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Assessing the history, dynamics and magnitude of pre-historic explosive volcanic eruptions relies heavily on the completeness of the stratigraphic records, the spatial distribution, and the sedimentological features of the pyroclastic deposits. Near-vent volcanic successions provide fundamental but often patchy information, both in terms of record completeness (e.g., scarce accessibility to the older deposits) and of the spatial variability of the sedimentological features. Hence, medial to distal sections increasingly represent essential integrative records.Campi Flegrei (CF) is among the most productive volcanoes of the Mediterranean area, with a volcanic history comprised of well-known caldera-forming eruptions (e.g., Campanian Ignimbrite, CI, ~40 ka; Neapolitan Yellow Tuff, NYT, ~14 ka). Furthermore, recent studies correlated a well-known widespread distal ash layer, the so-called Y-3, with a poorly exposed proximal CF pyroclastic unit (Masseria del Monte Tuff, 29ka), allowing a re-assessment of the magnitude of this eruption, now recognized as a third large-magnitude (VEI 6) eruption at CF. The discovery of this large eruption reduces drastically the recurrence intervals of large-magnitude events at CF and has major implications for volcanic hazard assessment.While the most powerful Late Pleistocene (e.g., post-NYT and partially post-CI) eruptions at CF have been the subject of extensive investigations, less is known about its earliest activity. Motivated by this knowledge gap, we have reviewed the research on Middle-Late Pleistocene eruptions from the CF (~160-90 ka) in light of new compositional (EMPA + LA-ICP-MS), grain-size distribution (dry/wet sieving and laser) and morphoscopy (SEM) data of tephra layers from proximal and distal settings, including inland and offshore records. Our study provides a long-term overview and cornerstone that will help provide future eruptive scenarios, essential for the quantification of recurrence times of explosive activity and in volcanic hazard assessment in the Neapolitan area. This overview sets the basis for modelling dispersion as well as eruptive dynamics parameters of pre-CI large-magnitude eruptions, needed to better understand the behavior of the CF caldera with a long-term perspective.

Stratigraphy and architecture of the fault bounding the sedimentary basins developed along the Eastern Tyrrhenian margin provide information on the kinematic of faults transversal to the Apennine chain. To understand how changes in geodynamic processes control the structural evolution of transverse faults in the thrust belt-backarc hinge zone, we performed the interpretation of a 2D strictly spaced seismic data set, tied to stratigraphic data of exploration wells and onshore data constrains, and a 3D basin analysis.On the basis of geometry and age of the basin infill, we dated three events of fault activity and a complex kinematics of Pliocene-Quaternary transverse faults. The first tectonic phase produced the oldest normal faults developed along the Latium margin. These faults, active between 5.1 and 3.2 Ma (MPL2-MPL3 and MPL4 succession), bound sedimentary basins filled by a Transgressive/Regressive succession made up of sands, silts and clays. They gradually migrated from the NE- trending (transversal to the Apennine chain), Pliocene in age, toward the NW-trending (parallel to the Apennine chain) during the Lower Pleistocene (1.8 MA, MPL6 succession). The displacement along these normal faults was transferred, or relayed, from one to the next one along accommodation zones, corresponding to transfer faults. Accommodation zones along major bounding structures are sites of intra-basinal highs, characterized by thinner sedimentary covers. The transfer faults, orthogonal to the normal faults, offset the basin depocenters. Whereas a positive inversion structure located near a transfer fault deforms the central basin rift. During the Lower Pleistocene the transform faults are transversal to the Apennines chain. These latter developed from the Latium margin to the Campania Margin.The third phase of the development of the transverse faults corresponds to a second episode of rifting of the Eastern Tyrrhenian margin. This event is linked to the activity of NE-trending normal faults, during the Middle Pleistocene since the 0.7 Ma, producing half-grabens and a deepening of the basement in the northwestern part of the Campania Plain and in Naples Bay. The stratigraphic succession architecture records the tilting of the fault block. During the middle Pleistocene along the Campania margin the transverse faults were reactivated as normal faults.The great variability in the tectonic evolution of the Tyrrhenian margin has been interpreted as strictly related to the complex and rapid geodynamic evolution of the area during Pliocene-Quaternary times: Pliocene slab retreat of the Adria plate, followed by Pleistocene growth of a Subduction-Transform-Edge-Propagator (STEP) fault along the northern margin of the Ionian slab.

In areas characterized by geologic variability and high demographic pressure, seafloor sediment characteristics and the study of contaminants are important to reconstruct the origin and pathway of both contaminants and the sediments from source to sink.The area off-shore the alluvial Sarno plain (Naples Bay, Eastern Tyrrhenian Sea) is bounded by the Vesuvius volcano in the northern part and by the carbonates relief of the Sorrento Peninsula in the southern part, and it is affected by metals contamination due the outflow of industrial vast.A Geochemical and physical parameters of the sediments were analysed along a transect moving from the coast until the 100 m of water depth with the aim to explore how the onshore documented contamination affect the offshore counterpart. Surface sediment samples collected from the offshore Sarno plain, were analysed for grain size, nutrients (TOC, TN, TP) and heavy metals (Hg, Cd, As, Cr, Ni, Cu, Zn, and Pb) to evaluate the contamination status, and processed using multivariate statistical analysis. A sediment survey along the transect has been used to evaluate: 1) the relative influences of parent lithology and anthropogenic effects offshore the Sarno river; and 2) the extension of the influence of the river in the submarine area.Four clusters are identified through PCA analysis: 1) the first resulted associated to the presence of As and Fe, low TOC content and prevalence of sandy fraction reflecting a geogenic contribution from Vesuvius Plan; 2) the second mainly include Cr, Cu, Zn, Pb and partially Cd and Hg, high TOC content and finest granulometry, reflecting the influence of the Sarno River discharges in the marine area; 3) the third include a variability in the Mn, Fe and TOC content. This area might reflect the Sorrento-Peninsula influence; 4) the forth include samples of the distal area in which a low contamination rate is displayed and irregular Hg and Cd pattern are verified, probably due to diffuse contamination origin and other coupling factorsResults indicate that 1) the area offshore Vesuvius displays physical and geochemical association mainly related to the natural origin of volcanoclastic sediments; 2) in the central area, the association of contaminants suggests their anthropogenic origin from the Sarno Plain, whereas the distal area, characterized by low rate of contamination, are mainly influenced by sediment from Sorrento Peninsula. Finally based on the contaminant and nutrient distribution it is possible to individuate the distribution of terrigenous sediments and organic matter of the Sarno delta deposits. The results show that the river should account as one of the main contribution sources of anthropogenic contaminants. Some metals contamination anthropogenic in origin and TOC in general decreased gradually with distance from the coast and in particular is limited to the area of deposition of the river discharge.Individuation of several marine sector with different geochemical associations permitted the reconstruction of source to sink contaminants pathway on the continental shelf.

Southeast Naples Bay represents a wide continental shelf environment with terrestrial sediment supply mainly from the Sarno River. The Sarno river basin, including about 500 km2 of the alluvial plain, is located in Campania Region (SW Italy) between the volcanic complex of Somma-Vesuvio (on the NW), the Sarno Mts. (on the NE), the Lattari Mts. (on the S), the Tyrrhenian sea (on the W) and the Picentini Mts. (on the E). Currently, the Sarno river, partially used for irrigation, is affected by an extreme environmental pollution as a result of the outflow of industrial waste. Consequently, the area of the Naples Bay is influenced by sediment loads derived from the Sarno River (Albanese et al., 2013; De Pippo et al., 2006).Seventy-one samples collected by van Veen grab) along a transect (long about 9 km) perpendicular to the coast has been used to evaluate: 1) the relative influences of parent lithology and anthropogenic effects offshore the Sarno river in the Southeast part of Naples Bay; and 2) the extension of the influence of the river in the submarine area. Different environmental indicators were selected for the contamination assessment such as total nitrogen (TN) and phosphorus (TP), total organic carbon (TOC), grain size of particles, metals, priority polycyclic aromatic hydrocarbons (16 USEPA, PAHs), total petroleum hydrocarbon (TPHs), volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), pesticides (OCPs) and organotin compounds (OTs).Two different statistical techniques, Principal Component Analysis and factorial Analysis of Variance (ANOVA), allowed us to recognize areas with different pollution features. The results of this study compared to the published onshore data permitted us to evaluate natural versus anthropogenic sources and to delimit the influence area of the Sarno River supply into the Naples Bay.References:Albanese, S., Iavazzo, P., Adamo, P., Lima, A., De Vivo, B. (2013) Assessment of the environmental conditions of the Sarno River Basin (South Italy): a stream sediment approach. Environ. Geochem. Health 35, 283–297. De Pippo, T., Donadio, C., Guida, M., & Petrosino, C. (2006) The case of Sarno river (Southern Italy). Effects of geomorphology on the environmental impacts. Environmental Science and Pollution Research, 13(3), 184–191.

This study reports and compares the application and usefulness of the Environmental Function Analysis to discover the potential for conservation of two very different coastal areas located along the Campania Region (Southern Italy). The first EFA site is located in the Volturno River Coastal Zone (southern Tyrrhenian sea) while the second EFA study site is located at the western end of the Sorrento Peninsula in the Bay of Naples. Results demonstrated that EFA permits to effectively synthetize the information on coastal system functioning and on their potential for conservation or development.

The Gulf of Naples located in a high anthropized coastal area is subjected to an infrastructural intervention for the installation of a submarine power pipeline. In order to evaluate the distribution of contaminants in the seafloor sediments, a preliminary study has been conducted in the area using multivariate techniques. The statistic approach was performed to gain insights on the occurrence of organic and inorganic contaminants within the area, aiming to identify the relevant hot spots. Three geographical sub-areas influenced by different contaminant association were recognized: Torre Annunziata (TA), Capri (CA), and middle offshore (MO). TA and CA resulted marked by a severe contamination pattern due to anthropogenic pressures. In addition, the influence of the depositional basin in governing the contamination trend has been pointed out. The supervised technique PLS_DA resulted to be a powerful tool in addressing the complexity of the huge dataset acquired during the marine survey, highlighting the main trends in the variability of quality indicators, orienting thus the deeper investigations during follow-up monitoring activities.

The correlation between onshore and offshore of the volcanic features in a complex volcanic field area is a difficult task, however, it is a fundamental step in order to better understand the geological evolution of such a complex area and for an assessment of geologic hazards. Ischia is a well exposed and densely populated volcanic field located in the Campania volcanic province of Italy. In order to improve our understanding of the recent volcanic history of Ischia Island, high-resolution seismic reflection profiles were used to identify volcanic and sedimentary features in the northern offshore. The volcano stratigraphy interpretation permitted us to recognize seismic units with a reflection-free/chaotic facies. These latter units have been associated with volcanic deposits and correlated to the main volcanic units outcropping on the northern coast of Ischia Island. They are limited in extent and interlayered with eight seismic units with continuous reflectors corresponding to clastic sedimentary units that were deposited during inter-eruptive phases. The main result of this work is the documentation of volcanic activity during the Holocene in the area offshore between Castello d'Ischia, Ischia Porto (mainly effusive products) and Punta della Scrofa (mainly shallow lava domes and dykes). The key volcanic units were mapped and 3D geological models were reconstructed. The reconstruction of the stratigraphic framework offshore a volcanic coast provides a pathway to the investigation of the stratigraphic relationships between inter-eruptive sedimentary deposits and volcanic units, and permits the assessment of a wide and continuous chronostratigraphic framework in a complex area. Furthermore, the onshore-offshore correlation of the main Holocene volcanic units allows us to better estimate their areal distribution, a critical factor in the hazard evaluation of a coastal volcanic area. The application of seismic volcano stratigraphy illustrates the remarkable possibilities that the study of submarine volcanic fields offers.

The main goal of this study is to investigate the anthropic influence on benthic habitats in the Punta Campanella Marine Protected Area (MPA). This area is located at the western end of the Sorrento Peninsula in the Bay of Naples, southern Italy. It is a rocky coast consisting of vertical or near vertical limestone cliffs of structural control, with marine areas characterized by suboutcropping rocky substrate. Seabed sediments are mainly coarse and biogenic in origin with skeletal grains and coralligenous bioconstructions occurring widely [1].The Punta Campanella seabed habitats have been characterized and mapped on the base of geophysical and sedimentological data together with results from benthic communities. In addition, several environmental components both marine and terrestrial have been analysed in order to evaluate the anthropic influence on the recognized benthic habitats. Such environmental components include foraminiferal assemblages, water column features and inorganic pollutants (heavy metals) as well as terrestrial biota, fresh water supply and quality, land use and natural hazard.First results indicate 1) anomalous values of specific heavy metals (Ni, Hg) in the marine sediments, 2) the presence of benthic foraminiferal assemblages distinctive of human-impacted environmental conditions, and 3) the occurrence of morphological deformities affecting some foraminiferal species. At present, as next step of this study, we are applying a methodology based on the Environmental Functional Analysis (EFA) in order to combine and analyse terrestrial and marine environmental components together with territorial data and selected socio-economic components of the coastal zone (i.e. human pressure, land use, etc.) [2]. This method was originally developed by Cendrero and Fischer (1997) [3] and successively employed as management tool and monitoring technique for coastal areas [4] and terrestrial protected areas [5]. Such a holistic-based approach can be used to evaluate the anthropic disturbance in the Punta Campanella MPA and to compare the potential for conservation and the potential for use of the study area.References[1] D'Argenio B., Violante C., Sacchi M., Budillon F., Pappone G., Casciello E., Cesarano M., 2004: Capri, Bocca Piccola and Punta Campanella (southern Italy), marine and onland geology compared. In: G. Pasquarè and C. Venturini (Eds), Mapping Geology in Italy, APAT, Roma, 35-42.[2] Hopkins, T.S., Bailly, D., Støttrup, J.G., 2011. A Systems Approach Framework for Coastal Zones. Ecol. Soc. 16(4), 25.[3] Cendrero A., Fischer D.W., 1997: A procedure for assessing the environmental quality of coastal areas for planning and management. Journal of Coastal Research 13(3), 732-744.[4] Giordano L., Ferraro L., 2020. Conservation or development? An environmental function analysis assessment of the Volturno River coastal zone (central Tyrrhenian Sea - Italy). Journal of Coastal Conservation, 24(6), 5-12.[5] Calado H., Bragagnolo C., Silva S., Vergílio M., 2016: Adapting environmental function analysis for management of protected areas in small islands e case of Pico Island (the Azores). Journal of Environmental Management 171, 231-242.

Most of the research works that aim at explaining the relationships between tectonic and volcanism focused a single volcano or eruption. Conversely, this study investigated offshore and onshore areas of the Campania margin in terms of stratigraphy, tectonics, and volcanism at a regional scale. We documented and reconstructed the three-dimensional geometry of several buried volcanoes and volcaniclastic deposits and recognized a complex Late Quaternary tectonic evolution of the region. These results suggest a strict genetic link between rifting and volcanic activity in terms of space-time evolution and because high volumes of magma rose to the surface through regional faults.

Most of the research works that aim at explaining the relationships between tectonic and volcanism focused a single volcano or eruption. Conversely, this study investigated offshore and onshore areas of the Campania margin in terms of stratigraphy, tectonics, and volcanism at a regional scale. We documented and reconstructed the three-dimensional geometry of several buried volcanoes and volcaniclastic deposits and recognized a complex Late Quaternary tectonic evolution of the region. These results suggest a strict genetic link between rifting and volcanic activity in terms of space-time evolution and because high volumes of magma rose to the surface through regional faults.

The Sarno River Basin (South-west Italy) is one of the most polluted river basins in Europe due to widespread industrialization and intensive agriculture. From the geological point of view, it lies between the Somma-Vesuvius volcanic complex and the limestone formations of the Campania-Apennine Chain. The goal of this work has been to establish the influence of the Sarno river on the present sedimentation in the Naples bay continental shelf by evaluating organic matter contribution and pollution. Sediments samples were collected, by van Veen grab, in 71 stations located offshore the Sarno river between Vesuvian and Sorrento Peninsula coasts. The characteristics of the surface sediments were analysed to highlight spatial trends in the (i) granulometry (grain-size); (ii) total nitrogen, organic carbon and total phosphorus; (iii) metal content (Hg, Cd, Pb, As, Cr, Cu, Ni, Zn, Fe and Mn). The sediment distribution suggested that sediments from the Sarno River prevailed in the central part of the bay between the sand grained deposits from Vesuvius and coarser grained sediments from Sorrento Peninsula. The Sarno River deposition is characterized by silt/clays rich in organic elements with a high water content. A comparison with a previous study carried out onshore in the Sarno river basin has allowed to interpret the elevated Pb, Zn, Cd, and Hg concentrations most likely related to geological and anthropogenic sources, to underlying volcanic rocks, and contamination from fossil fuel combustion associated with nearby urban centres. In particular, as verified onshore, Ni and Cr contamination is most likely originating from anthropogenic sources as the Solofra tannery industry; the results suggest as these metals have been dispersed offshore. All these elements permit to identify the distribution of the present Sarno prodelta and to identify the influence of the onshore anthropogenic pollution in the adjacent submarine area. First results from this study highlight the influence of the Sarno prodelta in Naples Bay and represent the first step in the characterization of a marine area strongly influenced by a very high populated and touristic coast. Therefore, the study represents a data base for the offshore environmental impact evaluation.

A multidisciplinary study, based on integration of eco-biostratigraphy and tephrostratigraphy, was applied to the sedimentary record of core CET2, recovered in a bathyal area of the Eastern Tyrrhenian Sea, along the Campania Continental Margin. An event stratigraphy of the Late Pleistocene–Holocene succession was obtained, also through the integration of the results coming from the study of the nearby CET1 core. A very detailed integrated stratigraphic framework was reconstructed for the last 40-ka time span, basing on the planktonic foraminifera eco-biozones and correlations of tephra layers. In the time interval older than 40 ka, the relationship between climatic events and tephra layers were highlighted. Some reworked intervals were identified at different stratigraphic levels; the thickest among these was identified just below the Campanian Ignimbrite tephra and interpreted as a debris flow. This deposit is here considered as the stratigraphic signature of the volcano-tectonic event of the Campanian Ignimbrite eruption. Other mass-transport deposits were identified below tephra layers related to very energetic eruptions, thus suggesting a possible link between the huge volcanic explosive eruptions of the Campania Volcanic Zone, coeval fault activity and the occurrence of mass-transport events in the study area.

The paper by De Natale et al. (2016, https://doi.org/10.1002/2015GC006183) reported new stratigraphic and geochronological data for a borehole located at Campi Flegrei volcanic area. The authors failed to mention several significant articles on the geological evolution of the region and proposed an interpretation of their data according to the caldera model. Herein, we provide tectonic and stratigraphic data to support a fault model of ignimbrite emission. This comment will also show the inconsistency of the proposed Campi Flegrei caldera.

In the Central Mediterranean the Africa-Eurasia convergence led to the development of complex orogenic systems and backarc basins. Throughout Pliocene-Quaternary times the Southern Apennines accretionary prism migrated towards the Apulia foreland and, contemporaneously, the Tyrrhenian Sea backarc basin opened. In this study, we investigated the offshore of the southern Apulia foreland and the Southern Apennines. Using seismic reflection profiles and well data in a dedicated GIS software, we made a detailed stratigraphic analysis, reconstructed the structural pattern and built 2D geological models of the main geological surfaces. The structure of the Apulia region formed during two main tectonic stages: lower Pleistocene complex extensional faulting developed in a transtensional regime and middle-upper Pleistocene transpression/shortening. The Southern Apennines accretionary prism developed through the Pliocene-early lower Pleistocene and was overprinted by late lower Pleistocene-middle Pleistocene NW-SE sinistral faults. Through linking new data from the accretionary prism and the foreland with previous information from the Tyrrhenian Sea back-arc, we provide an original interpretation for the relationships between the various provinces that make the Central Mediterranean crustal puzzle and reconstruct the main phases of the evolution of its Pliocene-Quaternary orogenic cycle. We recognized collisional stages of uncoupled plates, followed by late lower-middle Pleistocene post-collisional stages of coupled continental plates. This Pleistocene plates re-organization of Central Mediterranean was probably due to the rupture of the Apulia/Ionian slab or to NNW intraplate shortening transmitted from Africa.

Miocene extensional sedimentary basins are being increasingly recognized in Central Mediterranean. However the paleogeographic reconstruction of the Paleo-Tyrrhenian during this time span results a difficult task because the subsequent Pliocene-Quaternary backarc opening moved away these older sedimentary basins. Our study outlines principal deformation events recorded by sediments that were deposited within minor basins of the Tyrrhenian Sea region and provides constraints on the duration of these events. The interpretation of seismic profiles, wells, and outcrops data together with a review of the middle-upper Miocene successions permitted us to recognize Miocene third order depositional sequences, reconstruct the fault pattern, and furnish a detailed evolution of the sedimentary basins that preceded the Pliocene-Quaternary Tyrrhenian high stretching. Based on the stratigraphic and tectonic constraints together with the age migration of the depocenters, we reconstructed a detailed paleogeographic evolution of central Mediterranean. Sedimentary basins architecture and fault pattern indicate a system of approximately N-S oriented normal faults and approximately E-W transform faults that were active since the Late Oligocene. Two period of extensional/transtensional tectonics (late Oligocene-Lower Burdigalian and Upper Langhian-Tortonian) were interrupted by a compressional event (late Burdigalian-Lower Langhian). Tacking in account the position of the Miocene volcanic arc (Sardinia), we propose that the coeval sedimentary basins developed in the central Mediterranean as forearc extensional/transtensional basins during the progressive collision with the African plate and before the Tyrrhenian backarc opening. Unlike published late Oligocene-Tortonian reconstructions of the western-central Mediterranean realm that report a linear migration of backarc extension, our results support a geodynamic model characterized by a progressive deformation of the forearc extension in the overriding plate.

Central-southern Italy is one of the most suitable areas in the world for tephrostratigraphic studies, owing to the numerous volcanic sources with explosive activity during the Pleistocene. This work presents a systematic investigation of the chemical (trace elements) and isotopic (Sr and Nd) compositions of the main tephra markers within lacustrine sediments of the San Gregorio Magno Basin (Campania, southern Italy). This study: (i) provides full geochemical (trace elements and isotopes) characterization of eight significant Upper Pleistocene marker layers (X-6, X-5, C-22, MEGT/Y-7, CI/Y-5, C-10, Y-3, NYT/C2) widely dispersed over the Mediterranean area; (ii) proposes a new tephra marker for Marine Isotope Stage 7, dated to 240 ka; and (iii) refines the correlations of tephra levels belonging to the investigated sequence. This study highlights that in most cases the Nd isotope composition of the glass and Sr isotope composition of the coexisting minerals are more reliable than Sr-87/Sr-86 of the glass, and hence is more helpful as a further tool for tephrostratigraphic correlations, as recently proposed in the literature. Moreover, this study is a first step towards the construction of a complete geochemical database for future tephra investigations in the Mediterranean area.

The Tyrrhenian Sea (Central Mediterranean) is an extensional area that formed during the collision between Africa and Eurasia. Through the analysis of well logs and seismic profiles we reconstructed the stratigraphic successions and the structural style of the Tyrrhenian sedimentary basins. The sequence stratigraphy interpretation of well logs permitted us to recognize third and fourth order depositional sequences and the stratigraphic signatures of the rift stages. The study area features several sediment overfilled/balanced infill basins that resulted from the superposition of several rifting events characterized by high rates of basin subsidence. These outcomes led us to propose five rifting episodes occurred from Miocene to Quaternary affecting the upper plate. The suggested geodynamic scenario takes into account a progressive rupture of the slab and formation of sedimentary basins in the upper plate.

Coeval rifting processes affecting both backarc, thrust belt and foreland occurred in offshore western Sicily (Central Mediterranean) as indicated by the analysis of a large seismic data set calibrated with well data, onshore data and dredges in a dedicated GIS software environment. Structural pattern of the investigated area, 3-D geological models and a Pliocene-Lower Pleistocene evolution of extensional sedimentary basins have been reconstructed. In detail, two zones characterized by basins with different directions of extension have been recognized: one trending NE-SW, located south of the Egadi Islands; another trending E-W, positioned north of the Egadi Islands. The first group of basins represents the continuation of those of the Africa foreland basin (Pelagian Block), as the second one characterizes the opening of the backarc (southern Tyrrhenian margin). Both basins affect the collisional chain (Maghrebian thrust belt). An eastward progression of extension, from lower Pliocene to lower Pleistocene, based on different onset of the basin fill, has been documented in the Southern Tyrrhenian margin. The study area represents the meeting place of backarc and foreland rifting that affected the late Miocene thrust belt. The recognized pattern of extensional deformation of the upper plate adds some constraint on the geodynamic evolution of the African and Eurasia plates and supports a model of westward dipping slab in the Central Mediterranean. It is hypothesized that the along-trench variation of the nature of the plates, due to paleo-margin configuration, has a profound impact on the upper crustal deformation during the convergence and thus the meeting place of backarc and foreland rifting could represent the surficial signature of the slab detachment since Pliocene times.

The direction of extension and the architecture of the Messinian basins of the Central Mediterranean region is a controversial issue. By combining original stratigraphic analysis of wells and seismic profiles collected offshore and onshore Calabria, we reassess the tectonic evolution that controlled the sedimentation and basement deformation during Messinian times. Three main deep sedimentary basins in the Calabria area record a Messinian succession formed by two clays/shales-dominated subunits subdivided by a halite-dominated subunit. The correlation with the worldwide recognized stratigraphic features permit to define the chronology of the stratigraphic and tectonic events. Three main rift basins that opened in a N-S direction have been recognized. On the contrary a fourth supradetachment basin opened toward the East. We found that the basin subsidence was controlled by two stages of activity of normal faults and that Messinian rift basins evolve in a deep-water environment. The overall pattern of extensional faults of the Central Mediterranean corresponds to normal faults striking parallel to the trench and normal faults striking at an oblique angle to the trench (Fig. 14). In particular in Campania and Calabria regions are present two rifts parallel to trench and an intervening rift orthogonal to the trench. We maintain that the recognized Messinian rift basins can be interpreted according to the “Double-door saloon tectonics”.

The southern Apulia foreland recorded a strong (Imax=X MCS) earthquake in 1743 and a concomitant tsunami, which struck the southeastern Salento coast. The seismo-genetic fault and the triggering factors of the tsunami are unknown. Three-dimensional interpretation of multichannel seismic profiles calibrated by wells using a GIS software enabled the recognition of the stratigraphic succession, structural framework, and submarine landslides offshore Salento. A thin Pliocene unit overlying the Mesozoic-Cenozoic substrate is covered by a Pleistocene succession separated by a Middle Pleistocene unconformity that formed during the regional uplift of Salento. The latter gave rise to the morphologic conditions for the deposition of a prograding wedge off the Salento coast, with a shelf break located at 150 m depth. Normal faults, mainly oriented NW-SE, displaced the early Lower Pleistocene succession and are buried by younger deposits. Since the Middle Pleistocene, a compressional event gave rise to the Apulia uplift and large folds and basement-involved reverse faults that are active in the eastern part of Apulia. A huge (58 km(3)) slump affecting the Middle Pleistocene prograding wedge has been documented offshore the southeast coast of Salento. The proposed geological scenario of the 1743 earthquake and subsequent tsunami is (1) an initial strong earthquake (Imax=X MCS) associated with a thrust fault located in the eastern sector of the Apulia offshore, (2) a shacking-induced large-volume slump offshore Otranto, and (3) landslide-triggered tsunamis that struck the Salento coast.

The Southern Tyrrhenian Sea is an extensional basins linked to the Neogene evolution of the Calabria subduction zone located in the western Mediterranean realm where controversial kinematic and geodynamical models have been proposed. Our study provides a key to unravel timing and mode of extension of the upper plate and the breakup of Calabria from Sardinia. By combining original stratigraphic analysis of wells and seismic profiles off Calabria with a stratigraphic correlation to onshore outcrops, we re-assess the tectonic evolution that controlled the sedimentation and basement deformation of the Southern Tyrrhenian basin during Serravallian–Tortonian times. We document the tectono-stratigraphic evolution of adjacent extensional basins characterized by 3rd order depositional sequences (Ser1, Tor1 and Tor2) and different modes of extension, subsidence and opposite dipping faults. Episodic basin development is recorded by a coarsening-up and fining-up trend of the sedimentary succession and by tectonically enhanced unconformities that reflect three episodes of fault activity. We reconstruct Serravallian–Tortonian paleogeographic maps and propose a block faulting model for the evolution of the Sardinia–Calabria area. Sardinia was disconnected from Calabria through N–S normal faults forming Tyrrhenian extensional basins that formed contemporaneously to the E–W opening of the Algerian basin. Unlike published Serravallian–Tortonian reconstructions of the western Mediterranean realm, our results support a geodynamic model characterized by rapid trench retreat, trench-normal extension in the entire overriding plate and very weak coupling between plates.

Current models for the opening of the Tyrrhenian Sea invoke a unique extension vector throughout the rift to drift process, accommodated by margin parallel faults, but the role of the Campania margin faults in the opening of the Tyrrhenian back-arc basin is still poorly constrained. Gaeta Bay, located on the Campania mar- gin, was investigated through the interpretation of seismic reflection and borehole data together with a strat- igraphic correlation of dated outcropping units. The interpretation of a seismic grid using seismic and sequence stratigraphy and structural geology approaches in a dedicated GIS environment led to the genera- tion of 2-D models of relevant geological surfaces, isochron maps, a 3-D digital model of the subsurface and to the reconstruction of the geological evolution of the margin with a resolution of 100 ka. Gaeta Bay is formed by three basins (northern, central and southern) and features a complex stratigraphic architecture: in the northern and central basins a syn-rift deposit (unit PP) is buried by the oldest aggradational deposit (unit A) that fills the accommodation space; a post 0.7 Ma succession (units B and C) filled the northern basin with a lateral aggradational geometry; a syn-tectonic wedge (unit B) was deposited in the central basin between 0.7 and 0.4 Ma; post 0.4 Ma thick deposits (unit C) are testimony to the collapse of the southern basin. A correlation between the geology of the bathyal basin and that of the Campania margin was established using a CROP seismic section that extended from the Vavilov basin to Gaeta Bay. Based on original and literature data we propose a kinematic evolution of the Tyrrhenian Sea upper plate over the last 10 Ma. This evolution consists of older extensional events (stages 1-2) off Sardinia and in the Vavilov basin (leaving the Campania margin unaffected). Younger events (stages 3-5) developed in the eastern (with a Pliocene-Quaternary change of the extension direction along the Campania Margin) and central Tyrrhenian region. This paper suggests that the Tyrrhenian Sea opening was a polyphase rifting with a migration of activity and a change of style over time (including a period of lithospheric detachment faulting). © 2013 Elsevier B.V. All rights reserved.

The basal portion (2.92–5.08 m from core top) of the CET1 core located in a bathyal area of the eastern Tyrrhenian Sea is the subject of a multidisciplinary investigation, encompassing tephrostratigraphy, quantitative analyses of planktonic foraminifera and calcareous nannofossil assemblages, and δ18O measurements, supported by a 40Ar/39Ar age determination. Calcareous nannofossil assemblages allowed the attribution of the analyzed sediments to the biozone MMN21a, and the succession spans from more than 48 to ca. 105 ka, although there are at least two stratigraphic gaps and minor resedimentation episodes. A paleoclimatic reconstruction obtained via δ18O and planktonic foraminifera data identifies several of the major climatic events that occurred in the investigated time span. A total of 13 visible tephra layers and cryptotephras are recognized and correlated with their volcanic sources (Campanian Volcanic Zone and Pantelleria volcano) and, when possible, with well-known and dated events or with widespread marker tephras. Using a combination of biostratigraphic, oxygen isotope, and tephrostratigraphic correlations, we develop a chronostratigraphy for the main climatic events and tephra layers in the core and pinpoint tephra markers for the climatic events comprised between GS 22 and GI 24 in the eastern Tyrrhenian Sea.

In the recent decades many studies have been carried out on rift formation, in order to understand causes and modes of whole lithospheric extension. Extensional basins have been studied and classified using 2D geological sections and thus also modelled prevalently in 2D. However, the complete process of continental break-up can be understood only through detailed 3D studies of rift evolution at varying stretching factors (Reston and Pe?rez-Gussinie?, 2007).The Tyrrhenian Sea, the youngest backarc basin of the Western Mediterranean (e.g., Dewey et al., 1989), is characterized by crustal thinning and opening of sedimentary basins (including the Vavilov basin). Within this geological framework, the Vavilov basin represents a perfectly preserved fossil triangular basin, where the extensional processes reached the mantle exhumation stage during the Pliocene (Mascle and Rehault, 1990; Milia et al., 2013) and moved eastwards in the Quaternary (Milia and Torrente, 2015; Milia et al, in press).In this study, we interpret seismic reflection profiles and wells data, in order to reconstruct the architecture and timing of rifting of the Vavilov basin. Our results show rift and supradetachment basins in the Vavilov rift zone and, for the first time, the kinematics of the entire triangular basin (from apex to distal zones). Furthermore, we compare the development of the Vavilov basin with two evolutionary models of triangular basins: a) the plate tectonic rift model, featuring a synchronous opening across the whole basin, from apex to the distal part around a rotation pole; b) the propagating rift model, characterized by an extension migration from the distal to the apex of the basin. On the base of this comparison and the crustal structure of the Vavilov basin (Tesauro et al. 2008), we propose a model of tectonic evolution of the study region. We observe that the apex basin corresponds to a sediment-balanced basin, with a sedimentary infill recording the episodes of basin evolution. In contrast, the distal basin corresponds to an underfilled basin, characterized by localized volcanic activity and a thin sedimentary succession that covers the exhumed mantle. We find that the rifting of the Vavilov triangular basin was synchronous from the apex to distal regions around a single Euler pole located in Latium. The kinematic evolution of the Vavilov basin occurred in two stages: initial pure shear mode produced high-angle normal faults and syn-sedimentary wedges, followed by simple shear mode that caused supradetachement. This interpretation implies also that the continental crust in the bathyal region has been locally thinned and extended more significantly than previously estimated. Based on constraints on the present-day crustal structure of the Vavilov basin, we obtain a stretching value (b =3.5) and extension rates (3 cm/yr) in the bathyal zone analogous to those reported for magma-poor rifted margins.

The style of extensional basins provides key insights into the magnitude of extension and their kinematic evolution. The newly documented Stilo rift (off Calabria, Italy) features a Serravallian–Tortonian rift basin bounded by a high-angle normal fault and a Messinian adjacent supradetachment basin bounded by a low-angle normal fault. We propose a kinematic model suggesting the abandonment of the high-angle normal fault and the beginning of low-angle normal fault activity, followed by a rapid increase in extension. The triggering mechanism of the low-angle normal faults can be attributed to rapid rollback of the subducting plate and/or to isostatic crustal uplift. Supplementary material: The seismic dataset and methods of interpretation are available at http://www.geolsoc.org.uk/SUP18794.

Three crustal geological sections of the Campanian Volcanic Zone (Italy) were reconstructed by integrating basin architecture and deep well stratigraphies. In addition, mapping of the fault system and of large-volume ignimbrites was carried out. A linked fault system has been identified, which was responsible for asymmetric subsidence contemporaneous with the eruption of ignimbrites. Late Quaternary extension is characterized by a WNW–ESE stretching axis, NNE–SSW normal faults and reactivation of inherited structures. Structural, stratigraphic and palaeogeographical analyses reveal evidence for up to 750 m of subsidence, which has occurred at a mean rate of up to 4.9 mm a −1 over the past 154 ka. These rates suggest that extensional tectonics was responsible for the regional subsidence. A 6 km deep seismic reflector was associated with a magmatic reservoir underlying Campi Flegrei. By matching the structural and stratigraphic architecture with published geophysical and geochemical data a crustal tectonomagmatic model was constructed that displays high-angle faults that root into a low-angle detachment, which in turn roots into a deep sill-like magma reservoir. This model suggests the possible role of extensional faults in localizing magmatic activity, as faults controlled magma rise from deep to shallow reservoirs and to the surface during ignimbrite eruptions. Supplementary material: Seismic reflection profiles and interpretations are available at http://www.geolsoc.org.uk/SUP18451.

The Southern Campania Margin (SCM) represents a key area of the Central Mediterranean because it records all the rifting stages of the Tyrrhenian Sea. The interpretation of a seismic dataset calibrated with deep wells and outcrops, using seismic stratigraphy and structural geology methods in a dedicated Geographic Information System (GIS) environment, the seismic depth conversion, the generation of 2-D and 3-D models led to the reconstruction of a polyphased tectono-stratigraphic evolution of the SCM. During the early stage of Tyrrhenian opening a terrigenous transtensional Basin (Langhian-Tortonian Cilento Basin) formed on the Liguride accretionary prism adjacent to the Calabria crystalline terrane. In the SCM the Liguride thrust sheets tectonically overly the Apennine Platform units and both these nappes have been dismembered by Quaternary faults. Three rifting stages, not homogeneously distributed, affected the region since the Lower Pleistocene. They are associated to the deposition of a thick Quaternary succession (A, B and C units). During these Pleistocene stages there was an abrupt change of the extension direction (from NE-SW to NW-SE) accompanying a change of the nappe transport direction of the Southern Apennines. The construction of balanced sections using dedicated software, permitted us to recognize the true geometry of the faults and compute the amount of Quaternary extension of the SCM that results comparable to those calculated for other sectors of the Tyrrhenian margin and further extensional regions worldwide.

Campi Flegrei (CF) is a large volcanic complex located west of the city of Naples, Italy. Repeated episodes of bradyseism (slow vertical ground movement) near the town of Pozzuoli have been documented since Roman times. Bradyseismic events are interpreted as the consequence of aqueous fluid exsolution during magma solidification on a slow timescale (10(3)-10(4) yr) superimposed upon a shorter (1-10 yr) timescale for the episodic expulsion of fluid from a deep (similar to 3-5 km) lithostatically-pressured low-permeability reservoir to an overlying hydrostatic reservoir. Cycles of inflation and deflation occur during short duration transient events when connectivity is established between deep and shallow hydrothermal reservoirs. The total seismic energy released (4 x 10(13) J) during the 1983-1984 bradyseismic crisis is consistent with the observed volume change (uplift) and consistent with the notion that seismic failure occurs in response to the shear stress release induced by volume change. Fluid transport and concomitant propagation of hydrofractures as fluid expands from lithostatic to hydrostatic pressure during decompression leads to ground surface displacement. Fluid decompression occurs along the fluid isenthalp (Joule-Thompson expansion) during transient periods of reservoir connectivity and leads to mineral precipitation. Each kilogram of fluid precipitates about 3 x 10(-3) kg of silica along a typical decompression path along the isenthalp. Mineral precipitation modifies the permeability and acts to reseal connection paths thereby isolating lithostatic and hydrostatic reservoirs ending one bradyseism phase and beginning another. Crystallization and exsolution of the magmatic fluid generates approximate to 7 x 10(15) J of mechanical (P Delta V) energy, and this is sufficient to accomplish the observed uplift at CF. Although magma emplacement is the ultimate origin of bradyseism, fresh recharge of magma is not a prerequisite. Instead, short to intermediate timescale phenomena associated with fluid decompression and expansion in the crust with large variations in permeability, including permeability anisotropy, are the key elements at CF.

We use seismic reflection profiles of diverse resolutions integrated with high resolution bathymetry and calibrated by deep wells, piston cores and field data to derive a structural and stratigraphic interpretation of the Southeastern peri-Tyrrhenian Basins. The study area is located in the Southeastern Tyrrhenian Sea offshore Calabria. We document a tectono-stratigraphic evolution of the sedimentary basins from the Serravallian to the Present. The basins formation started during the Serravallian and the area was successively affected by E–W normal faulting and approximately N–S transfer faults in the Messinian–Lower Pleistocene time range. During the Lower Pleistocene the tectonic depressions, completely filled with sediments, were affected by folding associated with transcurrent tectonics along a NW-trending left lateral fault. Finally, during the Middle Pleistocene, a change in the slip direction produced minor pull-apart basins that overprinted the folds. The basin analysis revealed the stratigraphic signature of the tectonic events and, the uplifting and subsiding areas and the direction from which sediments arrive into the tectonic depression. The four-dimensional geologic reconstruction of the Margin of Calabria furnished new constrains for the kinematic evolution of the Southeastern peri-Tyrrhenian Basins. We suggest that the superposition of different structural styles reflects a variation of the relative velocity between the Southern Apennine Arc and the Calabria Arc during the formation of the Apennine Thrust Belt.

The interpretation of high-resolution seismic profiles acquired close the eastern coast of the Bay of Naples offshore Somma-Vesuvius volcano, and calibrated by borehole data, allowed us to recognize a reflection-free seismic facies consisting of a volcaniclastic debris avalanche overlain by pyroclastic density current deposits. Both are associated with the 3.5 ka 'Avellino eruption' and are in turn overlain by a marine succession. The top of the volcaniclastic unit corresponds to a deep erosional surface covered by a coarse-grained bioclastic layer with rounded pumice. We argue that these features are related to a tsunami that was triggered by the sudden entrance into the sea of the gigantic (>1km3) volcaniclastic unit. The onshore-offshore correlation and mapping of this volcaniclastic unit have allowed us to evaluate its distribution west of Somma-Vesuvius. The pyroclastic density current deposits terminate seaward at 40 m water depth; at the same depth the debris avalanche is affected by a gravitational instability. Over the last 3.5 ka the slump has been in constant movement, as documented by the angular unconformities at the top of the chaotic seismic unit and within the overlying marine deposits. © The Geological Society of London 2009.

The interpretation of high-resolution seismic profiles and core data collected in the western Somma-Vesuvius volcano documents a stratigraphic unit consisting of a voluminous debris avalanche that was covered by pyroclastic gravity current deposits after entering the sea. Based on the stratigraphic position together with the ages of the dated Somma-Vesuvius Plinian eruptions, this unit was linked to the ∼3.5 ka-old Avellino Plinian eruption and correlated and mapped in offshore and onshore areas. The deposition of the thick Avellino unit had a strong impact on the physical environment of the volcano's western sector, producing hundreds of metres of prograding coastline and the formation of a morphological barrier in the alluvial plain. The striking erosional and depositional features that characterise the top of the Avellino unit along the coast suggest that the entrance of the debris avalanche into the sea triggered a tsunami that struck the Naples Bay coast. The hazardous geologic events include both the sea-facing flank failure of the volcano (producing the debris avalanche and tsunami) and the Avellino Plinian eruption (producing pumice fall and surge clouds) that profoundly affected several human settlements located within a 20 km radius of the volcano, causing the decline of the Bronze Age communities.

The ad 79 Plinian eruption of Vesuvius that buried Pompeii and Herculaneum began with pumice falls deposited towards the SE of the volcano followed by pyroclastic currents directed towards the SW. These currents reached Herculaneum and rapidly entered the sea, forming a fan. The interpretation of seismic reflection profiles and gravity cores collected off Herculaneum documents a submarine fan-shaped pyroclastic body at 10–140 m water depth that we interpret as the submarine counterpart of the onshore pyroclastic current deposits. This fan, c . 0.3 km 3 in volume, displays a chaotic seismic facies that changes seaward to parallel reflectors and then to wavy reflectors. Gravity cores reveal a succession consisting of centimetre-thick sand- or silt-sized ash couplets followed by a graded gravelly sand-sized bed up to 180 cm thick, containing shell fragments and beach-derived pebbles, overlain by centimetre-thick graded and laminated sandy ash layers. The depositional textures and sedimentary structures of the submarine pyroclastic fan have been interpreted as the product of the interactions between pyroclasts, water waves and tsunamis induced by the ad 79 pyroclastic density currents into the Bay of Naples.

The interpretation of high-resolution seismic profiles and core data collected in the western Somma-Vesuvius volcano documents a stratigraphic unit consisting of a voluminous debris avalanche that was covered by pyroclastic gravity current deposits after entering the sea. Based on the stratigraphic position together with the ages of the dated Somma-Vesuvius Plinian eruptions, this unit was linked to the similar to 3.5 ka-old Avellino Plinian eruption and correlated and mapped in offshore and onshore areas. The deposition of the thick Avellino unit had a strong impact on the physical environment of the volcano's western sector, producing hundreds of metres of prograding coastline and the formation of a morphological barrier in the alluvial plain. The striking erosional and depositional features that characterise the top of the Avellino unit along the coast suggest that the entrance of the debris avalanche into the sea triggered a tsunami that struck the Naples Bay coast. The hazardous geologic events include both the sea-facing flank failure of the volcano (producing the debris avalanche and tsunami) and the Avellino Plinian eruption (producing pumice fall and surge clouds) that profoundly affected several human settlements located within a 20 km radius of the volcano, causing the decline of the Bronze Age communities.

The Campania Plain is a rapidly subsiding Quaternary basin that formed on the eastern margin of the Tyrrhenian Sea in association with the younger phase of Tyrrhenian rifting. It is located in the hinge area between the Apennines fold-thrust belt and the Tyrrhenian extensional backarc basin. By combining original stratigraphic analyses of well logs and seismic profiles we built a basin subsidence curve, mapped the fault pattern of the Campania Plain and analyzed the impact of the block faulting on the sedimentology and stratigraphic architecture of the basin fill. Well data indicate that the Quaternary succession consists of offshore, shoreface and coal-bearing coastal plain deposits arranged to form thick aggradational and retrogradational units. The sequence stratigraphy interpretation of well logs permitted us to recognize thirteen depositional sequences and the stratigraphic signatures of the rift stages. The study area corresponds to a sediment overfilled/balanced infill basin type that resulted from superposition of several rifting events characterized by high rates of basin subsidence.Taking into account the geological data of the adjacent areas, we propose a Pliocene-Quaternary rifting evolution of the upper Tyrrhenian plate consisting of four episodes. Two peculiar features of the Tyrrhenian rifting are a skip of the extensional axial zone eastwards leaving the previous zone of high strain localization (Vavilov basin), followed by a dramatic change (90) of the direction of extension. Because these Tyrrhenian features cannot be accounted for by the current rifting models we hypothesized a link between the evolution of upper plate and subducting slab. The proposed geodynamic scenario is characterized by a progressive rupture of the subducting plate and formation of extensional basins in the upper plate. (C) 2015 Elsevier Ltd. All rights reserved.

Sedimentological and chemical analysis of gravity core samples, along with the interpretation of very high resolution, single channel seismic reflection profiles acquired off the Sarno prodelta system (southeastern Naples Bay), document the sedimentary facies and seismic stratigraphic signature of the tephra deposit erupted by Vesuvius during the plinian eruption of 79 AD. The 79 AD pyroclastic deposits sampled off the Sarno prodelta system revealed significantly different characters with respect to both the subaerial succession documented from the type sections of Pompeii, Herculaneum and Oplontis and the more distal pyroclastic fallout deposits that were recovered from the outer continental shelf off the northern Salerno Bay. This was likely to be expected as, in proximal subaqueous settings, both primary deposition and reworking of tephra are known to be influenced by the hydrodynamics of the water itself (induced by the pyroclastic currents entering the sea) as well as by the early instability of pyroclastic bedforms due to the exceptionally high sediment yield during volcanic eruption. According to the data illustrated and discussed in this study, we suggest that the 79 AD tephra deposit sampled off the Sarno prodelta is likely to be the result of a number of syn-eruptive genetically-related depositional and/or erosional mechanisms associated with (1) anomalous waves (tsunami) and currents generated by the entrance of pyroclastic flows and surges into the sea; (2) subaqueous density flows evolved from the impact of hot pyroclastic currents into the seawater; (3) failure of water-logged, cohesionless pumice deposits, due to instability of pyroclastic bedforms rapidly accumulating on the seafloor. Seismic interpretation revealed that the Upper Holocene sequence off the Sarno prodelta system is affected by extensive creep involving the whole post-79 AD succession. Deformation due to creep is documented by slumping of semi-consolidated strata over a basal surface represented by the lithologic discontinuity between the base of the 79 AD tephra deposits and the underlying hemipelagite. Seismic data also suggest that gravitational instability of this area has been induced, or enhanced, by significant volcanotectonic deformation and local uplift of the seafloor that ostensibly predated the eruptive event. The results of this research may be relevant to studies of other eruption events in close proximity to coastlines in terms of wave- and/or current-generated sedimentary features as a possible explanation of unusual subaqueous facies architecture.

¶The crustal structure of the Campania continental margin is synthesized from outcrop, seismic reflection and gravimetric data. Outcrop and subsurface geological data reveal the presence of NE–SW faults, E–W faults and NW–SE faults. An older extensional event occurred along NW–SE faults and was followed by the main extensional event linked to the activity of NE–SW normal faults. The latter were active between 700 and 400 ka producing half-grabens filled by more than 5 km of Quaternary deposits. The stratigraphic signature of these tectonic events corresponds to a Lower Pleistocene marine unconformity-bounded unit overlain by Middle Pleistocene rocks belonging to a transgressive-regressive cycle. A crustal section of the Campania margin displays an asymmetric linked fault system characterized by a 10–12 km-deep main detachment level, listric normal faults and rollover anticlines. Structural and stratigraphic data document that the inception of volcanic activity at Vesuvius occurred at 400 ka, just after the main extensional event, and the volcano is located at the margin of a rollover anticline.

¶The Campanian continental margin is characterised by asymmetric half grabens and large-volume volcanic deposits. Vesuvius and Campi Flegrei are active volcanoes located along the coast of Naples Bay along one of these half grabens. The interpretation of an extensive set of seismic reflection data allowed to reconstruct the stratigraphy and structural pattern in Naples Bay and their relationships with volcanism. The stratigraphic succession is characterised by a complex architecture due to the presence of 157 Ka old submarine and subaerial vents, pyroclastic flow units associated to the Campanian Ignimbrite and the Neapolitan Yellow Tuff, and numerous tuff cones younger than 12 Ka. These volcanic units occur within marine sediments deposited during the late Quaternary sea level oscillations. The structural pattern is characterised by late Quaternary NE- trending normal faults, NW-trending transtensional faults, E–W trending left-lateral faults and WNW-ESE directed folds. The overall fault kinematics and the evaluated very high displacement rates are consistent with an E-trending left-lateral transtensional shear zone located between 41° and 40° N latitude. The relationship between volcanism and tectonics in the Bay of Naples is explained with block rotation associated with this shear zone. Finally, tectonic and stratigraphic data argue against the occurrence of a caldera in the Bay of Naples.

Somma–Vesuvius is an active volcano with a breached crater close to the continental shelf of Naples Bay, Italy. The interpretation of high-resolution seismic profiles offshore of Somma–Vesuvius shows interlayered volcanic and marine units in the Late Quaternary succession. In particular, the detailed seismo-stratigraphic analysis permitted, for the first time, the identification and mapping of two thick debris avalanche deposits located on the continental shelf. With a volume of 2.9 km 3 , the older debris avalanche, linked to the 18 ka Pomici di Base plinian eruption, was emplaced in a subaerial environment and then overlain by the sedimentary deposits of the lowstand prograding wedge. The younger debris avalanche, linked to the 3.4 ka Avellino plinian eruption, has a volume of c . 1 km 3 and is interlayered within the marine sediments deposited during the sea-level highstand. The identification of two debris avalanches originating from Somma–Vesuvius has two important implications: (1) the occurrence of two sector collapses in the history of Somma–Vesuvius volcano; (2) a potential volcano slope failure and consequent tsunamis produced by the entry of a debris avalanche into Naples Bay should be considered in the volcanic hazard evaluation of this densely populated area.

Pozzuoli Bay is located in the eastern Tyrrhenian Sea and is an area characterized by active tectonics and volcanism. On the basis of high-resolution seismic reflection profiles, it was possible to reconstruct the stratigraphy and three-dimensional stratal architecture of the Holocene succession. Two volcanic units and three sedimentary ones were recognized. The basal unit NC consists of volcanic deposits and dates at 10.0–8.0 ka B.P. It is followed by unit D, deposited between 8.0 and 5.5 ka B.P., which displays a backstepping configuration in the central area and a forestepping configuration in the northern area. Unit D is covered by the progradational unit B which is elongated in a SE-NW direction. Unit C is interbedded between unit B and is interpreted as the volcanic products of the Agnano-Monte Spina eruption which occurred 4.4 B.P. Unit A, the youngest unit, shows a progradational configuration and is elongated in a E-W direction. The sedimentary units record the transgressive and highstand of the eustatic sea level. They show vertical and lateral variations in the depositional architecture. Changes in the stacking pattern record variations in tectonic subsidence and hydrodynamic regimes.

The Campania Volcanic Zone, located on the eastern margin of the Tyrrhenian Sea, is a region characterized by active volcanoes and ignimbrite deposits. Well-known active volcanoes include Campi Flegrei, Vesuvius, and Ischia. Over the last 15 years, numerous volcanoes, domes, pyroclastic units, and debris avalanche deposits have been discovered offshore of Campania, which has allowed new volcanic fields to be identified and the volumes of ignimbrite deposits to be quantified. Sequence stratigraphy is focused on analysing changes in the facies and geometric character of strata and on identifying key surfaces to determine the chronological order of basin filling. The use of a sequence-stratigraphic approach for the interpretation of outcrops, well log data, and seismic reflection profiles with different resolutions and penetrations enable the correlation of areas characterized by heterogeneous data sets. Here, the sequence-stratigraphic approach was applied in the complex area of the Campania Volcanic Zone. The study was conducted by interpreting seismic reflection profiles, well logs, and outcrops, and 3-D modelling of geological surfaces was performed using Kingdom® software (copyright IHS). The results include the discovery of buried volcanic units, the reconstruction of regional geological cross-sections, the construction of a coherent chronostratigraphic framework, and the establishment of stratigraphic relationships between different volcanic fields. This study defines a complete volcanic evolution of the Campania Volcanic Zone, identifies the abrupt changes in the sedimentary environments and, consequently, individuates the volcano-tectonic subsidence events. As a result, the Quaternary stratigraphy of the volcanic events is able to be updated.

A detailed integrated stratigraphic framework for the last 40 ka in the eastern Tyrrhenian Sea (central Mediterranean) was obtained through quantitative analyses of planktonic foraminifera assemblages, tephrostratigraphical studies and δ18O measurements on the basinal CET1 cored succession. Relative abundance fluctuations in the planktonic foraminifera assemblages allowed the identification of nine known eco-biozones and several bioevents recognized in the Tyrrhenian area and that are useful for correlations between Mediterranean marine records. Compositional changes in the planktonic foraminifera assemblages together with variations in the oxygen isotope record allowed us to detect the major climatic global fluctuations and some of the minor events that occurred during the investigated time interval. A total of 12 visible tephra layers and cryptotephras have been recognized and correlated with their volcanic sources and/or with known explosive events of Campanian and Sicilian–Aeolian volcanoes. A stratigraphic relationship between foraminiferal and climatic events and tephra layers has been highlighted. For the first time ecostratigraphic and tephrostratigraphic methods were combined to obtain a detailed integrated stratigraphy for the last 40 ka in the Tyrrhenian area. The achieved stratigraphic framework provides a useful stratigraphic reference record for the investigated area.

The detailed stratigraphic analysis of synkinematic stratal architectures permits the calculation of fold uplift rates and the reconstruction of fold kinematics. This approach was applied to active folds in the Bay of Pozzuoli, eastern Tyrrhenian Sea. This area features late Quaternary volcanism, shallow magmatic intrusions, and transtensional tectonics. Seismostratigraphic analysis of synkinematic strata is constrained by a physical correlation to an already established stratigraphic succession in the neighboring Campi Flegrei and by tephra layers in a gravity core located in Pozzuoli Bay. A stratigraphic resolution in thousands of years was established. Structural and stratigraphic analyses yield quantitative data on the timing of fold inception, kinematics, and the amount and rates of uplift. The folds extend over ∼2 km, and display a curved axial pattern and wedge-shaped packages of synkinematic strata. The rate of fold uplift ranges from 1 to 20 mm/yr. The structures feature limb rotation kinematics and decreasing uplift rates. The uplift rates and geometry of the Pozzuoli Bay folds suggest that they are of tectonic origin and are a product of detachment folding. Their limited longitudinal extent and arcuate axial trends are compatible with an east-trending left transtensional shear zone that was active along the eastern Tyrrhenian Sea during the late Quaternary. A relative sea-level curve was calculated for an anticline culminating in the city of Pozzuoli. This relative sea-level curve highlights the relationship between the deformation timing and the genesis of related abrupt changes in sedimentary facies and erosional surfaces.

High-resolution seismic reflection data are used in the identification of the stratigraphic succession filling Naples Bay, a tectonically active half-graben located in the extensional margin of the eastern Tyrrhenian Sea. The architecture of the basin infill is characterized by fourth-order depositional sequences correlated to Quaternary eustatic oscillations. These depositional sequences form aggrading and prograding stacking patterns bounded by tectonically enhanced unconformities. The changes that the stacking patterns undergo record variations in accommodation space rates. These variations are a result of the tectonic subsidence produced during the evolution of the half-graben.

The structural and stratigraphic interpretation of high-resolution seismic reflection profiles permitted the reconstruction of the tectonics and basin architecture of the Bay of Naples from shelf-slope to deep basin areas. The Bay of Naples half-graben experienced extensional tectonics related to the activity of NE-trending normal faults during the Middle Pleistocene. The half-graben displays asymmetric and multiple fault segments linked by relay zones. The basin infill is made up, from old to young, of an unconformity-bounded unit and seven fourth-order depositional sequences. The oldest unit marks incipient fault activity. Increases of the fault slip rates gave rise to the formation of a tectonically-enhanced unconformity on the shelf and coeval thick debris flows in the deep basin. In the shelf-slope area the fourth-order depositional sequences form a trangressive–regressive cycle. The transgressive trend is linked to fault activity, whereas the regressive trend recorded tectonic stability.

By means of information technology, 3D digital geologic models are increasingly the best methods of constraining interpretations of geology at depth. Visualization in three dimensions has allowed us to develop solutions that explain the stratigraphic and structural complexity of the Campania margin of the Eastern Tyrrhenian Sea, especially the lateral relationships among volcanoes and underlying normal faults. Using seismic and sequence stratigraphy and structural geology approaches in a dedicated GIS environment, we interpreted a seismic grid and investigated a subsurface volcanic field in Gaeta Bay (off Campi Flegrei) located within the Campania margin. The Gaeta Bay basin fill is characterized by several volcanic units that were analyzed using 2D structure contour maps and isochron maps. These volcanoes are comparable in size to the edifices of Campi Flegrei, Vesuvius, and the submerged volcanoes of the Bay of Naples. Their age spans from the Lower Pleistocene for the isolated V0 volcano sited in Central Gaeta Bay to 0.4–0.1 Ma for the volcanic field of southern Gaeta Bay. The study of the interplay between volcanic units and faults allowed us to distinguish (1) the oldest fault buried by the Lower Pleistocene V0 volcano in Central Gaeta Bay; (2) a normal fault swarm NE–SW that in the Middle Pleistocene gave rise to a half-graben filled by the V1–V5 volcanic field in southern Gaeta Bay; and (3) post-0.4 Ma normal faults that downthrow the V1 and V3 volcanoes. We correlated the >1,500-m-thick Late Quaternary volcanoes of southern Gaeta Bay to the buried lava volcanoes interlayered with volcanoclastic deposits drilled at Campi Flegrei geothermal wells.

Vesuvius is an active volcano that has been affected by late Quaternary lateral collapses and tectonic faults. Cryptodomes and two debris avalanche, 18. ka-old DA1 and 3.5. ka-old DA2, were previously documented off Vesuvius and for the younger avalanche a link between onshore and offshore stratigraphy was reconstructed. The interpretation of seismic reflection profiles off Vesuvius, borehole stratigraphies, onshore and geomorphological data allowed to recognise the relationships among debris avalanches, criptodomes and faulting.Stratigraphic data reveal a remarkable difference between the architecture of the northern and southern volcano sectors that is compatible with the occurrence of the DA1 debris avalanche in the southern volcano sector. A contour map and a three-dimensional model of a surface merging the morphology of the top of the Somma lavas, in the northern volcano sector, with that of the top of the DA1 debris avalanche, in the southern volcano sector, were reconstructed. We present a new lateral collapse model of Vesuvius Volcano and document the relevance of inherited tectonic faults in guiding collapse geometry. It is possible that the SW-directed collapse (DA1) was driven towards the hangingwall blocks of NW-SE normal faults, while the propagation of the W-directed collapse (DA2) can be ascribed to the activity of the E-W strike-slip fault. Because of their distal location a minor role of cryptodome intrusion on collapses of Vesuvius can be postulated. The detailed analysis of substrate and edifice structure presented here establishes clear connexion between substrate tectonics and lateral collapse. This approach broadens the horizons of volcanic hazard assessment of Vesuvius. © 2011 Elsevier B.V.