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Il gruppo di geofisica dell'Istituto per l'Ambiente Marino Costiero del CNR, coordinato dal dott. Vincenzo Di Fiore, ha eseguito nello specchio d'acqua del "Porticciolo della Tonnara" antistante alla sede CNR-IAMC di Capo Granitola (TP) un test di sismica marina multicanale. Il team ha eseguito nei giorni 10 e 11 ottobre 2012 le operazioni di acquisizione di 4 profili sismici, di cui tre seriati, al fine di ottenere dati di tomografie sismiche a rifrazione elaborati mediante tecniche 2D e 3D. L'indagine geofisica, che ha interessato la fascia batimetrica compresa tra -2m e -5m, ha previsto il posizionamento del cavo geofonico d'acquisizione (bay-cable) direttamente sul fondale del porticciolo allo scopo di valutare sia i limiti che le potenzialità del metodo, ma anche per definire i parametri di comportamento e i caratteri strutturali dei depositi marini recenti e di età quaternaria presenti nell'area. La sperimentazione di tale tecnica, oltre a consentire l'acquisizione dei dati anche in termini di primi arrivi e di onde superficiali, ha permesso di elaborare modelli di velocità bidimensionale delle onde P ed S. Attraverso l' analisi del campo di variabilità , sono state dedotte utili informazioni sulla struttura del fondo mare sia in termini di geometrie che di caratteristiche elastiche del mezzo indagato.

A detailed carbon-isotope study has been carried out on a Santonian (Upper Cretaceous) carbonate platform succession which crops out at Monte Sant’Erasmo (southern Italy). Previous cm-scale studies on this succession have shown that high-frequency eustatic changes, due to Earth’s orbital fluctuations, controlled the hierarchical organization of the depositional and early diagenetic features in elementary cycles, bundles (groups of 3-5 elementary cycles) and superbundles (groups of 3-4 bundles). While the elementary cycles, which correspond to single beds, suggest a control due to the Earth’s precession, the bundles and superbundles record the short- (~100 kyr) and long- (~400 kyr) eccentricity periodicity respectively. The ä13C signal of the Monte Sant’Erasmo succession is cyclic in nature and may be considered to be a reliable proxy of the sedimentary evolution (and related sea-level history) of the analyzed sequence. The carbon-isotope cyclicity is recorded at bundle and superbundle level, but it is not evident at the scale of the elementary cycles, at least with the sampling interval used in this study. Spectral analysis of the ä13C record shows two main peaks corresponding to the short- and long- eccentricity periodicity, while the precession signal is not evident in the power spectrum. In addition, lithofacies analysis shows that in each bundle (and superbundle) higher C-isotope values occur in sediments characterized by marine cements, while lower values are normally found in more restricted deposits overprinted by early meteoric diagenesis. Early diagenesis, driven by periodic sea-level fluctuations, developed either in shallow-subtidal (marine diagenesis) or in subaerial-exposed (meteoric overprint) sedimentary environments and directly influenced the carbon-isotope signature. As a consequence, the ä13C record at Monte Sant’Erasmo reflects high-frequency climatic oscillations controlling both environmental and early diagenetic changes. The long-term isotopic record is similar to that of contemporaneous pelagic sections in England and elsewere in Italy. It is concluded that the ä13C signature of shallow-water carbonates, like those of Monte Sant’Erasmo, offers great potential for correlation with coeval sections, including those of the pelagic realm.

A high-resolution, integrated stratigraphic framework (stable isotope stratigraphy, standard calcareous nannofossil and foraminiferal biostratigraphy, magnetostratigraphy) together with geochemical and rock magnetic properties analyses of a complete and well-preserved succession at Contessa Valley (Gubbio, central Italy) have offered an excellent opportunity to identify and constrain the Palaeocene to early Eocene hyperthermals and carbon isotope excursions (CIEs). In addition, we provide the first evidence in the Tethys Ocean of CIEs, previously identified in the Pacific, Atlantic and Southern Oceans, highlighting their global significance and of some unknown CIEs. Their characteristics are compared with those reported for deep-sea cores and other land-based sections to test whether the signature associated with CIEs documented in our composite section might give evidence for tracing them over wider areas. The Contessa composite section thus represents a reference succession also for insight into the magnetobiochronostratigraphy and the magnitude of early Palaeogene hyperthermals and CIEs.

In this paper, we present an overview of the Palinuro volcanic complex, in order to have a general outline of the main studies carried out on this seamount. The morphobathymetric studies show that the Palinuro volcanic complex rises from 3000 to 84 m b.s.l., extending about 55 km in the N100oE and 25 km in the N-S direction. The volcanic complex consists of several superimposed volcanic edifices that are basally connected to form a continuous volcanic ridge. Morphological evidence and magnetic data highlight the fact that the seamount is set on the northern edge of the Marsili Basin at the border between the oceanic basin and the continental shore. The presence of volcanic cones in the central sector, one of which shows a pronounced rim not obliterated by erosional events, the major amplitude of the magnetic anomalies with respect to the other sectors and the age of the products sampled on the summit, suggest that this sector is the youngest of the volcanic complex. Morphostructural, hydrothermal and magnetic data suggest that the south-eastern sector of the seamount could be active. The main fault affecting the summit (N65oE) and the E-W deepseated, strike-slip fault system, where the formation of the volcanic complex is hypothesized, may represent the expression of two tectonic lineaments on the seamount, E-W and NE-SW striking, of the Calabrian Arc.

Black shales ad alto potenziale petrolifero, alternati ritmicamente a marne e argilliti, affiorano in associazione con Argille Varicolori (Cretaceo-Paleogene) nei pressi di Novara di Sicilia (Monti Peloritani, Sicilia nord-orientale) costituendo l’espressione sedimentaria di un evento anossico con diffusione globale (OAE2), riferibile al Cenomaniano superiore. I depositi corrispondenti a tale evento sono individuati come “Livello Bonarelli”. In detta successione, le alternanze black shales-marne-argilliti si estendono per uno spessore di circa 11 metri passando verso il basso ad alternanze irregolari di calcari marnosi, marne chiare, marne scure, argilliti e calcareniti (spessore ca. 9 m) che presentano l’intercalazione di un solo orizzonte di black shale. Le caratteristiche petrografiche e geochimiche dei black shales (una millimetrica laminazione perfettamente preservata, abbondante e diffusa pirite in cristalli minuti, alte percentuali di TOC, valori negativi di Mn* e alti V/(V+Ni), accoppiati ad abbondanti radiolari e alti valori del rapporto Si/Al) offrono testimonianza di un ambiente di deposizione caratterizzato da condizioni di estremamente bassa disponibilità di ossigeno nelle acque di fondo associata ad elevata produttività delle acque di superficie. I traccianti geochimici di condizioni redox suggeriscono che le marne e le argilliti della parte inferiore della sezione segnano l'instaurarsi di condizioni disossico-anossiche che successivamente evolvono verso condizioni anossico-euxiniche, in coincidenza con l'aumentata frequenza nella deposizione di black shales. Una comparazione con depositi del "Livello Bonarelli" affioranti in altre zone d'Italia (Appennino Umbro-Marchigiano e Prealpi Bellunesi) discrimina i black shales studiati per alti contenuti di smectite, bassi valori del rapporto K/Al e limitati contenuti di Ba. Organic-rich black shales rhythmically alternating with mar stones and mudstones crop out - in association with the Unit of Varicolourec Clays (Cretaceous-Palcogene) - in an area near the town of Novara di Sicilia (Pelorilani Mountains, northeastern Sicily). These deposits, belonging to the Upper Cenomanian, are identified as "Livello Bonarelli" representing the sedirr entary expression of the anoxic event OAE2. The alternances (about 11 m thick) pass downwards to more irregular alternances (about 9 m thick) of marly limestones, light marlstones, dark marlstones, mudstones, and calcarenites with only one black shale horizon intercalated. Geochemical and petrographic features of the black shales (a well preserved mm-lamination, common disseminated pyrite in very small crystals, high TOC percentages, negative values of Mn* and very high values of V/(V+Ni), together with abundant radiolarians and high values of the Si/Al ratio) identify a depositional environment characterized by very poor oxygen levels associated to high productivity of near-surface waters. Geochemical tracers of paleoredox conditions suggest an evolution from dysoxic-anoxic conditions, during the deposition of marlstones and mudstones from the lower part of the section, towards anoxic-euxinic conditions in coincidence with the enhanced frequency of black shale layers. A comparison with some deposits of the Livello Bonarelli cropping out in other areas in Italy discriminates the black shales studied for their high smectite proportions, low values of K/Al ratio and limited Ba values.

Foraminifera are the most abundant marine protozoa. They show high biodiversity and abundance as an effect of their different ecological requirements. They may respond to environmental changes, leading to high production of specimens under favourable environmental conditions and to their disappearance under strongly unfavourable conditions. This paper represents a detailed investigation carried out on the benthic foraminiferal assemblages, in the highly contaminated marine sediments of the Naples Harbour (southern Campania).The aim of the research is to assess the response of foraminifera to organic and inorganic pollution. Combined use of multivariate canonical, cluster and principal component analysis provided an appropriate approach to explore the role played by contaminants (Heavy metals, PAHs, VOCs, TRPHs, PCBs) and physical parameters (grainsize, pH, Eh, TOC) on the spatial distribution of the benthic foraminifera. Obtained results provide evidence for a high and systematic non-linear response of the biota to the effects of the different pollutants. The reduced number of specimens per sample, their small dimensions and low diversity, testify the negative effects of a highly contaminated environment. In particular the results underline an important effect of the VOC on the distribution of some species, but also demonstrate that any kind of oversimplification would cancel the strong complexity of the biotic response to combined effects of different contaminants.

Climate has been acknowledged as one of the main driving factors behind human development and in turn human activity may cause strong changes on marine ecosystems. Coastal areas represent very useful marine sedimentary archives to investigate the potential effects of human impact on shelf marine ecosystems. The high-resolution investigation presented here of a southern Tyrrhenian marine record from the continental shelf of the Salerno Gulf provides an unprecedented opportunity to study the main natural and human impact that have occurred in this area during the last five centuries. Evidence of an important turnover between carnivorous and herbivorous opportunistic planktonic foraminfera species is recorded after the Maunder event. In addition, after 1940 AD, a strong increase in the distribution pattern of the Globigerina bulloides species combined with a sudden increase in the abundance pattern of the benthic foraminifer Bulimina aculeata, and evident enhancement of benthic and planktonic foraminifera (as number of specimens per gram of dry sediment) can be directly associated to the effects of the construction of the Sele River dam (1934 AD).

Seventeen parent polycyclic aromatic hydrocarbons (PAHs) and 38 congeners of polychlorinated biphenyls were measured at five different sediment depths (between the surface and ~300 cm below the seafloor) at 160 sites in Naples harbour. Total PAH (£PAH) and PCB (£PCB) concentrations ranged between 0.012-21.73(-)nd 0.001-0.222 mg kg(-1), respectively. For PAHs, an evident and progressive decrease in concentration with depth documents the effects of a more intense anthropic impact of this group of pollutants in the recent period. A selected number of PAH isomer pairs (phenanthrene/anthracene, fluoranthene/pyrene and benzo(a)anthracene/crysene) were used to distinguish between contaminants of pyrolitic and petrogenic origin. More than 90% of PAHs present at the different depths of the studied sediments indicate pyrolitic industrial origins. On the other hand, relatively high concentrations of three- and four-ring PAHs suggest a limited contribution of vehicular emissions to the contamination of sediments. An unexpected and systematic increase of £PCB concentration, exceeding values approved by international regulations, was found in the studied sediments, testifying to the uncontrolled discharge to the studied area from industrial and commercial activity on nearby land. Ecotoxicological risk levels calculated for PAHs suggests a relatively elevated level of toxicity in surface sediments decreasing with depth and very low toxicity values associated to PCB toxicity.

International audience

We propose a detailed investigation on the distribution patterns of the benthic foraminiferal assemblage and their predominant species in the highly contaminated marine sediments of the Naples harbour. Combined use of multivariate canonical, cluster and principal component analysis in a proper geostatistic framework provided an appropriate approach to explore the role played by a number of contaminants (heavy metals, polycyclic aromatic hydrocarbons, volatile organic compounds, heavy hydrocarbons, PCBs) and different physical parameters (grain size, pH, redox potential, total organic carbon) on the spatial distribution of the benthic foraminiferal assemblage and its single species. Obtained results provide evidence for a high and systematic non-linear response of the biota to the effects of contamination of the different classes of pollutants. The reduced number of specimens per sample, their small dimensions and low diversity, testify the negative effects of a highly contaminated environment. For this reason, it appears very difficult to clearly identify a differential sensitivity of different benthic species to single classes of contaminants. In particular, in addition to a number of case studies which invoked a key role of the heavy metals in the control of the distribution patterns of the benthic foraminifera in the marine environment, the results presented here underline an important effect of some classes of organic compounds (particularly the volatile organic compounds) on the distribution patterns of the benthic assemblage. However, the obtained results demonstrate that any kind of oversimplification would unquestionably cancel the strong complexity of the biotic response to combined effects of different coexisting contaminants.