 8 km in diameter, associated with the eruption of the Neapolitan Yellow Tuff (NYT), a 30–50 km3 Dense Rock Equivalent ignimbrite dated at ca. 15 ka BP. In the past decades the shallow crustal structure of the NYT caldera has been mostly reconstructed using gravimetric and magnetic data, seismic tomography images and modelling (analogue) experiments, whereas, the structural elements of the caldera collapse in the Pozzuoli Bay have been largely inferred, based on seafloor morphology and associated deposits. Despite the conspicuous research so far conducted off the Campi Flegrei, the stratigraphic architecture of the NYT caldera structure and inner caldera deposits is still poorly understood. This is mostly because of the intrinsic limitations due to the insufficient resolution of previous seismic datasets, as well as to the lack of reliable geologic calibration of the offshore geophysical data. In this study we present a detailed structural and stratigraphic reconstruction of the submerged part of the NYT caldera obtained by full integration of swath bathymetry, high-resolution multichannel and single channel reflection seismics, gravity core, geochemical analysis of marine fluid vents and seafloor temperature profiling, recently acquired from the Pozzuoli Bay, along with existing geological, geophysical and geodetic datasets on land. Particularly, the high-resolution reflection seismic data offer unprecedented detailed insights into the stratigraphy and shallow structure of the NYT caldera collapse–ring fault zone–inner resurgence system. The results of this research provide a contribution to the understanding of structural style and timing of deformation of restless, resurgent calderas that develop along active continental margins.

Shallow-water contourite drifts are sediments deposited in the water depth range where bottom currents may reflect not only basin-scale thermohaline circulation but also local processes that can be controlled by sea-level changes and morpho-bathymetry. We investigate these processes in the Gulf of Taranto (Ionian Sea) by integrating high-resolution reflection seismics, morpho-bathymetry data, and gravity core data with Coastal Modeling System Wave and CMS-M2D numerical models. Both geophysical-geological data and numerical modeling coherently indicate that Latest Quaternary shallow-water contourite drifts formed in the NW sector of the gulf in response to the eustatic fall of the sea-level that induced a severe impact on the bottom current system. The sea level drop caused subaerial exposure of the summit of the Amendolara Ridge that formed an island off the eastern coasts of Calabria and also created a narrow passageway between the island themselves and the northern Calabria coastline. Stratigraphic data indicate that the contourite drifts are bounded at the bottom and at the top by two major unconformities, and show that the sediments drifts formed between the onset of the last interglacial and the Early Holocene (~ 11.500 years BP). The analysis of the stratal architecture allows for the recognition of various contourite facies assemblages, depending on the local sea floor morphology, bottom currents and water depth. These are mostly represented by: a) Drift complex, along incision to the NE of the Amendolara Bank; b) Sheeted drifts, along the northeastern slope of the Amendolara Bank; c) Elongate drift along the northern Calabria continental shelf and upper slope. Numerical models predict that during the LGM the wave induced currents flow is driven roughly parallel to the northern Calabria paleo-coastline and counterclockwise around the north-eastern flank of the Amendolara Bank. The wave-induced hydrodynamics reaches the maximum velocity of ~ 0.1 m/s. According to Shields diagram, the minimum value of the flow velocity which allows the sediments to be mobilized is approximately 0.8 m/s for the considered grain sizes. Therefore, the additional contribution of the wave-induced hydrodynamics at the basin-scale thermohaline circulation of low Adriatic and Ionian created favorable conditions for the occurrence of the contourite drifts. Local erosional features coupled with a substantial lack of contourite deposits is also observed, until the present-day, on the south-eastern flank of the Amendolara Bank, where the LIW flows from the central Ionian Sea towards the Gulf of Taranto.

In this study we integrate high-resolution swath bathymetry, single-channel reflection seismic data and gravity core data, to provide new insights into the shallow structure and latest Quaternary to Holocene evolution of the submerged sector of the Neapolitan Yellow Tuff (NYT) caldera (Campi Flegrei) in the Pozzuoli Bay. The new data allow for a reconstruction of the offshore geometry of the NYT caldera collapse – ring fault system, along with the style and timing of deformation of the inner caldera resurgence. Our interpretation shows that the NYT eruption (~15 ka BP) was associated with a caldera collapse bounded by an inward-dipping ring fault system. The ring fault system consists in a 1-2 km wide fault zone that encircles an inner caldera region ~ 5 km in diameter and is often marked by the occurrence of pore fluids ascending through the fault zone, up to the seafloor, particularly in the western sector of the bay. A shallow magmatic intrusion along the ring fault zone was also detected offshore Bagnoli in the eastern part of the Pozzuoli Bay (Sacchi et al., 2014). Following the NYT eruption, the inner caldera region underwent significant deformation and resurgence with a maximum cumulative uplift of the offshore structure in the order of 180 m. The net uplift rate of the caldera resurgent dome was ~ 9 - 12 mm/year during the period 15.0 – 6.6 ka BP. The style of deformation of the resurgent structure can be described in terms of a broad doming, accompanied by subordinate brittle deformation, mostly concentrated in a small apical graben at the summit of the resurgent dome (Cole et al., 2005). Chronostratigraphic calibration of seismic profiles obtained by three tephra layers cored in the Pozzuoli Bay indicates 5 to 25 m of post-Roman differential subsidence and tilting towards ESE of the inner caldera resurgence, as recorded by the drowning of the infralittoral prograding wedge below the present-day storm wave base.

I Campi Flegrei rappresentano un distretto vulcanico attivo che si sviluppa al confine tra il settore emerso e sommerso del margine continentale campano. Il distretto vulcanico occupa una superficie di circa 200 km2, è strutturalmente dominato da una caldera di collasso del diametro di circa 8 km formatasi in seguito all’eruzione del Tufo Giallo Napoletano (TGN), un deposito ignimbritico del volume di 30-50 km3 Dense Rock Equivalent, datato a 15 ka B.P. circa, ed è attivo da almeno 78 ka B.P circa. L’obiettivo di questo lavoro è di ricostruire l’architettura stratigrafica e l’evoluzione vulcanotettonica tardo-Quaternaria del sistema caldera di collasso - faglia anulare - risorgenza intra-calderica del settore sommerso della caldera del TGN. A tal fine è stata analizzata una fitta maglia di profili sismici a riflessione monocanale di alta (Sparker) ed altissima (Subbottom Chirp) risoluzione. I dati sismici sono stati successivamente integrati sia con quelli ottenuti dall’analisi di carotaggi a gravità e batimetrici multibeam che con quelli disponibili in letteratura e, nell’insieme, analizzati in ambiente GIS. I nuovi dati indicano che il settore interno dell’area collassata a seguito dell’eruzione del TGN evolve inizialmente in condizioni di mare basso. L’area intra-calderica viene successivamente interessata dalla formazione di una struttura antiforme (risorgenza intra-calderica) il cui tasso di sollevamento è stato comparabile con l’innalzamento eustatico nell’intervallo Pleistocene superiore – Olocene [Lambeck et al., 2011]. A circa 10 ka B.P. il settore centrale della struttura risorgente raggiunge l’esposizione subaerea (terrazzo morfologico de “La Starza”). La calibrazione dei profili sismici Chirp con markers tefro-stratigrafici riconosciuti in un carotaggio e datati al 1538 A.D., 79 A.D. indica l’instaurarsi di un periodo di subsidenza in epoca post-Romana, registrato dall’annegamento di 10-25 m del cuneo di progradazione infralittorale rispetto alle profondità di equilibrio funzionale attualmente segnalate in area Mediterranea. L’interpretazione sismostratigrafica rivela, inoltre, la presenza di fluidi che risalgono attraverso la zona di faglia anulare che delimita la caldera del TGN. Bibliografia Lambeck, K., Antonioli, F., Anzidei, M., Ferranti, L., Leoni, G., Scicchitano, G., Silenzi, S., (2011). Sea level change along the Italian coast during the holocene and projections for the future. Quaternary International, 232, 250-257.

A detailed tephrochronological study was carried out on the deep-sea core collected from Site 963A in the Sicily Channel during ODP Leg 160. The chronology of the succession is provided by an age–depth model based on isotope stratigraphy and quantitative eco-biostratigraphy. Major, trace and rare earth element content was obtained on single glass grains through electron probe micro-analysis and laser ablation–inductively coupled plasma mass spectrometry techniques from six well-preserved tephra layers, characterized by a discrete thickness found along the succession. These deposits were correlated with the volcanic activity of Pantelleria and dated at 42.5, 127.5, 128.1, 129.1, 188.7 and 197.7 ka. This detailed chemical characterization of the studied deposits aims to provide a valuable reference database for scientists working on both proximal and distal products erupted at Pantelleria island during the Late Pleistocene. This study, moreover, offers the opportunity to better identify Pantelleria-related marker tephras within the tephrochronological framework of the central and eastern Mediterranean area.

Further 14C age constraints for the emplacement of historical and pre historical submarine debris avalanche and related to major collapses that affected the southern flank of Ischia island volcano are presented. Results are based on the stratigraphy of 11 gravity cores located in the southern offshore of the island and on new AMS analyses. The two collapsing events are: a) the Ischia submarine debris avalanche/debris flow, dated between ∼2.3 cal ka B.P. and ∼3 cal ka B.P.; b) a debris flow older than 23 cal ka B.P.. The Ischia debris avalanche, previously recognised mostly through marine geophysics, has an estimated volume of 1.5 km 3 and incorporates thousands of blocks that are still detectable over the sea-floor until 45-50 km from the island. Our results indicate an age of emplacement younger than previously held and support the still tentative hypothesis that a major catastrophic event occurred when the island was already inhabited by Greek settlers i.e. after the 7 th century b.C. The occurrence of at least two major collapsing events in the past 23 ka confirms the close genetic relationship between gravity failures and Mt. Epomeo uplift.

A high-resolution (IKB-Seistec) seismic survey calibrated with gravity-core data, off the Amalfi coast, a rocky coastal area on the southern side of the Sorrento Peninsula (Italy), documents the internal stratigraphic architecture of a series of small fan-deltas that develop at the mouth of major bedrock streams. The fan-delta system mostly postdates the Plinian eruption of Vesuvius of AD 79 and displays various phases of development associated with periods of high sediment supply from the adjacent river basins. During these periods landscape-mantling loose pyroclastic deposits (mostly air-fall tephra from Vesuvius) were quickly eroded and delivered to the continental shelf by sheet wash and flash flood events. Depositional processes on the foresets were dominated by sediment gravity flows originating from hyperpycnal river flow and pyroclastic fall deposits. This in turn created favourable conditions for sea-floor instability, soft sediment failure, slumping and sliding, which characterize the deltaic stratigraphic architecture. The intermittently increased sediment yield during the various phases of the evolution of the fan-delta system was probably influenced also by the morphoclimatic regime. This may have resulted in varying rates of progradation of the delta foresets, tentatively correlated with the main climatic oscillations of the last 2000 years. The Amalfi fan-delta system represents a small-scale analogue for larger flood-dominated fan-deltas of the world and may be regarded as a useful example for a better understanding of inner-shelf, mixed siliciclastic-volcaniclastic fan-delta systems in the stratigraphic record. © The Geological Society of London 2009.

This study on terrestrial and marine successions increases the understanding of the Late-Holocene volcanological and stratigraphical evolution of the south-western part of Campi Flegrei caldera. Stratigraphic data derived from field studies of two major tuff vents located along the coastal zone, namely Porto Miseno and Capo Miseno, clearly indicate that the Porto Miseno tuff ring slightly predates the Capo Miseno tuff cone. 40Ar/39Ar step-heating experiments, carried out on fresh sanidine separates from pumice samples, yielded a plateau age of 5090±140 yr BP for Capo Miseno and 6490±510 yr BP for Porto Miseno vent, thus confirming field observations. The volcanoclastic input derived from this recent and intense eruptive activity played a major role in the inner-shelf stratigraphic evolution of the Porto Miseno Bay deposits that have been drilled up to 40 m depth off the crater rim. The cored succession is characterised by transgressive marine deposits (mostly volcanic sand) with two intercalated peat layers (t1 and t2), dated at 3560±40 yr BP and 7815±55 yr BP (14C), respectively, interbedded with a 1-5 m thick pumice layer (tephra C). Peat layers have been chronostratigraphically correlated with two widespread paleosols onland while petrochemical analyses allowed us to correlate tephra C with the Capo Miseno tuff cone deposits. The results presented in this study imply a Late-Holocene volcanic activity that is also well preserved in the marine record in this sector of the caldera where a new chronostratigraphic reconstruction of the eruptive events is required in order to better evaluate the hazard assessment of the area.

Together, piston cores C1067, C1201 and C1202 from the continental shelf and slope in the Salerno Gulf and Cilento offshore in the Eastern Tyrrhenian Sea record long-term change (Paleomagnetic Secular Variation - PSV) of Earth's magnetic field during the last approximately 115,000 years. Each core contains the last 24,000 years except for the interval from about 20,000 to 11, 000 years that is absent in C1067 and C1202 because of erosion on the continental slope. The PSV for the Eastern Tyrrhenian Sea is correlated to curves of global relative paleomagnetic field intensity in other marine cores (Stoner et al., 2002) and dated lacustrine records of PSV for western Europe (Thouveny et al., 1990) and Great Britain (Turner and Thompson, 1981). Tephrochronology and radiometric dates (C14 and Ar/Ar) also are used for assigning an age to the record. Along with an improved record of PSV for the Mediterranean region, the PSV in the Salerno Gulf and Cilento offshore piston cores has application for placing time constraints on the marine geology and stratigraphy on the continental shelf and slope. The result is that catastrophic events such as large-scale submarine slumps, volcanic eruptions, turbidite deposition, and abrupt changes in sedimentation rate are dated. The changes in sedimentation rate seem to be linked to global rapid sea level pulses and climate events that induced concurrent reduction and/or abundance in the sediment supply from the adjacent coastal margin.

This study on terrestrial and marine successions increases the understanding of the Late-Holocene volcanological and stratigraphical evolution of the south-western part of Campi Flegrei caldera that has been previously reported quiescent during the last 10,000 years. Stratigraphic data derived from field studies of two major tuff vents located along the coastal zone, namely Porto Miseno and Capo Miseno, clearly indicate that the Porto Miseno tuff ring slightly predates the Capo Miseno tuff cone. 40Ar/39Ar step-heating experiments, carried out on fresh sanidine separates from pumice samples, yielded a plateau age of 5090 +/- 140 yr BP for Capo Miseno and 6490 +/- 510 yr BP for Porto Miseno vent, thus confirming field observations. The volcanoclastic input derived from this recent and intense eruptive activity played a major role in the inner-shelf stratigraphic evolution of the Porto Miseno Bay deposits that have been drilled up to 40 m depth off the crater rim. The cored succession is characterised by transgressive marine deposits (mostly volcanic sand) with two intercalated peat layers (t1 and t2), dated at 3560 +/- 40 yr BP and 7815 +/- 55 yr BP (14C), respectively, interbedded with a 1-5 m thick pumice layer (tephra C). Peat layers have been chronostratigraphically correlated with two widespread paleosols onland while petrochemical analyses allowed us to correlate tephra C with the Capo Miseno tuff cone deposits. The results presented in this study imply a Late-Holocene volcanic activity that is also well preserved in the marine record in this sector of the caldera where a new chronostratigraphic reconstruction of the eruptive events is required in order to better evaluate the hazard assessment of the area.

An extensive, high-resolution bathymetric survey has recently been carried out, portraying the continental shelf-slope system of the Campania Region, in southern Italy (Eastern Tyrrhenian Sea). The relative bathymetric data were acquired between 1997 and 2002, using multibeam systems with an average vertical resolution of < 0.25 % water depth and a position accuracy of < 10 m. The survey data were successively merged with a Digital Terrain Model (DTM) created from topographic maps of the onshore coastal area and islands of theNaples Bay, to produce a Digital Elevation Model (DEM) based on a homogeneous grid with cell-spacing of 20 m. The shaded-relief, colour scale map of the Naples Bay presented in this study provides new, detailed information on the morphology of the coastal Campania Region. This continental margin displays evidence of the interplay between tectonics and volcanism and their interference with sedimentary processes during the latest Neogene and Quaternary. The major morphological features revealed by the 3D digital maps are: 1) the system of marine canyons (Dohrn and Magnaghi) that cut the continental slope at a depth between 250 m and 1100 m; 2) the funnelshaped marine slope system of the Ischia volcanic structure; 3) the onshore-offshore volcanic field of the Campi Flegrei; 4) the rugged seafloor area (of a diameter of ca 2 km) off the town of Naples (Banco della Montagna), caused by active uplift of small-scale volcaniclastic diapirs (pyroclastic lumps); and 5) the debris-flow/avalanche deposits on the inner continental shelf of the Eastern Bay of Naples, that evolved from the pyroclastic products of the Vesuvius