Claudio Scarpati

... Isaia R, Orsi G, Southon J, de Vita S, D'Antonio M, Pappalardo L, Piochi M (1999) Volcanism and deformation since 12,000 years at the Campi Flegrei caldera (Italy). J Volcanol Geotherm Res 91:221–246 Fedele L, Insinga DD, Calvert AT, Morra V, Perrotta A, Scarpati C (2011 ...

The city of Naples can be considered part of the Campi Flegrei volcanic field, and deposits within the urban area record many autochthonous pre- to post-caldera eruptions. Age measurements were carried out using 40Ar–39Ar dating techniques on samples from small monogenetic vents and more widely distributed tephra layers. The 40Ar–39Ar ages on feldspar phenocrysts yielded ages of c. 16 ka and 22 ka for events older than the Neapolitan Yellow Tuff caldera-forming eruption (15 ka), and ages of c. 40 ka, 53 ka and 78 ka for events older than the Campanian Ignimbrite caldera-forming eruption (39 ka). The oldest age obtained is 18 ka older than previous dates for pyroclastic deposits cropping out along the northern rim of Campi Flegrei. The results of this study allow us to divide the Campi Flegrei volcanic history into four main, geochronologically distinct eruptive cycles. A new period, the Paleoflegrei, occurred before 74–78 ka and has been proposed to better discriminate the ancient v...

ABSTRACT Mount Etna dominates the landscape of northeast Sicily and is the largest continental volcano in the world: the summit crater reaches the height of about 3300 m above sea level, and its volcanic products cover an area of around 1750 km2. In Greek and Roman mythology Etna was famed as the forge of the fire God VOLCANUS and as the prison of the monster Typhon.

ABSTRACT The Phlegraean Fields, an active volcanic field located west of the city of NEAPOLIS (NAPLES), has been the site of numerous eruptions from monogenic volcanoes for the past 70,000 years. Some of these volcanoes are famous from an historical point of view, including the volcano of CUMAE (KYME) that was the place of the first Greek colony on the mainland of Italy in the eighth century BCE and the Capo Miseno (MISENUM) volcano from which PLINY THE YOUNGER witnessed the eruption of VESUVIUS that in 79 CE destroyed the Roman cities of POMPEII and HERCULANEUM.

40Ar/ 39Ar ages have been measured on the older major explosive eruptions of Somma-Vesuvius volcano in Italy. These eruptions all have pumice fall, and pyroclastic surge and flow deposits. The eruptive history of Somma-Vesuvius volcano has previously been based on uncalibrated 14C ages, mostly on carbon from paleosols, reported by Delibrias and others (1979) and Sigurdsson and others (1985). These

Large ignimbrites are the product of devastating explosive eruptions that have repeatedly impacted climate and life on global scale. The assemblage of vertical and lateral lithofacies variations within an ignimbrite sheet, its internal architecture, may help to determine how the parental pyroclastic current evolves in time and space. The 39 ka Campanian Ignimbrite eruption, vented from Campi Flegrei caldera, laid down a thick ignimbrite over an area of thousands of km 2. A detailed reconstruction of the vertical and lateral variation of the seven lithofacies recognised in the ignimbrite medial sequence constrains the behaviour of this event. The pyroclastic current flowed over a wide area around Campi Flegrei without depositing (bypass zone), and inundated a huge area during most of the paroxysmal, waxing phase, emplacing a mainly incipiently-to strongly-welded ignimbrite. Following this waxing phase, the leading edge of the current retreated back towards the source as the current waned, impacting a progressively smaller area and leaving an unconsolidated ash and lapilli deposit, later lithified. Our study illustrates how large pyroclastic currents can evolve in time and space and the importance of both internal (eruptive and transport mechanisms) and external (topography, surficial water and rain) factors in governing their behaviour. Catastrophic pyroclastic currents impact huge regions and represent one of the most devastating natural phenomena 1. Large pyroclastic currents emplace thick sequences of ash-and vesiculated juvenile-rich deposits (ignimbrite 2,3). Large ignimbrites show changes in facies on a regional scale 4. There are only a few large ignim-brites that have been subject to detailed studies of their three-dimensional facies architecture; these include the Bishop Tuff 5 , Taupo ignimbrite 6 , Novarupta ignimbrite 7 , Cerro Galán ignimbrite 8 , and Neapolitan Yellow Tuff 9. In order to broaden our understanding of these eruptive events, studies of additional, well-exposed examples are needed. Here, we present a detailed examination of the medial pyroclastic current deposits (10 to 80 km from source) of the Campanian Ignimbrite eruption (CI), a caldera-forming Plinian event occurred 39 ka ago 10,11 , whose pyroclastic current spread over a huge area from Campi Flegrei (Italy) emplacing a thick ignimbrite sequence (Figs. 1, 2). The estimated magnitude ranges between 7.2 and 7.7 12,13. We describe CI architecture (i.e. its distribution, thickness and vertical and lateral variations of lithofacies) and explore the role of eruptive and transport mechanisms as well as topography, weather, and surficial water as factors that influenced deposition from the pyroclastic current. Ignimbrites are considered to be emplaced by concentrated pyroclastic flows 19,20 or dilute and turbulent pyroclastic currents 21-23. Because of their complexity, the physics of these flows are still poorly understood. Experimental approaches 24-28 and numerical formulations 29,30 have been used to simulate transport and emplacement of this type of gravity current. Field and laboratory data allowed previous studies to conclude that the CI was deposited from a dilute pyroclastic current 31-33. We concur with these authors on the dilute nature of the CI transport system and use their conclusions as a starting point. In this paper, we integrate a model 33 addressing the turbulent and dilute nature of the CI pyroclastic current, during the emplacement of the CI ground layer, with new data (lithofacies and their grainsize characteristics) extending its application to the whole medial ignimbrite sequence. The study highlights how the CI ignimbrite sequence was assembled and the main internal and external factors that influenced its sedimentation, which can in turn help to constrain the general behaviour of large pyroclastic currents. OPEN

A new stratigraphic survey of the pyroclastic deposits blanketing Pompeii ruins shows departures from prior reconstruction of the events that occurred inside the town during the two main phases (pumice fallout and pyroclastic density currents) of the AD 79 Vesuvius eruption. We document the depth and distribution of subaerial erosion surfaces in the upper part of the pyroclastic sequence, formed during two short-lived breaks occurring in the course of the second phase of the eruption. These pauses could explain why 50% of the victims were found in the streets during the pyroclastic density currents phase.

Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an active, resurgent caldera. It has been traditionally interpreted as a nested caldera formed by collapses during the 100-200 km 3 Campanian Ignimbrite (CI) eruption at ∼ 39 ka and the 40 km 3 eruption of the Neapolitan Yellow Tuff (NYT) at ∼ 15 ka. Recent studies have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. Published by Copernicus Publications on behalf of the IODP and the ICDP. 2 M. Sacchi et al.: A roadmap for amphibious drilling at the Campi Flegrei caldera A MagellanPlus workshop was held in Naples, Italy, on 25-28 February 2017 to explore the potential of the CFc as target for an amphibious drilling project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is an ideal site to investigate the mechanisms of caldera formation and associated post-caldera dynamics and to analyze the still poorly understood interplay between hydrothermal and magmatic processes. A coordinated onshore-offshore drilling strategy has been developed to reconstruct the structure and evolution of Campi Flegrei and to investigate volcanic precursors by examining (a) the succession of volcanic and hydrothermal products and related processes, (b) the inner structure of the caldera resurgence, (c) the physical, chemical, and biological characteristics of the hydrothermal system and offshore sediments, and (d) the geological expression of the phreatic and hydro-magmatic eruptions, hydrothermal degassing, sedimentary structures, and other records of these phenomena. The deployment of a multiparametric in situ monitoring system at depth will enable near-real-time tracking of changes in the magma reservoir and hydrothermal system.

The products of explosive activity of La Soufrière volcano on the island of St Vincent over the last 1000 years are described. Dates for the different eruptions were determined using information from contemporary accounts, fieldwork and radiocarbon dating. Scoria-flow type pyroclastic density currents (PDCs) dominate the products of both the historical eruptions (1979, 1902-03, 1718/1812 CE) and prehistoric eruptions (~1580 and 1440 CE) with subordinate fallout components associated with several eruptions. Radiocarbon dating shows that these six eruptions define a crude cyclicity with repose periods ranging between 77 and ~140 years and systematically decreasing in more recent times. Two prehistoric eruptions, in ~1440 and 1580 CE respectively, both produced magmatic lapilli fallout and PDCs, and were fed by slightly more evolved magmas than the historical eruptions. The eruptions in 1902 and 1812 CE had ash-rich, possible phreatomagmatic activity at their onset. The iconic 1902-03 CE eruption generated radial distributed PDCs, which were responsible for the deaths of ~1500 people. However, only small remnants of these deposits remain and the original distribution cannot be determined from the preserved geology, which has important implications for hazard studies. Petrochemical work has shown that magmas involved in the explosive eruptions were quite narrow in compo-sitional range, mainly comprising basaltic andesites. The 1902-03 eruption involved a late stage basaltic component in March 1903. However, activity in the last 1000 years generated notably more homogeneous magmas with a narrower range than the older eruptive periods previously reported in the literature, suggesting a significant variation in the magmatic reservoir feeding system with time.

Pre-caldera (> 22 ka) lateral activity at Somma-Vesuvius is related to scoria-and spatter-cone forming events of monogenetic or polygenetic nature. A new stratigraphic, sedimentological, textural and lithofacies investigation was performed on five parasitic cones (Pollena cones, Traianello cone, S. Maria a Castello cone and the recently found Terzigno cone) occurring below the Pomici di Base (22 ka) Plinian products emplaced during the first cal-dera collapse at Somma-Vesuvius. A new Ar/Ar age of 23.6 ± 0.3 ka obtained for the Traianello cone as well as the absence of a paleosol or reworked material between the S. Maria a Castello cone and the Pomici di Base deposits suggest that such cone-forming eruptions occurred near the upper limit of the pre-caldera period (22–39 ky). The stratigraphy of three of these eccentric cones (Pollena cones and Traianello cone) exhibits erosion surfaces, exotic tephras, volcaniclastic layers, paleosols, unconformity and paraconformity between superimposed eruptive units revealing their multi-phase, polygenetic evolution related to activation of separate vents and periods of quies-cence. Such eccentric cones have been described as composed of scoria deposits and pure effusive lavas by previous authors. Lavas are here re-interpreted as welded horizons (lava-like) composed of coalesced spatter fragments whose pyroclastic nature is locally revealed by relicts of original fragments and remnants of clast outlines. These welded horizons show, locally, rheomorphic structures allowing to define them as emplaced as clastogenic lava flows. The lava-like facies is transitional, upward and downward, to less welded facies composed of agglutinated to unwelded spatter horizons in which clasts outlines are increasingly discernible. Such textural characteristics and facies variation are consistent with a continuous fall deposition of Hawaiian fire-fountains episodes alternated with Strombolian phases emplacing loose scoria deposits. High enrichment factor values, measured in the scoria deposits, imply the ejection of large proportion of ash even during Strombolian events.

The Campanian Ignimbrite eruption (39 ka) was the most powerful eruptive event of the Campi Flegrei caldera (southern Italy). This event coincided with the onset of a cold climatic phase and the Paleolithic transition from Neanderthals to modern humans. The eruption started with a sustained column that emplaced a widespread pyroclastic fall deposit covering an area >4000 km 2 within the 15 cm isopach. For the first time, we present the complete longitudinal variation from the coarse and 10-m-thick proximal (down to 15 km) sequence, through the well-stratified pumice lapilli deposit in medial areas (30–80 km), to the distal tephra (hundreds to thousands of kilometers distant). The Plin-ian pumice fall deposit shows a strong lateral heterogeneity due to variations in stratifica-tion, grading, and abundance of components. All Campanian Ignimbrite fall layers display Plinian dispersal. Variation of grain size with stratigraphic height suggests that the convec-tive plume was far from steady state. Initially, the plume dispersed 1.3 km 3 of tephra toward the ENE (N75°E) from a height of 29 km (layer A). A gradual increase in intensity resulted in inverse grading of layer B. Column height increased from 26 to 37 km at a vertical velocity of 3.6 m/s. It had a main dispersal axis to the east (N97°E) and a secondary lobe to the southeast (N137°E). During this phase, a maximum volume of 1.73 km 3 of tephra was emplaced. Accessory lithics concentrated in layer C are possibly due to vent clearing after partial blockage of the vent. The 33-km-high column dispersed ejecta to the east (N95°E), with only 0.2 km 3 of tephra erupted during this phase. During the successive gradual decline in eruption intensity (column height decreased from 38 to 32 km at a velocity of 4.2 m/s), a normally graded layer (D) with a volume of 1 km 3 accumulated to the east (N95°E). The sustained column phase ended with a pulsating and partially collapsing column that reached 23 km in height and dispersed 1.1 km 3 of a stratified and lithic-rich succession (layer E) to the southeast (N112°E). If we include the distal co-Plinian deposit, a total volume of 7.8 km 3 (dense rock equivalent [DRE]) of magma was released (containing 0.09 km 3 of accessory lithics). Tephra mass for the single layers is on the order of 10 11 kg, and the total mass is ~2 × 10 12 kg (2 × 10 13 kg including the co-Plinian ash). Mass discharge rates ranged from 0.9 to 6.7 × 10 8 kg/s. The calculated magnitude of the sustained column phase is 6.3. The duration of the Plinian phase of this eruption, based on the ratio of two param eters, erupted mass divided by discharge rate, is estimated to have been ~20 h (including co-Plinian ash). This study shows that Plinian deposits are not always homogeneous and, as for pyro-clastic current deposits, can show an articulate architecture. Only the complete reconstruction of vertical and lateral variations in components, stratification, and grading might provide insights into the temporal and spatial evolution of the sustained plume.

The proximal Plinian fall deposits of the Campanian Ignimbrite (CI; 38 ky, Fedele et al., 2008) and Pomici di Base (PdB; 18 ky, Bertagnini et al., 1998) have been investigated in order to understand the contribution of each part of the plume to the proximal sedimentation. Following Houghton et al. (2004b) we consider three main transport regimes: jet phase (producing facies Fb), buoyant region of the plume (producing facies Fa) and direct lateral ejection (producing facies Fc).

As well documented in medial locations (Sparks et al., 1992, 1997; Ernst et al., 1996), transport regimes can develop different facies even in proximal locations according to the dynamics of the eruptive column. Our proximal deposits show stratification and diffuse bedding allowing us to introduce two new facies: stratified Fa (sFa) and diffuse bedded Fb (dbFb). These facies retain the transport regime previously proposed for Fa (buoyant plume) and Fb (jet phase) but their lithological features are influenced by near-vent depositional conditions.

Lithology and sedimentological data (grain-size, componentry, maximum clasts) suggest that most of the sedimentation occurred mainly from the buoyant plume with simultaneous contribution from the other two different dynamic regimes. Coarse clasts falling from the lower margins of the plume strongly affected the sedimentation of the CI proximal fall deposit with a minor contribution from lithic clasts ballistically emplaced and partial collapses of the plume forming pyroclastic density currents. In contrast, the PdB proximal fall deposit was strongly affected by coarse clasts emplaced directly from the vent through parabolic trajectories, with very little contribution of material emplaced from the lower part of the plume. These differences can be attributed to different vent/conduit processes acting during the eruptions

A twenty years lasting geo-volcanological survey allowed us to reconstruct the eruptive history of the city of Naples which is part of the active Campi Flegrei (Phlegraean Fields) volcanic field. Naples hills are mainly modelled by volcanic and volcanotectonic processes, partly masked by historical floods that buried the lower part of the city as well as the main roman buildings. The ancient core of these hills is made by coalescent tuff cones and a lava dome older than 78 ka. Remnants of this ancient activity are draped by a thick succession of pyroclastic deposits comprising large, caldera-forming ignimbrites (Campanian Ignimbrite, 39 ka and Neapolitan Yellow Tuff, 15 ka), phlegraean tephra and monogenetic vents (e.g. Trentaremi and Nisida volcanoes). The western area of Naples collapsed during both the ignimbrite episodes. Caldera faults bound Camaldoli hill, San Martino hill, Capodimonte hill and Posillipo hill. Stratigraphical and geochronological data show that the volcanic activity in the city of Naples has lasted at least 78 ka and probably longer on the basis of the undated ancient tuffs at the base of the neapolitan succession. This persistent volcanic activity indicates that this urban sector of the Campi Flegrei volcanic field, could be considered as a likely eruption location for the next event

The Campanian Ignimbrite eruption (39 ka) is the most powerful caldera-forming event vented from Campi Flegrei. The pyroclastic density current (PDC) deposits associated to this plinian, high-magnitude event are mainly known as a widespread welded gray trachytic tuff containing inverse-graded scoria clasts. A new study of the lithological facies of the medial-distal CI PDC deposits has highlighted the occurrence of five different lithofacies: massive, stratified, sand-wave, inverse-graded, normal-graded. These lithofacies exhibit three main vertical association: stratified/sand-wave to massive, stratified to inverse/normal-graded, massive to inverse-graded. The facies associations reflect changing in style of deposition from the base of an “unsteady” pyroclastic density current.

The systematic excavation of the site of Guado San Nicola (Monteroduni, Molise) revealed a stratigraphic sequence, more than two meters thick, located on the distal part of an ancient terraced alluvial cone made by the Lorda creek, a tributary of the Volturno river.
The lithologic, morphographic and pedostratigraphic evidences suggest its attribution to an Interstadial
of MIS6 or to MIS 72. The radiometric dating (40Ar/39Ar method and Electron Spin Resonance in combination with the uranium family disequilibrium method) reported an age between 350 and400.000 years, confirmed by a Late Galerian fauna and by the presence of Cervus elaphus acoronatus and Equus ferus ssp.
The fauna assemblage, apart from these two taxa, is characterized by the presence of Ursus sp., Elephas sp., Stephanorhinus kirchbergensis, Bos primigenius e cf. Megacerinae, which denote a warm temperate dry climate. Paleontological remains are characterized by the presence of intentional fractures produced by human activities aimed at the extraction of bone marrow while cut marks are badly preserved. The abundance of deer antlers seems to be due to its use as soft hammers.
Handaxes of different forms and variable sizes are frequent, usually the shaping is mostly accurate on the point while the base is not shaped at all; the débitage component is  characterized by the presence of a Levallois production.
From a chronological point of view, despite the lithologic, morphographic and pedostratigraphic interpretation suggests a correlation to an Interstadial of MIS 6 or to MIS 7, the considerations on the fauna and radiometric dating are in agreement with an attribution to MIS 11.

Distribution of ignimbrites is controlled chiefly by preexisting topography forming thin veneer deposits on steepslope
relief and thicker, valley-ponding deposits in valley bottoms. The calculation of volumes of ignimbrites is difficult because of the nonlinear dependence of thickness with distance. Calculation using geometrical methods is reviewed and the uncertainty with each method is discussed. Based on the genetic relationship between vitricenriched, co-ignimbrite air-fall ashes and crystal-enriched ignimbrites, a newmethod is proposed to calculate ignimbrite volume. A simple equation can be used if the volume of the associate and co-genetic distal ash fall and the ignimbrite vitric loss are known. This simple relation is unaffected by deposit geometry, paleotopography irregularities and post-depositional compaction and erosion. The proposed methodology is used to reassess the controversial volume estimates of the Campanian Ignimbrite (Campi Flegrei, southern Italy). The revised volume
of the ignimbrite is 54 km3 (25 km3 DRE). The calculated magnitude of the collapsing phase (sum of the ignimbrite
mass and co-ignimbrite ash mass) is 7.2.

As a volcanologist who has spent the last twenty years studying Vesuvius and the impact of its historical and prehistoric destructive eruptions on perivolcanic areas and specifically on urban settlements, I was particularly interested in the chapter regarding the relationship between archaeology and geology and the contribution of volcanology to the reconstruction of the events that occurred during the AD 79 Vesuvius eruption.

"The city of Naples can be considered part of the Campi Flegrei volcanic field, and deposits within the urban area record many autochthonous pre- to post-caldera eruptions. Age measurements
were carried out using 40Ar–39Ar dating techniques on samples from small monogenetic vents and more widely distributed tephra layers. The 40Ar–39Ar ages on feldspar phenocrysts yielded ages of c. 16 ka and 22 ka for events older than the Neapolitan Yellow Tuff caldera-forming eruption (15 ka), and ages of c. 40 ka, 53 ka and 78 ka for events older than the Campanian Ignimbrite caldera-forming eruption (39 ka). The oldest age obtained is 18 ka older than previous dates for pyroclastic deposits cropping out along the northern rim of Campi Flegrei. The results of this study allow us to divide the Campi Flegrei volcanic history into four main, geochronologically distinct eruptive cycles. A new period, the Paleoflegrei, occurred before 74–78 ka and has been proposed to better discriminate the ancient volcanism in the volcanic field. The eruptive history of Campi Flegrei extends possibly further back than this, but the products of previous eruptions are difficult to date owing to the lack of fresh juvenile clasts. These new geochronological data, together with recently published ages related to young volcanic edifices located in the city of Naples (Nisida volcano, 3.9 ka) testify to persistent activity over a period of at least 80 ka, with an average eruption recurrence interval of ∼555 years within and adjacent to this densely populated city"

Industrial minerals represent an important resource for the Italian economy, both in terms of exploitation and transformation, especially in those sectors for which Italy holds a leadership such as ceramics and glass. Among Italian regions Campania is one of the poorest of such kind of resources although some geological
formations could be advantageously exploited. An important role is played by the deposits of sedimentary zeolites linked to the activity of different volcanic districts occurring on the Neapolitan territory such as the Campanian Ignimbrite, the most important volcanic episode of the Campi Flegrei (Southern Italy), which
blankets a wide area of the Campanian region. The Campanian Ignimbrite has been thoroughly investigated from a volcanological and petrographic point of view. However, little attention was devoted to the attainment of those information useful to verify the potential of the deposit as well as the interpretation of
post-depositional mineral-forming processes that have affected this deposit and have led to the formation of several facies, among which the most important are characterized by intense feldspathization (grey facies) and remarkable zeolitization (yellow facies). X-ray diffraction, X-ray fluorescence, inductively coupled plasma emission spectrometry and scanning electron microscopy methods were used to thoroughly characterize the entire set of samples collected from 31 outcrops. Data so far acquired enabled to define the role played by several parameters (i.e., temperature, alkaline and alkaline-earth cations, etc.) in influencing the zeolitization process and the consequent crystallization
of phillipsite, chabazite, and analcime. Feldspathization appears to have been controlled mainly by the emplacement temperature of the deposits.
The proposed genetic model involves emplacement of the pyroclastic flow in a single episode, producing a deposit with an upward-decreasing temperature gradient. In this model, the central portion had a temperature insufficient to cause significant feldspathization, and the upper portion of the formation was affected by water percolation while still hot, producing progressive zeolitization.
Volcano-stratigraphical parameters suggest some constrains on the maximum temperatures affecting the central portion of WGI.
Thermodynamic data on zeolites constrain the maximum  temperatures of the LYT unit which likely decrease upwards in the unit up to ambient conditions in CPF.

"The AD 472 eruption and its impact on some sites on the slopes of Vesuvius. This contribution provides a multi-disciplinary
analysis of the AD 472 eruption of Vesuvius in archaeological contexts. The first section overviews the settlement pattern and the data available on the sites buried by volcanoclastic fill. It further addresses the question of the exact number and main features
of the late antique eruptions of Vesuvius (i.e. AD 472, 505 and 512), it reviews the information from literary sources and analyses
the evidence from the field. In particular, the impact of the AD 472 eruption on two sites on the northern slopes of Vesuvius – in
Pollena Trocchia and Somma Vesuviana – is thoroughly described. The last section deals with the problem of resettlement after AD 472 and puts forward some hypotheses as to how the land recovered."

"Nel 2004 si è avviato un progetto di ricerca multidisciplinare, denominato Apolline, sotto gli auspici dell’università degli Studî Suor orsola benincasa di napoli e con la collaborazione di numerose università italiane e straniere. Obiettivo del progetto era lo studio sistematico delle evidenze archeologiche che insistono nel comune di Pollena trocchia, preso a campione per l’intera area nord-vesuviana. Dal 2006 é in corso il recupero e lo scavo integrale del sito in localita masseria De Carolis, che ha permesso finora di mettere in luce 10 ambienti di un complesso termale.
le strutture murarie finora individuate si fondano sopra i depositi cineritici dell’eruzione pliniana del 79 d.C. e sono interrate per due terzi dai flussi vulcanoclastici della l’eruzione subpliniana detta di Pollena (472 d.C.) e per il resto da un compatto deposito cineritico pertinente ad una delle eruzioni del breve ciclo tardoantico (505-512) e da successive eruzioni altomedievali."

Factors influencing the erosive behaviour of large pyroclastic density currents (PDCs), both mainly massive or thinly stratified, are poorly understood. To investigate about parameters influencing the erosive behaviour of PDCs produced during the flowing phase of large, caldera-forming, plinian (Campanian Ignimbrite) and phreatoplinian (Neapolitan Yellow Tuff) eruptions, we use scoured fall deposits at the base or interstratified with PDCs deposits from the Campanian region (Italy). At several localities, we calculate the depth of PDCs erosion by comparing the measured thickness of eroded remnants to reconstructed thickness at each site (estimated by isopachs mapping), as well as recording the: 1) distance from vent, 2) elevation of  the locality, and 3) paleoslopes. Furthermore, we have considered how these factors can be influenced by outcrops exposure. Depth of erosion correlates with distance from the vent in low-relief landscape, while across very rugged topography, the only related parameter is elevation. The different erosive patterns appear to show how pyroclastic currents interact with the topography in surrounding terrain. When a pyroclastic density current crosses relatively flat surfaces it decelerates away from the vent, decreasing its erosive capacity, but when moving through steep terrain, a pyroclastic density current accelerates down the valley, increasing its erosive capacity.

A granular multiphase model has been used to
evaluate the action of differently sized particles on the dynamics
of fountains and associated pyroclastic density currents.
The model takes into account the overall disequilibrium
conditions between a gas phase and several solid
phases, each characterized by its own physical properties.
The dynamics of the granular flows (fountains and pyroclastic
density currents) has been simulated by adopting a
Reynolds-averaged Navier-Stokes model for describing the
turbulence effects. Numerical simulations have been carried
out by using different values for the eruptive column temperature
at the vent, solid particle frictional concentration, turbulent
kinetic energy, and dissipation. The results obtained
provide evidence of the multiphase nature of the model and
describe several disequilibrium effects. The low concentration
(5×10−4) zones lie in the upper part of the granular
flow, above the fountain, and above the tail and body of pyroclastic
density current as thermal plumes. The high concentration
zones, on the contrary, lie in the fountain and at the
base of the current. Hence, pyroclastic density currents are
assimilated to granular flows constituted by a low concentration
suspension flowing above a high concentration basal
layer (boundary layer), from the proximal regions to the distal
ones. Interactions among the solid particles in the boundary
layer of the granular flow are controlled by collisions between
particles, whereas the dispersal of particles in the suspension
is determined by the dragging of the gas phase. The
simulations describe well the dynamics of a tractive boundary
layer leading to the formation of stratified facies during
Strombolian to Plinian eruptions.

We welcome the opportunity to discuss the results
presented in Fedele et al. (2011) further. We begin
addressing the criticisms of Isaia et al. (2011) regarding
our age determinations and then we clarify our ideas about
previous stratigraphic studies.

"The Campi Flegrei hosts numerous monogenetic
vents inferred to be younger than the 15 ka Neapolitan
Yellow Tuff. Sanidine crystals from the three young Campi
Flegrei vents of Fondi di Baia, Bacoli and Nisida were
dated using 40Ar/39Ar geochronology. These vents, together
with several other young edifices, occur roughly along the
inner border of the Campi Flegrei caldera, suggesting that
the volcanic conduits are controlled by caldera-bounding
faults. Plateau ages of ∼9.6 ka (Fondi di Baia), ∼8.6 ka
(Bacoli) and ∼3.9 ka (Nisida) indicate eruptive activity
during intervals previously interpreted as quiescent. A
critical revision, involving calendar age correction of
literature 14C data and available 40Ar/39Ar age data, is
presented. A new reference chronostratigraphic framework
for Holocene Phlegrean activity, which significantly differs
from the previously adopted ones, is proposed. This has
important implications for understanding the Campi Flegrei
eruptive history and, ultimately, for the evaluation of related
volcanic risk and hazard, for which the inferred history of
its recent activity is generally taken into account"

A quantitative and qualitative evaluation of the damage caused by the products of explosive eruptions to buildings provides an excellent contribution to the understanding of the various eruptive processes during such dramatic events. To this end, the impact of the products of the two main phases (pumice fallout and pyroclastic density currents) of the Vesuvius AD 79 explosive eruption onto the Pompeii buildings has been evaluated. Based on different sources of data, such as photographs and documents referring to the archaeological excavations of Pompeii, the stratigraphy of the pyroclastic deposits, and in situ inspection of the damage suffered by the buildings, the present study has enabled the reconstruction of the events that occurred inside the city when the eruption was in progress. In particular, we present new data related to the C.J. Polibius’ house, a large building located inside Pompeii. From a comparison of all of the above data sets, it has been possible to reconstruct, in considerable detail, the stratigraphy of the pyroclastic deposits accumulated in the city, to understand the direction of collapse of the destroyed walls, and to evaluate the stratigraphic level at which the walls collapsed. Finally, the distribution and style of the damage allow us to discuss how the emplacement mechanisms of the pyroclastic currents are influenced by their interaction with the
urban centre. All the data suggest that both structure and shape of the town buildings affected the transport and deposition of the erupted products. For instance, sloping roofs ‘drained’ a huge amount of fall pumice into the ‘impluvia’ (a rectangular basin in the centre of the hall with the function to collect the rain water coming from a hole in the centre of the roof), thus producing anomalous deposit thicknesses. On the other hand, flat and low-sloping roofs collapsed under the weight of the pyroclastic material produced during the first phase of the eruption (pumice fall). In addition, it is evident that the walls that happened to be parallel to the direction of the pyroclastic density currents produced during the second eruptive phase were minimally damaged in comparison to those walls oriented perpendicular to the flow direction. We suggest that the lower depositional parts of the pyroclastic currents were partially blocked (locally reflected) and slowed down because of recurring encounters with the closely spaced walls within buildings. Locally, the percentage of demolished walls decreases down-current, which has been interpreted as a loss in kinetic energy within the depositional system of the flow. However, it seems that the upper transport system by-passed these obstacles, then supplied new pyroclasts to the depositional system that restored its physical characteristics and restored enough kinetic energy to demolish the next walls and buildings further along its path.

Detailed descriptions of the effects of explosive eruptions on urban settlements available to volcanologists are relatively rare. Apart from disease and starvation, the largest number of human deaths caused by explosive eruptions in the twentieth century are due to pyroclastic flows. The relationship between the number of victims related to a specific hazard and the presence of urban settlements in the area covered by the eruption has been shown. However, pyroclastic falls are also extremely dangerous under certain conditions. These conclusions are based on archaeological and volcanological studies carried out on the victims of the well-known AD 79 eruption of Vesuvius that destroyed and buried the Roman city of Pompeii. The stratigraphic level in the pyroclastic deposit and the location of all the casualties found are described and discussed. The total number of victims recovered during the archaeological excavations amounts to 1150. Of these, 1044 well recognisable bodies plus an additional group of 100 individuals were identified based on the analysis of several groups of scattered bones. Of the former, 394 were found in the lower pumice lapilli fall deposit and 650 in the upper stratified ash and pumice lapilli pyroclastic density currents (PDCs) deposits. In addition, a tentative evaluation suggests that 464 corpses may still be buried in the unexcavated part of the city. According to the reconstruction presented in this paper, during the first phase of the eruption (August 24, AD 79) a huge quantity of pumice lapilli fell on Pompeii burying the city under 3 m of pyroclastic material. During
this eruptive phase, most of the inhabitants managed to leave the city. However, 38% of the known victims were killed during this phase mainly as a consequence of roofs and walls collapsing under the increasing weight of the pumice lapilli deposit. During the second phase of the eruption (August 25, AD 79) 49% of the total victims were on the roadways and 51% inside buildings. All of these inhabitants, regardless of their location, were killed by the unanticipated PDCs overrunning the city. New data concerning the stratigraphic level of the victims in the pyroclastic
succession allow us to discriminate between the sequential events responsible for their deaths. In fact, casts of some
recently excavated corpses lay well above the lower PDCs deposit, testifying that some of the inhabitants survived the
first pyroclastic current. Finally, during the PDCs phase the victims died quite rapidly by ash asphyxiation. From the attitude of some casts, it seems that some people survived the initial impact of the second pyroclastic current and tried to support head and bust during the progressive aggradation of the deposit at the base of the current.

A new archaeological site of Roman Age has been recently found engulfed in the products of Vesuvius activity at Somma Vesuviana, on the northern flank of the Somma–Vesuvius, 5 km from the vent. A 9 m deep, 30 by 35 m trench has revealed a
monumental edifice tentatively attributed to the Emperor Augustus. Different than Pompeii and Herculaneum sites which were completely buried in the catastrophic eruption of 79 AD, this huge roman villa survived the effects of the 79 AD plinian eruption as suggested by stratigraphic and geochronologic data. It was later completely engulfed in the products of numerous explosive volcanic eruptions ranging from 472 AD to 1631 AD, which were separated by reworked material and paleosols. The exposed burial sequence is comprised of seven stratigraphic units. Four units are composed exclusively of pyroclastic products each emplaced during a unique explosive event. Two units are composed of volcaniclastic material (stream flow and lahars) emplaced during quiescent periods of the volcano. Finally, one unit is composed of both pyroclastic and volcaniclastic deposits. One of the more relevant volcanological results of this study is the detailed reconstruction of the destructive events that buried the Emperor Augustus' villa. Stratigraphic evidence shows the absence of any deposit associated with the 79 AD eruption at this site and that the building was extensively damaged
(sacked) before it was engulfed by the products of subsequent volcanic eruptions and lahars. The products of the 472 AD eruption lie directly on the roman structures. They consist of scoria fall layers intercalated with massive and stratified pyroclastic density current deposits that caused limited damage to the structure. The impact on the building of penecontemporaneous lahars was more important; these caused the collapse of some structures. The remaining part of the building was subsequently entombed by the products of explosive eruptions (e.g. 512/536 eruption, 1631 eruption) and mass flows.

A new archaeological excavation on the northern slope
of Vesuvius has provided invaluable information on the eruptive
activity and post-eruptive resedimentation events between the late
Roman Empire and 1631. A huge Roman villa, thought to belong to the Emperor Augustus, survived the effects of the 79 A.D. Plinian eruption, but was mainly engulfed in volcaniclastic materials eroded and redeposited immediately after a subsequent eruption or during repose periods. Primary pyroclastic deposits of the 472 A. D. eruption are only few centimeters thick but are overlain by reworked volcaniclastic deposits up to 5 m thick. The resedimented volcaniclastic succession shows distinct sedimentary facies that are interpreted as debris flow deposits, hyperconcentrated flow deposits, and channel-fill deposits. This paper has determined that the aggradation above the roman level is about 9 m in 1,200 years, leading an impressive average rate of 0.75 cm/year.

Dirigente Settore Difesa del Suolo: Giulivo I.
Responsabile del Progetto CARG per la Regione Campania: Monti L.
Aree emerse
Isola di Procida
Coordinatore scientifico: D'Argenio B.
Redazione scientifica: Putignano M.L.
Direttore del rilevamento: Morra V.
Rilevatori: Perrotta A., Scarpati C.
Analisi petrochimiche: Fedele L.
Analisi geocronologiche 40Ar/39Ar: Calvert A.T., Insinga D., Lepore S.
Isola di Vivara
Coordinatore scientifico e Direttore del rilevamento: Sbrana A.
Rilevatori: Marianelli P., Sbrana A.
Aree marine
Coordinatori scientifici: D'Argenio B., Marsella E.
Redazione scientifica: Putignano M.L.
Isola di Procida
Direttori del rilevamento aree marine costiere (da 0 m a -30 m): Orrù P., Putignano M.L.
aree marine (oltre i -30 m): Aiello G.
Rilevatori subacquei aree marine (da 0 m a -30 m): Orrù P., Putignano M.L., Sgrosso A., Vecchio E.,
Rilevatori aree marine (oltre i -30 m): Aiello G., Budillon F., Conforti A.
Responsabile della sicurezza delle attività subacquee: Morgera V.
Acquisizione ed elaborazione dati area marina
geofisica: Aiello G., De Lauro M., Di Martino G., D'Isanto C., Giordano F., Innangi S., Passaro S., Ruggieri S., Sacchi M., Scotto di Vettimo P., Tonielli R
stratigrafia: Aiello G.
micropaleontologia: Ferraro L.
analisi granulometriche: Capodanno M., Molisso F.
Commissione di coordinamento CARG dei fogli geologici alla scala 1:10000:
per la Regione Campania: D'Elia G., Monti L., Putignano M.L.
per il Servizio Geologico d'Italia - ISPRA: D'Angelo S., Di Stefano R., Lettieri M.T., Papasodaro F.
Responsabili per l'informatizzazione: Luperini W., Pelosi N., Terlizzi F.
ENTI FINANZIATORI DEL PROGETTO:
aree emese: Regione Campania e Servizio Geologico D'Italia (ISPRA)
aree marine: Regione Campania e Autorità di Bacino Nord Occidentale della Campania

Note Illustrative
A cura di:
aree emerse: Fedele L., Morra V., Perrotta A., Scarpati C. (Isola di Procida)
Sbrana A (Isola di Vivara)
aree marine costiere da 0 a -30 m: Putignano M.L., Orrù P.E., Schiattarella M. (Isola di Procida)
Putignano M.L. (Isola di Vivara)
aree amrine oltre i -30 m: Aiello G., Budillon F., Conforti A., D'Argenio B.
Con i contributi di:
aree emerse: Calcaterra D. (geologia applicata Isola di Procida)
per le aree marine costiere (da 0 a -30 m): Sgrosso A., Vecchio E. (stratigrafia e biocenosi Isola di Procida)

The excavations that have been carried out for over two centuries in the Pompeii area have removed much of the
volcanic ash that had buried it following the Vesuvian eruption of 79 AD. Within the scope of this project it has been possible to reconstruct the pyroclastic sequence that emerged discordantly on the terraced buildings that follow the western slope of the Pompeii area. Wall bricks are embedded in the volcanic deposits and testify to the impact of the eruption on the Pompeian houses.

L’éruption du Vésuve de 79 apr. J.-C., dont on se souvient
comme d’un événement catastrophique, a en réalité donné
une seconde vie à Pompéi. La première s’est terminée par une
destruction partielle suivie d’un ensevelissement total sous
une couche d’environ 6 m de lapilli de pierres ponces et de
cendres ; puis Pompéi est reparue au bout d’environ mille sept
cents longues années.