Search

The Latest Danian Event (LDE, ~ 62.2 Ma) is characterized by global changes in the carbon cycle as indicated by two negative δ13C excursions of up to ~ 1‰. These δ13C shifts are accompanied by a 2–3 °C warming of both surface and deep waters based on benthic and planktic foraminiferal δ18O measurements, and the LDE has, thus, been considered as a so-called hyperthermal event. The event lasted for 200 kyr and has been identified in various ocean basins and shallow marine settings. Here, we present a compilation of data from three deep-sea cores covering the Pacific, North and South Atlantic oceans as well as a southern Tethyan shelf section to document the response of planktic foraminifera assemblages to ocean warming. In all studied successions, we observe the disappearance of the planktic foraminifer genus Praemurica on a global scale that took place close to the onset of the LDE. Moreover, on the long run, praemuricids were contemporaneously replaced by morozovellids. Both the decline of Praemurica and a temperature increase started between 200 and 260 kyr before the LDE onset and were punctuated by the LDE itself. In this paper, we propose two mechanisms that have controlled the environmental changes associated with this event, (1) increased activity of the North Atlantic Igneous Province acting on long time-scales, and (2) changes of orbital parameters resulting in insolation changes on shorter time-scales. In contrast to a proposed muted benthic foraminiferal response, the planktic community has been substantially impacted by the LDE as indicated by changes in planktic foraminifera faunas and calcareous nannofossils. Finally, our quantitative and conventional approaches identifying stratigraphically important planktic foraminifera datum levels justify a revision of the upper Danian to lower Selandian planktic foraminifera biozonation., Deutsche Forschungsgemeinschaft, KU Leuven http://dx.doi.org/10.13039/501100004040, Projekt DEAL

Gli autori illustrano i risultati di 30 anni di indagini archeologiche e geomorfologiche nell’Alta Valtiberina toscana (Arezzo) effettuate dalle Università di Siena e di Firenze. Le ricerche sono state portate avanti con un approccio multidisciplinare in modo da ricostruire le caratteristiche del territorio, dal Paleolitico all’età del Ferro, dal punto di vista culturale e paleoambientale. Viene proposta una sintesi integrata dei dati e delle attuali conoscenze sulla pre-protostoria della valle., The authors illustrate the issues of thirty years long archaeological and geomorphological studies in the Upper Tiber River basin (Tuscany) by the Universities of Siena and Firenze; the researches have been carried out with a multi-disciplinary approach to study the human and physical characteristics of the territory from the Palaeolithic to the Iron age; cultural aspects and environmental reconstruction have been integrated to provide a synthesis of current knowledge on the pre-protohistory of the Valley., IpoTesi di Preistoria; Vol 3, N° 1 (2010); 1-26

Sr-Nd isotopes were applied for the first time to the study of several moss samples from a transect stretching through Romagna from the Apennines to the Adriatic sea coast. The isotopic data suggest that the mosses uptake Sr and Nd via atmospheric depositions from both marine carbonates and old siliceous crustal rocks. Anthropic pollution cannot be precisely evaluated because of the lack of univocal isotopic signature of the sources., Les isotopes du Sr et Nd ont été appliqués pour la première fois à l’étude des échantillons de mousses pris en Romagne le long d’une section de la côte adriatique aux Apennins. Les données isotopiques suggèrent que les mousses captent Sr et Nd de la poussière atmosphèrique par deux sources, les carbonates marins et les roches de la croûte siliceuse. La pollution anthropique ne peut pas être évaluée certes, car elle n’a pas de signatures isotopiques typiques., Gli isotopi dello Sr e del Nd sono stati applicati per la prima volta allo studio di campioni di muschio prelevati da un transetto attraverso la Romagna esteso dal mare adriatico agli Appennini. I risultati suggeriscono che i muschi prendono Sr e Nd tramite la polvere atmosferica da due sorgenti rappresentate dai carbonati marini e dalle rocce silicatiche crostali. L’inquinamento antropico non può essere valutato con certezza perché non è caratterizzato da parametri isotopici univoci., EQA - International Journal of Environmental Quality; Vol 3 (2010); 9-14

The Sr-isotope ratios of several samples from a natural and an agricultural soil from Ravenna were determined using aqua regia and the two-step sequential extraction. Results indicate that the two-step extraction can provide the researcher with wider and more precise information on Sr sources, thus being a more suitable methodology for achieving scientific goals than the aqua regia extraction. Lastly, the extracts of hydrochloric acid and aqua regia display similar ranges of δ87Sr, indicating that the two procedures provide comparable information on Sr sources., Les rapports isotopiques du Sr ont été déterminés dans les échantillons d’un sol naturel et d’un autre agricole de la zone de Ravenne en utilisant l’aqua regia et l’extraction séquentielle. Les résultats indiquent que l’extraction séquentielle peut fournir une information plus large et plus détaillée sur les sources du Sr. Elle représente donc une méthodologie plus adaptée aux buts scientifiques que l’extraction avec aqua regia. Enfin, les extraits avec aqua regia et acide chlorhydrique fournissent des valeurs comparables de δ87Sr, indiquant que les deux procédures donnent des informations analogues sur les sources de Sr., Sono stati determinati i rapporti isotopici dello Sr di parecchi campioni di un suolo naturale e uno agricolo della zona di Ravenna usando aqua regia e l’estrazione sequenziale. I risultati indicano che l’estrazione sequenziale può fornire una più ampia e puntuale informazione sulle sorgenti dello Sr, essendo quindi una metodica più adatta a conseguire gli scopi scientifici di quanto non sia l’estrazione con aqua regia. Infine gli estratti in aqua regia e acido cloridrico forniscono valori simili di δ87Sr, indicando che le due procedure danno informazioni analoghe sulle sorgenti dello Sr., EQA - International Journal of Environmental Quality; Vol 4 (2010); 7-14

The Sr isotopic compositions of 11 wines from Romagna were determined with the aim of providing a new parameter to track the origin of these wines and serving for better trading. The 87Sr values measured ranged narrowly from -0.07 to +0.33 permil, in agreement with the provenance of the parent grapes from an area characterized by substantial uniformity of soil composition. However, so far, it is possible to make a preliminary distinction of the Sangiovese wines from the other wines analyzed because the former contain slightly more radiogenic Sr. This may reflect the different soil geology of vineyards, as the Sangiovese wines are made from grapes mainly growing on flysch soils, while the other wines are from grapes growing on sedimentary and alluvial Pliocene-Quaternary soils. The comparison of the data from Romagna wines with those of other Italian regions shows the potential of the 87Sr to characterize most of these products. However, the data are ambiguous for distinguishing the wines from vinyards growing on similar lithologies, i.e. soils developed on Late Cenozoic sedimentary rocks. The application of Sr isotopes may be a promising tool for setting the fingerprints of wines when combined with other isotopic and chemical parameters., La composition isotopique du Sr a été mesurée dans 11 vins de Romagne, parce que la détermination de ce paramètre peut être utile à tracer l’origine des produits pour une meilleure commercialisation. Les 87Sr mesurés se sont avérés homogènes au sein d'une faible amplitude de valeurs (-0.07 et +0.33 o/oo), en accord avec la provenance des raisins d’une zone caractérisée en grande partie par l’uniformité des sols. On peut distinguer de façon préliminaire, les vins Sangiovese des autres, parce que ces vins-ci contiennent plus de Sr radiogénique. Cela peut être expliqué par la différente composition géologique des sols, car les raisins de Sangiovese poussent surtout sur sols de flysch et, au contraire, les autres vins proviennent de terrains sédimentaires du Pliocène-Quaternaire. En comparant les données isotopiques des vins de Romagne et d’autre régions italiennes, il semble possible que le 87Sr soit un élément distinctif de la plus grande partie des vins, mais non de tous. Mais les données isotopiques sont ambiguës pour distinguer les vins de raisins développés sur sols issus de lithologies semblables, comme les roches sédimentaires du Cénozoïque supérieur. L’application des isotopes du Sr peut être un outil favorable pour définir les caractéristiques des vins, en conjonction avec d’autres paramètres isotopiques et chimiques., È stata determinata la composizione isotopica dello Sr di 11 vini della Romagna, perché la determinazione di questo parametro può essere utile a tracciare l’origine del prodotto per una migliore commercializzazione. I δ87Sr misurati sono risultati sostanzialmente omogenei, variabili tra -0,07 e +0.33 per mille, in accordo con la provenienza delle uve da un’area caratterizzata da sostanziale uniformità dei suoli. E’ comunque possibile in via preliminare distinguere i vini Sangiovese dagli altri analizzati perché i primi contengono Sr leggermente più radiogenico. Ciò può riflettere la differente geologia dei suoli, perché le uve del Sangiovese crescono prevalentemente su terreni flisciodi, laddove le uve degli altri vini si sviluppano generalmente su suoli sedimentari e alluvionali di età pliocenica-quaternaria. Inoltre dal confronto dei dati isotopici dei vini della Romagna e di altre regioni italiane si evince la possibilità che il δ87Sr sia un parametro distintivo, sebbene non in tutti i casi. Infatti i dati isotopici mostrano ambiguità per vini di uve che crescono su suoli sviluppatisi su simili litologie, cioè rocce sedimentarie tardo-cenozoiche. Tuttavia è possibile che l’applicazione degli isotopi dello Sr possa essere un promettente strumento di definizione della provenienza dei vini, in associazione con altri parametri isotopici e chimici., EQA - International Journal of Environmental Quality; Vol 7 (2011); 41-48

The Sr/Ca ratios and Sr-isotope ratios of bulk samples and acetate extracts from a soil profile developed on Pliocene marine clays near Radicofani, in southern Tuscany, were determined. The uniform Sr/Ca ratios in the soil indicated a uniform distribution of the two elements throughout the profile. In contrast, the lower Sr/Ca ratios of acetate extracts from the upper horizons of the soil suggest preferential removal of Sr relative to Ca, perhaps by the plants. These latter seem to accumulate more Sr than Ca during their lifetime. The δ87Sr of acetate extracts suggests that bulk Sr is provided by the calcite of the Mesozoic-Cenozoic sedimentary formations of southern Tuscany. A minor source of Sr, although subordinate, is represented by clastic albite. A grass sample growing on the soil contained the Sr uptaken from both sources., Les rapports Sr/Ca et les isotopes du Sr ont été déterminés dans des échantillons de sol et les fractions extraites avec l’acétate d’ammonium, d’un profil développé sur les argiles marines du Pliocène près de Radicofani, dans la Toscane méridionale. Les rapports uniformes Sr/Ca du sol indiquent une distribution uniforme des deux éléments le long du profil. Par contre, les rapports plus faibles des fractions acétate mesurés dans les horizons supérieurs du sol suggèrent un retrait préférentiel éloignement du Sr, probablement par la végétation. Il semble que les herbes accumulent plus Sr que de Ca pendant leur vie. Les valeurs de δ87Sr des fractions acétate suggèrent que la plupart du Sr est fournie par la calcite dérivée des formations sédimentaires mésozoϊques et cénozoϊques de la région. Une source mineure de Sr est représentée par l’albite clastique. Un échantillon d‘herbe ayant poussé sur le sol contenait du Sr dérivé de ces deux minéraux., Sono stati determinati i rapporti Sr/Ca e i rapporti isotopici dello Sr in campioni di suolo e negli estratti d’acetato di un profilo sviluppato sulle argille marine plioceniche presso Radicofani, nella Toscana meridionale. I rapporti uniformi Sr/Ca del suolo indicano una distribuzione uniforme dei due elementi nel profilo. Al contrario, i rapporti più bassi misurati nelle frazioni d’acetato degli orizzonti superiori del suolo suggeriscono l’allontanamento preferenziale dello Sr, probabilmente ad opera della vegetazione. Sembra che le erbe accumulino più Sr di Ca durante la loro vita. I valori di δ87Sr degli estratti d’acetato suggeriscono che la maggior parte dello Sr deriva dalla calcite delle formazioni sedimentarie meso-cenozoiche della regione. Una sorgente minore è costituita dall’albite clastica. Un campione di erba che cresce sul suolo contiene Sr derivato da ambedue i minerali., EQA - International Journal of Environmental Quality; Vol 5 (2010); 7-14

The Site of Community Importance of the Pineta S. Vitale, bordered by the Pialassa Baiona lagoon system, is submitted to increasing deterioration due to a subsiding phenomenon, groundwater salinization and contamination from the industrial sites of Ravenna. Within a multidisciplinary research project, evaluation of the background level of Rare Earth Elements (REE, not regulated at present, but potentially harmful to human health) and the characterization of processes which control their migration and retention were performed to contribute to the knowledge on the present environmental quality of the Ravenna area. Concentrations of total and dissolved elements were determined in 40 water samples comprising surface waters, soil waters, shallow and deep groundwater. Dissolved major and minor components generally showed increasing concentrations from West to East (i.e. towards the sea) and appeared mostly derived from a marine source. Marked correlations between dissolved ΣREE and Al and Fe concentrations in the filtered fraction, La Pineta de S. Vitale, site d’intérêt de la Communauté Européenne, située au bord du système lagunaire de la Pialassa Baiona, se détériore de plus en plus à cause des phénomènes de subsidence, de salinisation des aquifères, ainsi que des processus résultant de la contamination par la zone industrielle de Ravenne. Dans le but de contribuer à la connaissance des conditions de l’environnement actuelles, à l’intérieur d’un programme de recherche multidisciplinaire, on a évalué le teneur de fond des éléments de Terres Rares (qui sont potentiellement pathogènes mais pas encore régulés par la normative). On a aussi essayé d’évaluer les processus géochimiques qui contrôlent la migration et la rétention de ces éléments. Les concentrations totales et en solution d’éléments majeurs et mineurs ont été analysées dans 40 échantillons sélectionnés parmi les eaux superficielles, les eaux de la zone saturée des sols, les eaux des nappes superficielles et profondes. La plupart des composants montrent une augmentation de la salinité en s’approchant à la mer. Une corrélation linéaire entre les concentrations de ΣREE et celles de Al et Fe dans la fraction filtrée, Il Sito di Interesse Comunitario della Pineta di S. Vitale, al bordo del sistema lagunare della Pialassa Baiona, è soggetto ad un crescente deterioramento dovuto a fenomeni di subsidenza, salinizzazione degli acquiferi e a processi di contaminazione derivanti dalla prospiciente area industriale di Ravenna. Al fine di contribuire alla conoscenza dello stato ambientale attuale dell’area, nell’ambito di un programma di ricerca multidisciplinare, è stato valutato il tenore di fondo delle terre rare (attualmente non regolamentate dalla normativa, ma considerate potenzialmente patogene) e sono stati condotti studi per la valutazione dei processi che controllano la migrazione e la ritenzione di questi elementi. Sono state pertanto determinate le concentrazioni totali e disciolte di un set di elementi in 40 campioni selezionati fra acque superficiali, acque della zona satura dei suoli, acque delle falde superficiali e profonde. I componenti maggiori e minori mostrano un generale andamento crescente spostandosi dall’entroterra verso il mare. E’ stata riscontrata una correlazione lineare fra la concentrazione della ΣREE e le concentrazioni di Al e Fe nelle frazioni filtrate a, EQA - International Journal of Environmental Quality; Vol 1 (2009); 43-50

In the frame of a multidisciplinary project of research on the San Vitale Pinewood ecosystem, north of Ravenna, the Sr isotope study of a soil profile developed on an old coastal dune aiming at detecting the effect of salinization is presented. The Sr isotope ratios of the bulk soil samples decreased significantly from upper (0.717) to lower (0.712) horizons because of the abundant marine salts deposited by the brackish water present in the deep soil. While the main source of Sr in the upper horizons is the silicates, especially the feldspaths contained in the old dune sediments; in contrast, Sr in the lower horizons is significantly also of evaporitic origin (0.707-0.709). This latter is dominantly the strontium bio-available to the plants., Dans le cadre d’un projet multidisciplinaire de recherche sur le processus de salinisation des sols, nous présentons une application des isotopes du Sr à un profil de sol développé sur une ancienne dune côtière dans la Pinède S.Vitale, au nord de Ravenne. La composition isotopique du Sr dans les échantillons du sol tel quel diminue des horizons superficiels (0,717) aux horizons profonds (0,712) par suite de l’abondant dépôt de sels marins par l’eau saumâtre présente dans les horizons inférieurs du profil. Le strontium présent dans les horizons les plus superficiels provient des silicates de l’ancienne dune, en particulier des feldspaths, mais le strontium des horizons inferieurs provient en grade partie aussi du lessivage des évaporites (0,707-0,709). Le strontium biodisponible pour les plantes est surtout dérivé des évaporites., Nel quadro di uno studio multidisciplinare sui processi di salinizzazione che interessano i suoli della Pineta di san Vitale, a nord di Ravenna, viene presentato un esempio di applicazione degli isotopi dello Sr. La sua composizione isotopica nei campioni di suolo tal quale diminuisce significativamente dagli orizzonti superficiali (0,717) a quelli profondi (0,712), a causa della abbondante deposizione di sali marini ad opera dell’acqua salmastra presente nella parte bassa del profilo. Mentre lo Sr presente negli orizzonti superiori del suolo è essenzialmente quello dei silicati dell’antica duna, in particolare dei feldspati, lo Sr degli orizzonti inferiori deriva considerevolmente anche dai sali e minerali evaporitici (0,707-0,709). Lo Sr biodisponibile per le piante è essenzialmente quello derivato dagli evaporiti., EQA - International Journal of Environmental Quality; Vol 2 (2009); 73-77

In a building site located near the historic centre of the city of Bologna (Italy), archaeological and geopedological studies supplemented by chemical and physical analyses of the soil made it possible to identify 17 pedogenic cycles. These cycles, distributed in a continuous chronosequence from Reinassance period back to the Bronze Age, show a persistent anthropogenic presence as demonstrated by the different distributions of P2O5 and CaCO3, by the concentrations of some elements (Cu, Pb, Sn) and by the presence of fragments of charcoal, brick and ceramics, which overall reach the highest values during the Iron Age (Etruscan and Villanovan). According to the WRB taxonomic system, the soil units of the pedogenetic cycles belong to the groups of Anthrosols, Cambisols and Technosols., En concomitance avec l'aménagement d'un important chantier archéologique destiné à la connaissance de la colonisation de l'ancienne cité de Bologne à l'époque étrusque, a été effectuée dans le même site une étude pédologique et stratigraphique avec le but de mettre en évidence la présence humaine aux diverses époques sur une période d'environ trois mille ans à partir de l'âge du bronze. L'examen de facteurs physiques du sol ceux-ci associés à la multi-analyse, a permis de reconstruire une séquence évolutive dans laquelle ont pu être reconnues 17 unités de sol. La concentration significative en Cu, Pg et Sn des sols des périodes Etrusque et Villanovienne ont confirmé l'activité artisanale de ces populations de l'âge du fer. D'après le système WRB, les unités de sols entrent dans trois principaux groupes taxonomiques (Anthrosols, Cambisols et Technosols)., In un cantiere ubicato in prossimità del centro storico della città di Bologna (Italia) gli studi archeologici e geopedologici integrati dalle analisi chimiche e fisiche dei suoli hanno permesso di evidenziare 17 cicli pedogenici. I cicli, distribuiti in cronosequenza continua dal periodo rinascimentale all’età del bronzo hanno mostrato una persistente frequentazione antropica come evidenziato dalla diversa distribuzione di P2O5 e CaCO3, dalle concentrazioni di alcuni elementi (Cu, Pb, Sn) e dalla presenza di frammenti di carbone, laterizi e ceramiche, che raggiungono nel loro complesso i massimi valori durante l’età del ferro (Etruscan and Villanovan). Le unità di suolo dei cicli pedogenetici rientrano, secondo il sistema tassonomico della WRB, nei gruppi degli Anthrosols, Cambisols e Technosols., EQA - International Journal of Environmental Quality; Vol 6 (2011); 1-6

Sr/Ca ratios, and Sr and Nd isotopes, were determined in aqua regia extracts from three urban and agricultural soils from Ravenna. Sr/Ca ratios suggested preferential retention of Sr in the agricultural soils during the weathering of bedrock minerals. Despite of the different land use, the three soils displayed similar isotopic ranges, suggesting common sources for the two elements, likely represented by old marine carbonates and crustal silicates. The Nd isotopes of the urban park topsoil suggest some contamination by the soot of car exhausts., Les rapports Sr/Ca et les isotopes du Sr et du Nd ont été déterminés dans les extraits avec aqua regia de trois sols agricoles et résidentiels dans la zone de Ravenne. Les rapports Sr/Ca suggèrent la rétention préférentielle du Sr dans les sols agricoles pendant l’altération des minéraux. Nonobstant leur utilisation différente, les sols ont des valeurs isotopiques semblables, qui suggèrent des sources communes pour les deux éléments, représentées par d’anciens carbonates marins et des silicates de la croûte terrestre. Les horizons, les plus superficiels du sol du parc urbain sont probablement affectés par une pollution de Nd dérivé des émissions de voitures., Sono stati determinati i rapporti Sr/Ca e i rapporti isotopici di Sr e Nd in estratti di aqua regia di tre suoli interessati da uso agricolo e residenziale della zona di Ravenna. I rapporti Sr/Ca suggeriscono la ritenzione preferenziale dello Sr nei suoli agricoli durante l’alterazione dei minerali. Nonostante il differente uso, i suoli hanno rapporti isotopici simili, suggerendo che Sr e Nd derivano da sorgenti comuni, rappresentate da carbonati marini antichi e silicati crostali. Gli orizzonti più superficiali del suolo del giardino pubblico mostrano una probabile presenza di Nd derivato dalle emissioni di scarico dei veicoli., EQA - International Journal of Environmental Quality; Vol 4 (2010); 53-62

International audience; We investigated the kinematics of the coupled Helminthoid Flysch-Marguareis Unit outcropping in the High Tanaro Valley in order to constraint the tectonic evolution of the Western Ligurian Alps. Field mapping highlights a tectonic pile composed of, from top to bottom: the Marguareis Unit (Briançonnais Domain); the Helminthoid Flysch Unit (Ligurian Domain) and several continentalderived tectonic slices (Chambeuil Slices) showing affinity to the Briançonnais Domain. Each unit recorded different deformation histories represented by pre-, syn-and post-stacking structures. The syn-stacking structures are represented by thrusts and folds, both responsible for the coupling of the units and for their current structural relationships. In other sectors of the Alpine chain previous authors have highlighted similar structural architectures. We maintain that syn-stacking deformation events played a key role in the tectonic evolution of the Western Ligurian Alps.

International audience; This research program, involving French and Italian institutions, aims at understanding how the settling and development of the Etruscan city of Orbetello affected the environmental evolution of its lagoon, and how the evolution of the lagoon affected in turn the economics of Orbetello. In other words, to define how the life of the city has been influenced by its own impact on the lagoon. To achieve this we have followed two lines of research. One is historical, based on the analysis of iconographic, textual and archaeological archives from antiquity to the present day. The other, paleoenvironmental, is based on the analysis of sedimentary archives. The idea is to combine several investigation methods to map the dynamics of sedimentation, by means of geophysical prospecting (imaging of the sedimentary architecture using acoustic profiles) and the study of sedimentary cores. The latter allow the dating of sediments, the analysis of their biological components to reconstitute lagoon palaeoenvironments (ostracods, pollen, dinoflagellate cysts, malacofauna, composition of organic matter), and the analysis of metallic contaminants, highlighting the changes induced by lagoon management and the development of the city.

International audience; This research is part of the PON (Programma Operativo Nazionale) SINAPSIS (SIstema NAzionale Protezione SIti Sensibili), an interdisciplinary project combining archaeological and archaeometric methods. This paper focuses on frescoes from one of the 70 funeral monuments belonging to "Porta Mediana" Necropolis, a very interesting archaeological context located in Cuma, dating back to the first half of the 3rd century BCE. The study provided detailed information on pigments and colors acquired both on untreated and treated (restored) frescoes. Portable colorimetry and chemical-mineralogical (Raman spectroscopy and X-ray powder diffraction-XRPD, respectively) analyses were performed in situ and on collected samples in order to: 1) identify pigments, raw materials and provenance, 2) point out possible color changes caused by conservative treatments and/or weathering. The identified palette is typical of the Roman period; it includes both single and mixtures of two or more pigments to obtain particular hues. Moreover, the identified raw materials, such as red and yellow ochres, green frit and Egyptian blue, clearly highlighted the choice to use raw materials from local sources. The use of expensive coloring materials also suggests that the mausoleum belonged to a family or a group of people with a high social status.

This study presents the first Late Holocene marine pollen record (core ND2) from SE Sicily. It encompasses the last 3000 years and is one of the most detailed records of the south-central Mediterranean region in terms of time resolution. The combined approach of marine palynology and historical ecology, supported by independent palaeoclimate proxies, provides an integrated regional reconstruction of past vegetational dynamics in relation to rapid climatic fluctuations, historical socio-economic processes, and past land-use practices, offering new insights into the vegetation history of SE Sicily. Short-term variations of sparse tree cover in persistently open landscapes reflect rapid hydroclimatic changes and historical land-use practices. Four main phases of forest reduction are found in relation to the 2.8 ka BP event, including the Late Antique Little Ice Age, the Medieval Climate Anomaly, and the Little Ice Age, respectively. Forest recovery is recorded during the Hellenistic and Roman Republican Periods, the Early Middle Ages, and the last century. Agricultural and silvicultural practices, as well as stock-breeding activities, had a primary role in shaping the current vegetational landscape of SE Sicily.

International audience; In the Western Alps, while many P–T constraints are available for the high-grade units, the dataset for the low-grade units located along the westernmost edge of the belt remains scarcer and incomplete. To face these uncertainties, we quantify for the first time the metamorphic peak conditions of the Marguareis Unit, a fragment of European margin (Briançonnais Domain) regarded till now as very-low-grade unit, exposedalong the boundary between Maritime and Ligurian Alps (South-Western Alps), whose deformation history is well constrained. The Marguareis Unit is regarded as a thinned portion of the European continental margin involved in the Alpine collision. Metamorphic peak conditions reconstructed using the chlorite–phengite multi-equilibrium approach on the Eocene siliciclastic deposits indicate that the Marguareis Unit recorded high-pressure and low-temperature conditions during its subduction, accretion and subsequent exhumation into the Alpine wedge.

International audience; Explosive activity preceding the ~40 ka Campanian Ignimbrite (CI) eruption in the Neapolitan volcanic area, Southern Italy, has long been speculated based on the occurrences of widespread tephra layers, with a Campanian geochemical signature, such as the C-22, X-5, and X-6, preserved in Mediterranean Marine Isotope Stage (MIS) 5 sedimentary records. However, previous studies of pre-CI pyroclastic units occurring in close proximity of the Neapolitan volcanoes, including Campi Flegrei, Somma-Vesuvius, Ischia and Procida islands, did not allow a conclusive identification of the near-source equivalents of these tephra markers. Here we present a comprehensive characterization of four pyroclastic units from the Campanian Plain, comprising major and trace element glass compositions, Sr[sbnd]Nd isotopes and 40Ar/39Ar dating. Our data allowed the identification of the medial equivalents of the MIS 5 tephra markers, including the widespread C-22, X-5, and X-6 tephra, and their assignment to previously undocumented Campi Flegrei activity between 109 and 92 ka. In addition to substantially extending Campi Flegrei explosive activity deeper in time, and thus providing the basis for a revaluation of its history, our findings provide new precise radioisotopic dating to better constrain the chronology of the millennial scale climatic oscillations of the MIS 5c-d in the Mediterranean area and possibly on a larger scale.

Co-auteur étranger; International audience; The variability in intensity and style shown by explosive volcanism has been traditionally explained by a complex interplay among melt composition and pre-eruptive volatile content, which modulate magma ascent and conduit dynamics. However, magmas having similar compositions may becharacterized by subtle textural changes affecting magma rheology and eventually explosive dynamics. Here we study five eruptions occurred at Cotopaxi volcano (Ecuador) in the last 2000 years characterized by a small variation in magma composition but spanning a wide range of intensity to investigate how these parameters control variations in eruption dynamics. We combined eruption source parameters (ESPs), obtained from the application of recent models to all the available field data, with new textural data and state-of-the-art conduit dynamics modeling. We found that, despite having variable microlite content and texture, the effect of microlite on magma rheology is partly counterbalanced by variablephenocryst abundance, resulting in a comparable total crystal content. The combination of modeling results with textural data and ESPs suggests that subtle variability in crystal content and magma composition may be accompanied by strong feedback effects among crystallization, changes in melt/ magma viscosity and volatile exsolution, with microlite crystallization resulting in a rapid change of magma rheology and modifications in the explosive dynamics. By combining ESPs with quantitative textural data (i.e. melt normalized vesicle number density) and conduit modeling, we also show how general observed correlations between composition and texture of juvenile products with eruption intensity are not evident when applied to eruptions characterized by a small compositional range.

Melt transport mechanisms have an important impact on the chemical composition of the percolated host rock and the migrating melts. Melt migration is usually assumed to occur at grain boundaries. However, microstructural studies revealed the occurrence of polyphase inclusions along dislocations, subgrain boundaries and microcracks in single mineral grains. The inclusions are interpreted as crystallized melt pockets suggesting that melts can migrate within deformed crystals. Intracrystalline melt migration and diffusive re-equilibration can lead to significant mineral trace element enrichments when associated with dissolution–precipitation reactions. In this contribution, we study a body of replacive troctolites associated with the Erro-Tobbio ophiolitic mantle peridotites (Ligurian Alps, Italy). The replacive formation of the olivine-rich troctolite involved extensive impregnation of a dunitic matrix, i.e. partial dissolution of olivine and concomitant crystallization of interstitial phases. The olivine matrix is characterized by two distinct olivine textures: (i) coarse deformed olivine, representing relicts of the pre-existing mantle dunite matrix (olivine1), and (ii) fine-grained undeformed olivine, a product of the melt–rock interaction process (olivine2). Previous studies documented a decoupling between olivine texture and trace element composition, namely enriched trace element compositions in olivine1 rather than in olivine2, as would be expected from the dissolution–precipitation process. Notably, the trace element enrichments in deformed olivines are correlated with the occurrence of elongated 10 µm size polyphase inclusions (clinopyroxene, Ti-pargasite, chromite) preferentially oriented along olivine crystallographic axes. These inclusions show irregular contacts and have no crystallographic preferred orientation with the host olivine, and the phases composing the inclusions show similar chemical compositions to the vermicular phases formed at the grain boundaries during late-stage reactive crystallization of the troctolite. This suggests that the investigated inclusions did not form as exsolutions of the host olivine but rather by input of metasomatic fluids percolating through the deformed olivine grains during closure of the magmatic system. We infer that strongly fractionated volatile-rich melts were incorporated in oriented microfractures within olivine1 and led to the crystallization of the polyphase inclusions. The presence of intracrystalline melt greatly enhanced diffusive re-equilibration between the evolved melt and the percolated olivine1, in turn acquiring the enriched character expected in neoformed olivine crystals. Intracrystalline melt percolation can have strong geochemical implications and can lead to efficient re-equilibration of percolated minerals and rocks.

The San Salvador volcanic complex (El Salvador) and Nejapa-Chiltepe volcanic complex (Nicaragua) have been characterized by a significant variability in eruption style and vent location. Densely inhabited cities are built on them and their surroundings, including the metropolitan areas of San Salvador (∼2.4 million people) and Managua (∼1.4 million people), respectively. In this study we present novel vent opening probability maps for these volcanic complexes, which are based on a multi-model approach that relies on kernel density estimators. In particular, we present thematic vent opening maps, i.e., we consider different hazardous phenomena separately, including lava emission, small-scale pyroclastic density currents, ejection of ballistic projectiles, and low-intensity pyroclastic fallout. Our volcanological dataset includes: (1) the location of past vents, (2) the mapping of the main fault structures, and (3) the eruption styles of past events, obtained from critical analysis of the literature and/or inferred from volcanic deposits and morphological features observed remotely and in the field. To illustrate the effects of considering the expected eruption style in the construction of vent opening maps, we focus on the analysis of small-scale pyroclastic density currents derived from phreatomagmatic activity or from low-intensity magmatic volcanism. For the numerical simulation of these phenomena we adopted the recently developed branching energy cone model by using the program ECMapProb. Our results show that the implementation of thematic vent opening maps can produce significantly different hazard levels from those estimated with traditional, non-thematic maps.

Co-auteur étranger; International audience; Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100 years. For each type, we elicited relevant eruption source parameters (duration, average plume height, and total tephra mass). We investigated the robustness of these elicited evaluations by deriving probability uncertainties using three expert scoring methods. For Cotopaxi, we considered both rhyolitic and andesitic magmas. Elicitation findings indicate that the most probable next eruption type is an andesitic hydrovolcanic/ash-emission (~ 26–44% median probability), which has also the highest median probability of recurring over the next 100 years. However, for the next eruption at Cotopaxi, the average joint probabilities for sub-Plinian or Plinian type eruption is of order 30–40%—a significant chance of a violent explosive event. It is inferred that any Cotopaxi rhyolitic eruption could involve a longer duration and greater erupted mass than an andesitic event, likely producing a prolonged emergency. For Guagua Pichincha, future eruption types are expected to be andesitic/dacitic, and a vulcanian event is judged most probable for the next eruption (median probability ~40–55%); this type is expected to be most frequent over the next 100 years, too. However, there is a substantial probability (possibly >40% in average) that the next eruption could be sub-Plinian or Plinian, with all that implies for hazard levels.

During the evolution of continental rift systems, extension is thought to progressively focus in-rift to the future breakup boundary while faults along the rift margins progressively deactivate. However, observational constraints on how strain is partitioned between rift axis and rift margins are still lacking. The Afar rift records the latest stages of rifting and incipient continental breakup. Here, we analyzed the recent M W 5.2 earthquake on the Western Afar Margin on March 24, 2018 and the associated seismic sequence of >500 earthquakes using 24 temporary seismic stations deployed during 2017–2018. We show seismicity occurring at lower crustal depths, from ∼15 to ∼30 km, with focal mechanisms and relocated earthquakes highlighting both west-dipping and east-dipping normal faults. We tested earthquake depth using InSAR by processing six independent interferograms using Sentinel-1 data acquired from both ascending and descending tracks. None of them shows evidence of surface deformation. We tested possible ranges of depth by producing forward models for a fault located at progressively increasing depths. Models show that surface deformation is not significant for fault slip at depths greater than 15 km, in agreement with the hypocentral depth of 19 km derived from seismic data for the largest earthquake. Due to the localized nature of deep earthquakes near hot springs coupled with subsurface evidence for magmatism, we favor an interpretation of seismicity induced by migrating fluids such as magma or CO 2. We suggest that deep fluid migration can occur at the rifted-margin influencing seismicity during incipient continental rupture.

International audience; Glacial-interglacial variations in ice volume and sea level are essential components of the Pleistocene global climate evolution. Deciphering the timing of change of these key climate parameters with respect to the insolation forcing is central to understanding the processes controlling glacial terminations. Here we exploit the sensitivity of the Paleo Tiber River (central Italy) to sea-level forced changes in the base level and the frequent occurrence of datable tephra layers in its sedimentary successions to reconstruct the timing of the relative sea-level (RSL) change between 450 and 403 ka, i.e., across the glacial termination (T-V) that marks the transition between Marine Isotope Stage (MIS) 12 and MIS 11. The analysis hinges on new stratigraphic data, tephra geochemical fingerprinting, and 40Ar/39Ar dating from a fluvial section that represents the inland counterpart of the near mouth, coastal aggradational successions of the San Paolo Formation (SPF). Tephra correlation indicates that the morpho-stratigraphic record of the inland section is as sensitive to the sea-level change as its coastal counterparts, which makes it ideal to complement previous RSL reconstructions from the Tiber River catchment basin, thereby providing a more detailed picture of the sea-level history across T-V. Combined sedimentological and morphological proxies of the composed inland-coastal SPF record document the occurrence of two phases of relatively rapid sea-level rise, here interpreted as meltwater pulse (MWP) events. The earlier MWP occurred between ∼450 and ∼445 ka and matches a relatively minor episode of the sea-level rise documented in an existing RSL record, while the younger MWP at ∼430 ka corresponds to the high amplitude sea-level rise that marks T-V. We find that both MWPs coincide with episodes of ice-rafted debris deposition in the North Atlantic (Heinrich-like events) and with attendant Southern Hemisphere warming, plausibly associated with the bipolar seesaw.

The timing, duration and evolution of sea level during the Marine Isotope Stage 5e (MIS 5e) highstand is a subject of intense debate. A major problem in resolving this debate is the difficulty of chronologically constraining the sea level fall that followed the peak of the highstand. This was mainly controlled by ice-sheet dynamics, the understanding of which is relevant for assessing future sea-level behavior due to global warming. Here we use stratigraphical and geochoronological (U/Th dating and tephra fingerprinting) evidence from the Infreschi archaeological cave (Marina di Camerota, Southern Italy) to constrain relative sea level (RSL) evolution during the MIS 5e highstand and younger stages. Uranium-thorium dating of speleothem deposition phases places the maximum highstand RSL at 8.90 ± 0.6m a.s.l., as indicated by the near-horizontal upper limit of Lithophaga boreholes measured for along a ∼3.5 km coastal cliff section. Geochronological data show that RSL fell more than 6 m before ∼120 ka, suggesting a duration of the Last Interglacial highstand significantly shorter than proposed in some previous studies. Modelling shows that the RSL trend predicted by the ICE-5G and ICE-6G ice-sheet simulations is consistent with our data, but requires an additional significant reduction of both Greenland and Antarctic ice sheets to match the height of the local maximum highstand if no correction for tectonics is applied. Reconciling field data and models requires an earlier and likely shorter duration of the MIS 5e highstand. This suggests that our new data can constrain global ice-volume variations during the penultimate deglaciation, as well as glacial inception at the end of the Last Interglacial. According to our chronology, there is no local evidence of higher-than-present-day sea levels after 120 ka.

Processes of crystal-mush remobilization by mafic magma recharges are often related to the outpouring of large volumes of silicic melt during caldera-forming eruptions. This occurred for the Campanian Ignimbrite (CI) eruption (Campi Flegrei, Italy), which produced a voluminous trachy-phonolitic ignimbrite in southern-central Italy about 40 ka ago. We focussed on the proximal-CI deposits at San Martino that are composed of a main sequence of early-erupted, crystal-poor units and a late-erupted (post-caldera collapse) crystal-rich Upper Pumice Flow Unit (UPFU). Detailed micro-analytical geochemical data were performed on glasses and crystals of pyroclasts from these deposits and coupled with Sr-Nd isotopic measurements on glasses. Results show that the CI eruption was fed by two distinct melts for the early-erupted units and the late UPFU, respectively. The glasses of the early-erupted units have negative Eu anomalies and show more evolved compositions and higher Nd isotope ratios than those of the UPFU, which have positive Eu/Eu*. The magmas of the early units formed the main volume of eruptible melt of the CI reservoir, and are interpreted as having been extracted from cumulate crystal-mush without a vertical geochemical gradient within the magma reservoir. The data indicate that the generation of the distinctive UPFU melts involved the injection of a new batch of mafic magma into the base of the CI reservoir. The mafic magma allowed heating and reactivation of the CI crystal-mush by melting of low-Or sanidines (+/− low-An plagioclases), leaving high-An plagioclases and high-Mg# clinopyroxenes as residual phases and a crystal-mush melt, made of 20% of the initial mush interstitial melt (with a composition similar to the early-erupted units) and 80% of sanidine melt. When the mush crystallinity was sufficiently reduced, the mafic magma was able to penetrate into the reactivated crystal-mush, mixing with variable proportions of crystal-mush melt and generating cooler hybrid melts, which underwent further crystallization of high-Or sanidine at variable degrees (10–25%). Finally, possibly a short time before the eruption, the UPFU magmas were able to mix and mingle with the crystal-poor eruptible melts still persisting in the CI reservoir at the time of UPFU emission. We suggest that the complex mechanisms described for the magma evolution feeding the CI eruption may occur whenever a crystal-mush is reactivated by new mafic magma inputs

International audience; We document structural, geochemical, petrological and 40Ar/39Ar geochronological data performed on Variscan eclogites from the Argentera–Mercantour Massif, southwestern Alps. Based on the high-resolution field mapping, we present new eclogite occurrences and discuss the relationships between eclogites and surrounding migmatites. We recognized for the first time preserved eclogite facies assemblages. Trace elements and REE patterns establish that eclogites protoliths are MORBs contaminated by continental crust. Standard thermobarometry and thermodynamic modeling are consistent with P–T values of 640–740 °C for 1.5 ± 0.25 GPa, coherent with paleo-geotherms predicted for warm subduction of oceanic crust. We inter- pret these eclogites as a dismembered cryptic suture zone. 40Ar/39Ar dating on amphiboles yields an age of 339.7 ± 12 Ma for eclogite retrogression under amphibolite facies conditions. All these data are combined to link the Argentera–Mercantour Massif in the tectonic framework of both pre-Mesozoic Alpine basement and European southern Variscides.

International audience; The interest for the environmental, industrial and technological applications of Si-rich zeolites is very high. Among the large-pore zeolites, faujasite is one of the most exploited. The aim of this paper is to obtain detailed structural information on natural and NH4 -exchanged faujasite before using this zeolite for dealumination tests, targeting the realization of large single crystals of allsilica faujasite. As one of the most Si-rich natural samples, faujasite from Sasbach (Na13.64 K0.87 Mg10.46 Ca8.89 Sr0.34 (Al51.95 Si139.57 ) O384 ·272.29 H2 O; space group Fd-3 m; a = 24.6906(2) Å) was chosen for study. Single-crystal X-ray diffraction structural refinements of both natural and NH4 -exchanged samples are reported and discussed. In the natural faujasite sample, almost all the extraframework species could be located for the first time. In the NH4 -exchanged sample the ammonium and water molecule sites were located. Ammonium cations occupy two of the sites occupied by the extraframework species in the original mineral.

International audience; Marine Protected Areas (MPAs) have been proved to effectively protect and restore fish assemblages. There is mixed evidence regarding the effects of MPAs on benthic assemblages, habitat complexity, and how protection might mediate the effects of habitat features (including biotic and abiotic components) on fish assemblages, with very little information concerning temperate areas. Here, our aim is to assess how protection 1) influences benthic assemblages and habitat complexity, and 2) mediates the effects of habitat complexity on fishes.Using non-destructive methods (photosampling for shallow rocky benthic assemblages, and underwater visual census using strip transects for fish assemblages) to characterize benthic and fish assemblages, we sampled 15 Mediterranean locations, each including protected and unprotected sites. In all, we sampled 90 sites, and analyzed 2,760 photos and 800 replicated transects, gathering information on 44 benthic and 72 fish taxa. Abiotic, biotic and synthetic (i.e. combining the previous two) complexity indices have been computed to synthesize habitat features. Overall, whole benthic assemblages did not significantly differ between protected and unprotected conditions, but higher cover of the ecologically important erect algae belonging to the genus Cystoseira sensu lato was recorded within MPAs. Abiotic, biotic and synthetic complexity did not show clear patterns related to protection levels, displaying inconsistent responses between different locations. Our findings highlight that protection has a generally positive effect on fish biomass, this latter variable responding independently of the habitat complexity.Our study, in conclusion, confirms that MPAs can be effective to protect and restore rocky-reef assemblages, highlighting the need for more in-depth exploration of the mechanisms determining the different responses of benthic taxa to protection and how this can influence the associated fish assemblages.

International audience; On October 1st, 2005, Santa Ana volcano (El Salvador) underwent a VEI 3 phreatomagmatic eruption after approximately one century of rest. Casualties and damages to some of the local infrastructures and surrounding plantations were followed by the evacuation of the nearby communities. The analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) infrared data reveals that the main explosion was preceded by a one-year-long thermal unrest, associated to the development of a fumaroles field, located at the western rim of the summit crater lake. By combining space-based thermal flux and ground-based measurements (seismicity, sulfur emissions and lake temperatures), we suggest that the activity observed at Santa Ana between 2004 and 2005 was driven by the gradual intrusion of an undegassed magma body at a very shallow depth. Magma injection induced thermal anomalies associated with sustained degassing from the fumaroles field and promoted the interaction between the magmatic-hydrothermal system and the overlying water table. This process culminated into the VEI 3 phreatomagmatic eruption of October 2005 that strongly modified the shallow structure of the crater area. The subsequent three-years-long activity resulted from self-sealing of the fracture system and by the opening of a new fracture network directly connecting the deeper hydrothermal system with the crater lake. Our results show that satellite-based thermal data allow us to detect the expansion of the high-temperature fumarolic field. This may precede an explosive eruption and/or a lava dome extrusion. In particular, we show that thermal records can be analyzed with other geochemical (i.e. SO2 emissions) and geophysical (seismicity) data to track a shallow magmatic intrusion interacting with the surrounding hydrothermal system. This provides a remarkable support for volcano monitoring and eruption forecasting, particularly in remote areas where permanent ground data acquisition is hazardous, expensive and difficult.

This work studies the thermal stability, heat-induced structural deformations, and dehydration/rehydration dynamics of a synthetic high silica mordenite. It is of special interest because this particular phase has proven to be an ideal host for the encapsulation of several kinds of organic molecules making it a promising scaffold for drug delivery. The dehydration process was followed by thermal analysis, infrared spectroscopy in controlled atmosphere, in situ synchrotron XRPD, and structural refinement. Overall, all the results indicate weak interactions of H2O molecules with the silicatic mordenite framework and evidence the presence of hydroxyl groups with different condensation responses at high temperature. Infrared characterization highlighted how the desorption of adsorbed H2O molecules under degassing is already complete at rT. The unit cell parameters exhibit very slow and almost isotropic changes upon heating. Above 550 °C an increase in slope is observed for all parameters. This corresponds to the marked silanol condensation and consequent framework reassessment observed at this temperature by infrared characterization. Overall cell contractions are 0.67%, 1.18%, and 0.81% for a, b, c, respectively and 2.64% for cell volume. HS-MOR undergoes very moderate T induced deformations, indicating a very rigid and stable framework.

HBr emissions from volcanoes lead rapidly to the formation of BrO within volcanic plumes and have an impact on tropospheric chemistry, at least at the local and regional scales. The motivation of this paper is to prepare a framework for further 3D modelling of volcanic halogen emissions in order to determine their fate within the volcanic plume and then in the atmosphere at the regional and global scales. The main aim is to evaluate the ability of the model to produce a realistic partitioning of bromine species within a grid box size typical of MOCAGE (Model Of atmospheric Chemistry At larGE scale) 3D (0.5∘ × 0.5∘). This work is based on a 1D single-column configuration of the global chemistry-transport model MOCAGE that has low enough computational cost to allow us to perform a large set of sensitivity simulations. This paper uses the emissions from the Mount Etna eruption on 10 May 2008. Several reactions are added to MOCAGE to represent the volcanic plume halogen chemistry. A simple plume parameterisation is also implemented and tested. The use of this parameterisation tends to only slightly limit the efficiency of BrO net production. Both simulations with and without the parameterisation give results for the partitioning of the bromine species, of ozone depletion and of the BrO/SO2 ratio that are consistent with previous studies. A series of test experiments were performed to evaluate the sensitivity of the results to the composition of the emissions (primary sulfate aerosols, Br radical and NO) and to the effective radius assumed for the volcanic sulfate aerosols. Simulations show that the plume chemistry is sensitive to all these parameters. We also find that the maximum altitude of the eruption changes the BrO production, which is linked to the vertical variability of the concentrations of oxidants in the background air. These sensitivity tests display changes in the bromine chemistry cycles that are generally at least as important as the plume parameterisation. Overall, the version of the MOCAGE chemistry developed for this study is suitable to produce the expected halogen chemistry in volcanic plumes during daytime and night-time.

Several detailed studies of the external morphology of the ear region in extinct sloths have been published in the past few decades, and this anatomical region has proved extremely helpful in elucidating the phylogenetic relationships among the members of this mammalian clade. Few studies of the inner ear anatomy in these peculiar animals were conducted historically, but these are increasing in number in recent years, in both the extinct and extant representatives, due to wider access to CT-scanning facilities, which allow non-destructive access to internal morphologies. In the present study, we analyze the extinct ground sloth Glossotherium robustum and provide a description of the external features of the ear region and the endocranial side of the petrosal bone, coupled with the first data on the anatomy of the bony labyrinth. Some features observable in the ear region of G. robustum (e.g., the shape and size of the entotympanic bone and the morphology of the posteromedial surface of the petrosal) are highly variable, both intraspecifically and intraindividually. The form of the bony labyrinth of G. robustum is also described, providing the first data from this anatomical region for the family Mylodontidae. The anatomy of the bony labyrinth of the genus Glossotherium is here compared at the level of the superorder Xenarthra, including all available extant and extinct representatives, using geometric morphometric methods. In light of the new data, we discuss the evolution of inner ear anatomy in the xenarthran clade, and most particularly in sloths, considering the influence of phylogeny, allometry, and physiology on the shape of this highly informative region of the skull. These analyses show that the inner ear of Glossotherium more closely resembles that of the extant anteaters, and to a lesser extent those of the giant ground sloth Megatherium and euphractine armadillos, than those of the extant sloths Bradypus and Choloepus, further demonstrating the striking morphological convergence between the two extant sloth genera. Fil: Boscaini, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientifícas y Tecnológicas; Argentina Fil: Iurino, Dawid A.. Università degli studi di Roma "La Sapienza"; Italia Fil: Billet, Guillaume. Muséum National d'Histoire Naturelle; Francia Fil: Hautier, Lionel. Université de Montpellier; Francia Fil: Sardella, Raffaele. Università degli studi di Roma "La Sapienza"; Italia Fil: Tirao, German Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina Fil: Gaudin, Timothy. University of Tennessee; Estados Unidos Fil: Pujos, François Roger Francis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina

This study reviews and synthesises existing information generated within the SCOPSCO (Scientific Collaboration on Past Speciation Conditions in Lake Ohrid) deep drilling project. The four main aims of the project are to infer (i) the age and origin of Lake Ohrid (Former Yugoslav Republic of Macedonia/Republic of Albania), (ii) its regional seismotectonic history, (iii) volcanic activity and climate change in the central northern Mediterranean region, and (iv) the influence of major geological events on the evolution of its endemic species. The Ohrid basin formed by transtension during the Miocene, opened during the Pliocene and Pleistocene, and the lake established de novo in the still relatively narrow valley between 1.9 and 1.3 Ma. The lake history is recorded in a 584 m long sediment sequence, which was recovered within the framework of the International Continental Scientific Drilling Program (ICDP) from the central part (DEEP site) of the lake in spring 2013. To date, 54 tephra and cryptotephra horizons have been found in the upper 460 m of this sequence. Tephrochronology and tuning biogeochemical proxy data to orbital parameters revealed that the upper 247.8 m represent the last 637 kyr. The multi-proxy data set covering these 637 kyr indicates long-term variability. Some proxies show a change from generally cooler and wetter to drier and warmer glacial and interglacial periods around 300 ka. Short-term environmental change caused, for example, by tephra deposition or the climatic impact of millennial-scale Dansgaard–Oeschger and Heinrich events are superimposed on the long-term trends. Evolutionary studies on the extant fauna indicate that Lake Ohrid was not a refugial area for regional freshwater animals. This differs from the surrounding catchment, where the mountainous setting with relatively high water availability provided a refuge for temperate and montane trees during the relatively cold and dry glacial periods. Although Lake Ohrid experienced significant environmental change over the last 637 kyr, preliminary molecular data from extant microgastropod species do not indicate significant changes in diversification rate during this period. The reasons for this constant rate remain largely unknown, but a possible lack of environmentally induced extinction events in Lake Ohrid and/or the high resilience of the ecosystems may have played a role.

International audience; Sea-level rise is one of the most significant and perceptible consequences of global warming because it affects natural environments and coastal anthroposcapes at human timescales, particularly in sediment-starved littoral contexts. Within this framework, improvements in understanding the projection of sea-level rise require better knowledge of regional changes. Here we focus on the recent sea-level history of the Mediterranean Sea, an area characterized by a densely populated coast and where climate variability is larger, and the rate of sea-level rise higher than the global average. We produce a spatially-averaged Mediterranean relative sea-level (RSL) time series, based on 138 tide-gauge records, stretching back to the late 1800s, indicating that Mediterranean RSL has risen by ∼24 cm in the past ∼140 years. At interdecadal timescales and beyond, we find that Mediterranean relative sea-level rising rates (RSLRR) are significantly influenced by the strength of the Atlantic Multidecadal Oscillation (AMO) and the Atlantic Meridional Overturning Circulation (AMOC). Climate-model predictions of a weakened Atlantic overturning circulation in the coming decades, slowing and diminishing North Atlantic heat transport, has the potential to accentuate Mediterranean rising rates, with significant implications for the basin's coastal societies, infrastructure and economies. We conservatively estimate that a 0.1 °C decrease in AMO sea surface temperatures can accentuate Mediterranean RSLRR by up to −0.61 ± 0.5 mm yr−1. Future coastal management and adaptation policies must assimilate these findings into local/regional-scale impact and vulnerability assessments.

International audience; Lake Ohrid (Balkan peninsula) is the oldest European extant lake and one of the deepest and largest. Such a unique, terrestrial natural archive is especially relevant for both paleoenvironmental and paleoclimatic reconstructions but also for genetic studies. In the frame of the International Continental Scientific Drilling Program (ICDP), a deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present the summary of palynological analyses carried out in the upper 200 m of the overall 569 m long DEEP site sediment succession from the central part of the lake. These studies, performed by an international palynological team, document the main floristic, vegetation and climate changes during the last ca 500 kyr, at a millennial-scale resolution (~1.6 kyr). The continuous sediment infill permitted to trace multiple non-forested/ forested phases as a response to Glacial/Interglacial cycles as well as to sub-Milankovitch climate changes. The pollen record, corresponding with marine isotope stages MIS 13 to MIS 1, points to a progressive change from cooler and wetter to warmer and drier interglacials. New palynological studies are underway to reconstruct vegetational and climatic conditions over older intervals as well as to obtain high resolution data for some key intervals such as MIS 5-6, MIS 11-12, MIS 35-42. The complete record of changes in flora composition and vegetation during both glacials and interglacials will furnish indispensable insights for understanding the role of refugia, ecosystem resilience and maintenance of terrestrial biodiversity in the Mediterranean area.

International audience; Lake Ohrid (Balkan peninsula) is the oldest European extant lake and one of the deepest and largest. Such a unique, terrestrial natural archive is especially relevant for both paleoenvironmental and paleoclimatic reconstructions but also for genetic studies. In the frame of the International Continental Scientific Drilling Program (ICDP), a deep drilling campaign was carried out within the scope of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project in 2013. Here, we present the summary of palynological analyses carried out in the upper 200 m of the overall 569 m long DEEP site sediment succession from the central part of the lake. These studies, performed by an international palynological team, document the main floristic, vegetation and climate changes during the last ca 500 kyr, at a millennial-scale resolution (~1.6 kyr). The continuous sediment infill permitted to trace multiple non-forested/ forested phases as a response to Glacial/Interglacial cycles as well as to sub-Milankovitch climate changes. The pollen record, corresponding with marine isotope stages MIS 13 to MIS 1, points to a progressive change from cooler and wetter to warmer and drier interglacials. New palynological studies are underway to reconstruct vegetational and climatic conditions over older intervals as well as to obtain high resolution data for some key intervals such as MIS 5-6, MIS 11-12, MIS 35-42. The complete record of changes in flora composition and vegetation during both glacials and interglacials will furnish indispensable insights for understanding the role of refugia, ecosystem resilience and maintenance of terrestrial biodiversity in the Mediterranean area.

We report the results of an in-situ synchrotron X-ray powder diffraction study - performed using silicone oil as 'non-penetrating' pressure transmitting medium - of the elastic behavior of three zeolites with MFI-type framework: the natural zeolite mutinaite and two silicalites (labeled A and B) synthesized under different conditions. While in mutinaite no symmetry change is observed as a function of pressure, a phase transition from monoclinic (P2{sub 1}/n) to orthorhombic (Pnma) symmetry occurs at about 1.0 GPa in the silicalite samples. This phase transition is irreversible upon decompression. The second order bulk moduli of silicalite A and silicalite B, calculated after the fulfillment of the phase transition, are: K{sub 0}=18.2(2) and K{sub 0}=14.3 (2) GPa, respectively. These values makes silicalite the most compressible zeolite among those up to now studied in silicone oil. The structural deformations induced by HP in silicalite A were investigated by means of complete Rietveld structural refinements, before and after the phase transition, at P{sub amb} and 0.9 GPa, respectively. The elastic behaviors of the three MFI-type zeolites here investigated were compared with those of Na-ZSM-5 and H-ZSM-5, studied in similar experimental conditions: the two silicalites - which are the phases with the highest Si/Al ratiosmore » and hence the lowest extraframework contents - show the highest compressibility. On the contrary, the most rigid material is mutinaite, which has a very complex extraframework composition characterized by a high number of cations and water molecules. - Graphical abstract: High-pressure behavior of silicalite compressed in silicone oil: projection of the structure along the [0 1 0] direction at Pamb(a), 0.9 GPa (b). (c) Comparison of the unit-cell volume variations as a function of pressure for mutinaite, H-ZSM5, Na-ZSM5, silicalite A, and silicalite B compressed in silicone oil. Highlights: Black-Right-Pointing-Pointer X-ray powder diffraction study of silicalite and mutinaite compressibility. Black-Right-Pointing-Pointer Silicalite is the most compressible zeolite up to now studied. Black-Right-Pointing-Pointer A phase transition from monoclinic to orthorhombic symmetry occurs in silicalite. Black-Right-Pointing-Pointer Among MFI-type zeolites the most rigid material is mutinaite.« less

International audience; A detailed tephrostratigraphic study supported by stable isotope (δ 18 O) analyses and AMS 14 C dating was carried out on a high sedimentation rate deep-sea core recovered in the northern Ionian Sea. Eight tephra layers were recognised, all originated from explosive eruptions of southern Italian volcanoes. These tephra layers are correlated with terrestrial proximal counterparts and with both marine and lacustrine tephra already known in the central Mediterranean area. The oldest tephra (dated at ca. 19.4 ka cal BP) is tentatively correlated to the Monte Guardia eruption from Lipari Island. Two other rhyolitic tephra layers were correlated with the explosive volcanic activity of Lipari Island: Gabellotto-Fiumebianco/E-1 (8.3 ka cal BP) located close to the interruption of Sapropel S1 deposit, and Monte Pilato (ca. AD 1335) in the uppermost part of the core. The Na-phonolitic composition of the other five recognised tephra layers indicates the Somma-Vesuvius as the source. The composition is quite homogeneous among the five tephra layers, and fits that of the Mercato proximal deposits. Beyond the striking chemical similarity with the Mercato eruption, these tephra layers span over ca. 2000 years, preventing correlation with the single well known Plinian eruption of the Somma-Vesuvius. Therefore, at least two of these tephra layers were assigned to an interplinian activity of the Somma-Vesuvius between the eruptions of Mercato and Avellino, even though these eruptions remains poorly constrained in the proximal area. By contrast, the most prominent tephra layer (2 mm white tephra visible at naked eyes) was found within the S1a Sapropel interval. Despite the possible complication for the presence of similar eruption with different ages we argue that Mercato is probably a very good marker for the onset of sapropelic condition in the Ionian Sea and can be used for land-sea correlations for this important climatic event. More in general, these data allow a significant update of the knowledge of the volcanic ash dispersal from Lipari and Somma-Vesuvius volcanoes.

During the past 22 ka of activity at Somma–Vesuvius, catastrophic pyroclastic density currents (PDCs) have been generated repeatedly. Examples are those that destroyed the towns of Pompeii and Ercolano in AD 79, as well as Torre del Greco and several circum-Vesuvian villages in AD 1631. Using new field data and data available from the literature, we delineate the area impacted by PDCs at Somma–Vesuvius to improve the related hazard assessment. We mainly focus on the dispersal, thickness, and extent of the PDC deposits generated during seven plinian and sub-plinian eruptions, namely, the Pomici di Base, Greenish Pumice, Pomici di Mercato, Pomici di Avellino, Pompeii Pumice, AD 472 Pollena, and AD 1631 eruptions. We present maps of the total thickness of the PDC deposits for each eruption. Five out of seven eruptions dispersed PDCs radially, sometimes showing a preferred direction controlled by the position of the vent and the paleotopography. Only the PDCs from AD 1631 eruption were influenced by the presence of the Mt Somma caldera wall which stopped their advance in a northerly direction. Most PDC deposits are located downslope of the pronounced break-in slope that marks the base of the Somma–Vesuvius cone. PDCs from the Pomici di Avellino and Pompeii Pumice eruptions have the most dispersed deposits (extending more than 20 km from the inferred vent). These deposits are relatively thin, normally graded, and stratified. In contrast, thick, massive, lithic-rich deposits are only dispersed within 7 to 8 km of the vent. Isopach maps and the deposit features reveal that PDC dispersal was strongly controlled by the intensity of the eruption (in terms of magma discharge rate), the position of the vent area with respect to the Mt Somma caldera wall, and the pre-existing topography. Facies characteristics of the PDC deposits appear to correlate with dispersal; the stratified facies are consistently dispersed more widely than the massive facies.

Pollen records and pollen-based climate reconstructions from the Italian peninsula (central Mediterranean) show clear signals of vegetation change linked to variations in water availability in the Mediterranean basin over the past 5 million years. Profound vegetation changes occurred in four major steps from the Pliocene to the present. The subtropical taxa that dominate Pliocene assemblages declined and then disappeared between 3–2.8 and 1.66 Ma (at around 2.8 Ma in the North and later in the South), progressively being replaced by temperate Quercus forests at mid altitude. In the south Italy, Quercus expanded more at around 1.4–1.3 Ma and Fagus proportions increased after 0.5 Ma. Conifer forest (first mainly composed of Tsuga then by Abies and Picea) began to expand at 2.8 Ma, probably rather at high altitude, beginning at 2.8 Ma. Mediterranean-type forest, rare during the Early Pleistocene, developed and increased in diversity during the Middle Pleistocene. Open landscapes, with higher abundances of steppic taxa, became more frequent and extensive at the onset of Glacial/Interglacial (G/I) cyclicity around 2.6 Ma and gradually expanded with more and more marked glacials. Climate reconstructions done on selected pollen records from southern Italy suggest a decline in winter temperature and annual precipitation from the early Pleistocene to the Holocene. Specifically, both precipitation and winter temperature reconstructions show changes in interglacial maxima and glacial minima at around 3–2.8 Ma, 2 Ma, 1.3–1.4 Ma and 0.5 Ma. This critical review provides evidence that the North–South precipitation gradient, with drier conditions in the South, has been a consistent feature of the Italian peninsula since the beginning of the Pleistocene.

A synthetic high-silica mordenite (HS-MOR) has been compressed in both non-penetrating (silicone oil, s.o.) and penetrating [methanol : ethanol : water (16 : 3 : 1) (m.e.w.), water : ethanol (3 : 1) (w.e.), and ethylene glycol (e.gl.)] pressure transmitting media (PTM). In situ high-pressure (HP) synchrotron X-ray powder diffraction (XRPD) experiments allowed the unit cell parameters to be followed up to 1.6, 1.8, 8.4, and 6.7 GPa in s.o., w.e., m.e.w., and e.gl., respectively. Moreover, e.gl. was also used as a PTM in in situ HP Raman and ex situ IR experiments. The structural refinement of HS-MOR compressed in e.gl. at 0.1 GPa - the lowest investigated pressure - revealed the presence of 3.5 ethylene glycol molecules per unit cell. The infrared spectrum of the recovered sample, after compression to 1 GPa, is consistent with the insertion of ethylene glycol molecules in the pores. XRPD and Raman spectroscopy experiments performed under pressure indicated the insertion of a small number of guest molecules. Ethylene glycol is partially retained inside mordenite upon pressure release. A symmetry lowering was observed in s.o. above 0.8 GPa, while above 1.6 GPa the patterns indicated a rapid loss of long range order. From ambient pressure (Pamb) to 1.6 GPa, a high cell volume contraction (Delta V = -9.5%) was determined. The patterns collected with penetrating PTM suggested the penetration of guest molecules into the porous host matrix, starting from a very low P regime. The entrapment of PTM molecules inside micropores contributes to the stiffening of the structure and, as a consequence, to the decrease of the compressibility with respect to that measured in s.o. From the structural point of view, HS-MOR reacts to compression and to the penetration of different guest species with appropriate framework deformations. Interestingly, ethylene glycol is partially retained inside mordenite upon pressure release, which is of importance for potential application of this composite material.