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South-Eastern Spain is a key locality of the Western Mediterranean to unravel the origin of post-collisional magmatism and its relationships with the multi-stage evolution of the upper mantle in complex geodynamic settings. This study is focused on the Plio-Pleistocene post-collisional intraplate-like alkali basalts cropping out in the Tallante area (South-Eastern Spain) that are erupted in a region previously characterised by subduction related calc-alkaline to ultrapotassic (i.e., lamproitic) volcanism. Tallante alkali basalts represent a volcanic episode similar to other contemporary small volume intraplate volcanic occurrences of Western-Central Europe and North Africa, which are believed to derive from a Common Mantle Reservoir characterising the entire Circum Mediterranean asthenosphere. We report new major, trace element, and Sr-Nd-Pb isotope data on Tallante alkali basalts, showing compositions broadly similar to the other mafic volcanic rocks derived from the Common Mantle Reservoir and thus suggesting an asthenospheric component similar to other European within plate volcanic rocks. On the other hand, specific trace element ratios, such as Ce/Pb, Nb/U, Th/Yb, along with delta207Pb/204Pb and 87Sr/86Sr, clearly indicate the involvement of an enriched, subduction-related component, with a lamproitic geochemical and isotopic flavour. The trace element ratios suggest that low melting degree magmas from the Common Mantle Reservoir infiltrated and triggered melting of the strongly metasomatised sub-continental lithospheric mantle, which produced the lamproitic magmas previously erupted in the same area. The proposed origin of Tallante alkali basalts, located along a large scale left-lateral strike-slip fault, is consistent with analytical, numerical and laboratory models indicating that narrow subduction zones such as the Gibraltar Arc are characterised by mantle inflow around the slab edges determining upwelling and adiabatic melting of the asthenospheric mantle through slab tears.

Etna volcano in Italy releases an exceptional amount of CO2 (9083 t/day) and contributes to 10% of global volcanic emission. The reasons for its extreme CO2 degassing are not yet understood. Using high-precision high field strength element (HFSE) concentrations in magmas from volcanoes in southern Italy, we show that the high Nb/Ta of Etna (up to 26) reveals a mantle source affected by carbonatite metasomatism, which is likely responsible for the large CO2 fluxes. As observed at Etna, carbon-rich mantle domains influence CO2 degassing also outside of continental rifts and therefore play a fundamental role in explaining volcanic CO2 fluxes in different geodynamic settings. Collectively, our study demonstrates that HFSE ratios in magmatic rocks are viable tracers for volcanic carbon degassing that can be used to study present-day settings and, possibly, past emissions.

High-MgO lamproite and lamproite-like (i.e. lamprophyric) ultrapotassic rocks are recurrent in the Mediterranean and surrounding regions. They are associated in space and time with ultrapotassic shoshonites and high-K calc-alkaline rocks. This magmatism is linked with the geodynamic evolution of the westernmost sector of the Alpine-Himalayan collisional margin, which followed the closure of the Tethys Ocean. Subduction-related lamproites, lamprophyres, shoshonites and high-K calc-alkaline suites were emplaced in the Mediterranean region in the form of shallow level intrusions (e.g. plugs, dykes and laccoliths) and small volume lava flows, with very subordinate pyroclastic rocks, starting from the Oligocene, in the Western Alps (northern Italy), through the Late Miocene in Corsica (southern France) and in Murcia-Almeria (southeastern Spain), to the Plio-Pleistocene in Southern Tuscany and Northern Latium (central Italy), in the Balkan peninsula (Serbia and Macedonia) and in the Western Anatolia (Turkey). The ultrapotassic rocks are mostly lamprophyric, but olivine latitic lavas with a clear lamproitic affinity are also found, as well as dacitic to trachytic differentiated products. Lamproite-like rocks range from slightly silica under-saturated to silica over-saturated composition, have relatively low Al2O3, CaO and Na2O contents, resulting in plagioclase-free parageneses, and consist of abundant K-feldspar, phlogopite, diopsidic clinopyroxene and highly forsteritic olivine. Leucite is generally absent, and it is rarely found only in the groundmasses of Spanish lamproites. Mediterranean lamproites and associated rocks share an extreme enrichment in many incompatible trace elements and depletion in High Field Strength Elements and high, and positively correlated Th/La and Sm/La ratios. They have radiogenic Sr and unradiogenic Nd isotope compositions, high 207Pb over 206Pb and high time-integrated 232Th/238U. Their composition requires an originally depleted lithospheric mantle source metasomatized by at least two different agents: (1) a high Th/La and Sm/La (i.e. SALATHO) component deriving from lawsonite-bearing, ancient crustal domains likely hosted in mélanges formed during the diachronous collision of the northward drifting continental slivers from Gondwana; (2) a K-rich component derived from a recent subduction and recycling of siliciclastic sediments. These metasomatic melts produced a lithospheric mantle source characterized by network of felsic and phlogopite-rich veins, respectively. Geothermal readjustment during post-collisional events induced progressive melting of the different types of veins and the surrounding peridotite generating the entire compositional spectrum of the observed magmas. In this complex scenario, orogenic Mediterranean lamproites represent rocks that characterize areas that were affected by multiple Wilson cycles, as observed in the Alpine-Himalayan Realm.

Magmas in volcanic arcs have geochemical and isotopic signatures that can be related to mantle metasomatism due to fluids and melts released by the down-going oceanic crust and overlying sediments, which modify the chemistry and mineralogy of the mantle wedge. However, the effectiveness of subduction-related metasomatic processes is difficult to evaluate because the composition of arc magmas is often overprinted by interactions with crustal lithologies occurring during magma ascent and emplacement. Here, we show unequivocal evidence for recycling of continental crust components into the mantle. Veined peridotite xenoliths sampled from Tallante monogenetic volcanoes in the Betic Cordillera (southern Spain) provide insights for mantle domains that reacted with Si-rich melts derived by partial melting of subducted crustal material. Felsic veins crosscutting peridotite and the surrounding orthopyroxene-rich metasomatic aureoles show the highest 18O/16O ratios measured to date in upper mantle assemblages worldwide. The anomalously high oxygen isotope compositions, coupled with very high 87Sr/86Sr values, imply the continental crust origin of the injected melts. Isotopic anomalies are progressively attenuated in peridotite away from the veins, showing 18O isotope variations well correlated with the amount of newly formed orthopyroxene. Diffusion may also affect the isotope ratios of mantle rocks undergoing crustal metasomatism due to the relaxation of 18O isotope anomalies to normal mantle values through time. Overall, the data define an O isotope “benchmark” allowing discrimination between mantle sources that attained re-equilibration after metasomatism (>5 Myr) and those affected by more recent subduction-derived enrichment processes.

The northern and northwestern margins of the Arabian Plate are a locus of a diffuse and long-lasting (early Miocene to Pleistocene) Na-alkali basaltic volcanism, sourced in the asthenosphere mantle. The upwelling asthenosphere at the Africa–Arabia margin produces very limited magma volumes in the axial zone. Therefore, portions of hot, fertile mantle continue their eastward migration and are stored at shallower depths under the 100-km thick Arabian lithosphere, which is much thinner than the African one (≈175 km): this causes the occurrence and 20-Ma persistence of magma supply under the study area. Erupted basalts sampled a continuous variation of the mantle source, with a striking correlation among temperature, pressure and isotopic composition shifting between two end members: a 100 km-deep, more depleted source, and a 60 km-deep, more enriched one. In particular, we observed an unusual variation in boron isotopes, which in the oceanic domain does not vary between more depleted and more enriched mantle sources. This study shows that, at least in the considered region, subcontinental mantle is more heterogeneous than the suboceanic one, and able to record for very long times recycling of shallow material.

In this paper we report an experimental study to assess the process of Sr-isotope uptake from the soil and its transfer to the grapevine and then to the wine made through micro-vinification. The experimental work has been carried out with a deep control of the boundary conditions (i.e., type of soil, geologic substratum, ground water supply, etc.) on 11 selected vine-plant sites over a period of four harvest years. Sr-isotopes have been determined on grape-bunches, grapevine sap, on the bioavailable fraction of the soil, on bulk soil, and on the rocks of the substratum. No significant Sr-isotope variability has been observed among micro-vinifications from different harvest years. A slight but significant Sr-isotope variability occurred among wines from rows embedded on different soil type. The Sr-isotope data on micro-vinifications well match those of grapevine sap and bioavailable fraction of soils, all of them falling well within the whole geological range of the bedrock, despite an evident decoupling between bioavailable fraction, whole soils and bedrocks does exist. This decoupling has been ascribed to differential geochemical behaviour of minerals in response to pedogenetic processes. The findings of our experiments indicate that the biological activity of the vine is not able to change the original 87Sr/86Sr composition up-taken from the bio-available fraction of the soil. Thus, the 87Sr/86Sr of the wine is an unadulterated feature of the terroir.

An analytical protocol for high-precision, in situ microscale isotopic investigations is presented here, which combines the use of a high-performing mechanical microsampling device and high-precision TIMS measurements on micro-Sr samples, allowing for excellent results both in accuracy and precision. The present paper is a detailed methodological description of the whole analytical procedure from sampling to elemental purification and Sr-isotope measurements. The method offers the potential to attain isotope data at the microscale on a wide range of solid materials with the use of minimally invasive sampling. In addition, we present three significant case studies for geological and life sciences, as examples of the various applications of microscale 87Sr/86Sr isotope ratios, concerning (i) the pre-eruptive mechanisms triggering recent eruptions at Nisyros volcano (Greece), (ii) the dynamics involved with the initial magma ascent during Eyjafjallajökull volcano’s (Iceland) 2010 eruption, which are usually related to the precursory signals of the eruption, and (iii) the environmental context of a MIS 3 cave bear, Ursus spelaeus. The studied cases show the robustness of the methods, which can be also be applied in other areas, such as cultural heritage, archaeology, petrology, and forensic sciences.

Ultramafic xenoliths are rarely found at convergent plate margins. A notable exception is in the Betic Cordillera of southern Spain, where the eruption of xenolith-bearing alkaline basalts during the Pliocene post-dated the Cenozoic phase of plate convergence and subduction-related magmatism. Mantle xenoliths of the monogenetic volcano of Tallante display extreme compositional heterogeneities, plausibly related to multiple tectono-magmatic episodes that affected the area. This study focuses on two peculiar composite mantle xenolith samples from Tallante, where mantle peridotite is crosscut by felsic veins of different size and mineralogy, including quartz, orthopyroxene, and plagioclase. The veins are separated from the peridotite matrix by an orthopyroxene-rich reaction zone, indicating that the causative agents were alkali-rich hydrous silica-oversaturated melts, which were likely related to recycling of subducted continental crust components. The present study reports new and detailed major and trace elements and Sr-Nd-Pb analyses of the minerals in the composite Tallante xenoliths that confirm the continental crust derivation of the metasomatic melts, and clarifies the mode in which subduction-related components are transferred to the mantle wedge in orogenic areas. The particular REE patterns of the studied minerals, as well as the variation of the isotopic ratios between the different zones of the composite xenoliths, reveal a complex metasomatic process. The distribution of the different elements, and their isotope ratios, in the studied xenoliths are controlled by the mineral phases stabilised by the interaction between the percolating melts and the peridotitic country rock. The persistence of marked isotopic heterogeneities and the lack of re-equilibration suggest that metasomatism of the sub-continental lithospheric mantle occurred shortly before the xenolith exhumation. In this scenario, the studied xenoliths and the metasomatic processes that affected them may be representative of the mantle sources of mafic potassic to ultrapotassic magmas occurring in post-collisional tectonic settings.

The Mediterranean area is one of the most intriguing places on Earth where geodynamics and volcanoes are strictly related, and evolved through time. The complexity of the tectonic setting is further enriched by the observed shift of the petrochemical affinity of magmas, in the same volcanic area, from subduction-related to intraplate. The successive opening of back-arc basins (e.g., Ligurian-Provençal basin, Tyrrhenian Sea), following the roll-back of the subducting Adria Plate, produced a migration of magmatism to form a transitional eastward pattern of volcanoes both onshore and offshore. The Mio-Pliocene volcanic rocks occurring in the Central Mediterranean area are characterised by exceptional variability of the petro-chemical and isotopic features, which allow the distinction of several sectors, when also the areal distribution is considered. Thus, the Mediterranean area has always been site of studies focused on magma genesis and on the geodynamic significance of the complex scenario achieved through time. In the scientific literature, a large number of papers were published on the magmatism of each single volcanic association/area, but very few dealt with the general picture of the offshore magmatic and geodynamic evolution. The aim of this chapter is to provide an outline of the most prominent geological, petrological, geochemical and isotopic characteristics of the submarine volcanic centres found in the Central Mediterranean basin, with the aim of providing a fairly complete picture of the existing relationships between the geodynamics and the igneous petrology in this area.

Tertiary volcanic rocks in northwestern Firoozeh, Iran (the Meshkan triangular structural unit), constitute vast outcrops (up to 250 km2) of high-Mg basaltic andesites to dacites that are associated with high-Nb hawaiites and mugearites. Whole-rock 40Ar/39Ar ages show a restricted range of 24.1 ± 0.4-22.9 ± 0.5 Ma for the volcanic rocks. The initial ratios of 87Sr/86Sr and 143Nd/144Nd vary from 0.703800 to 0.704256 and 0.512681 to 0.512877, respectively, in the high-Mg basaltic andesites-dacites. High-Th contents (up to 11 ppm) and Sr/Y values (27-100) and the isotopic composition of the subalkaline high-Mg basaltic andesites-dacites indicate derivation from a mantle modified by slab and sediment partial melts. Evidence such as reverse zoning and resorbed textures and high Ni and Cr contents in the evolved samples indicate that magma mixing with mafic melts and concurrent fractional crystallization lead to the compositional evolution of this series. The high-Nb hawaiites and mugearites, by contrast, have a sodic alkaline affinity and are silica undersaturated; they are also enriched in Nb (up to 47 ppm) and a wide range of incompatible trace elements, including LILE, LREE, and HFSE. Geochemistry and Sr- Nd isotopic compositions of the high-Nb hawaiites and mugearites suggest derivation from a mantle source affected by lower degrees of slab melts. Post-orogenic slab break-off is suggested to have prompted the asthenospheric upwelling that triggered partial melting in mantle metasomatized by slab-derived melts.

Intense Cenozoic magmatism accompanied the convergence and collision of the Eurasian, African and Arabian plates. In the Cappadocia Region of Central Anatolia, widespread and abundant volcanism developed from the late Miocene to the Quaternary. Calc-alkaline pyroclastic products and lava erupted diffusely during the late Miocene and Pliocene. Both calc-alkaline and Na-alkaline volcanic rocks were emplaced in close spatial and temporal proximity during the Plio-Pleistocene. Here we focus on the Plio-Pleistocene monogenetic activity, which produced two types of rocks: calc-alkaline volcanic rocks ranging in composition from basalts to rhyolites and occurring around the Acigol caldera, the Gollu Dag dome and the Hasan Dag and Erciyes Dag composite volcanoes; Na-alkaline volcanic rocks ranging from alkali basalts to mugearites and cropping out in monogenetic centres in Karapinar, along the WSW flank of Hasan Dag, in Acigol and near the Kizilirmak River, northwest of Nevsehir. The coeval occurrence of calc-alkaline and Na-alkaline volcanism observed here is in striking contrast with activity in the surrounding Western and Eastern Anatolia regions, where the calc-alkaline volcanic rocks are distinctly older than the Na-alkaline ones. The Sr and Nd isotopic compositions of the mantle sources of both rock types show a narrow, overlapping range of values (87Sr/86Sr~0.70395–0.70474 and 143Nd/144Nd~0.51268–0.51281 for the calc-alkaline products, 0.70334–0.70524 and 0.51268–0.51293 for the Na-alkaline ones). In addition, most of the Na-alkaline products, like the calc-alkaline rocks, show an arc-type distribution of incompatible trace elements, with marked enrichments in LILE (Large-Ion Lithophile Elements) and negative HFSE (High Field Strength Elements) anomalies. True intraplate magmas are absent in Cappadocia, where the genesis of Na-alkaline basalts is ascribed to mixing between different percentages of within-plate (OIB) and calc-alkaline magmas. Modelling reveals that the addition of 13% and 30% OIB-type melt to a calc-alkaline magma is enough to change a SiO2-oversaturated magma into an ol-hy-normative and ne-normative one, respectively, whereas the addition of 15% calc-alkaline magma to an OIB-type magma results in a negative Nb Ta anomaly in the primitive mantle-normalized spider diagrams. The various types of products of recent volcanism in Cappadocia reflect the complex tectonic setting of the Central Anatolian Block: characterised by strike-slip tectonics and local extensional pull-apart basins, different magma types formed contemporaneously through decompression melting at different depths. In this scenario, the calc-alkaline magmas derived from partial melting of a mantle wedge modified by a subduction component, whereas the within-plate (OIB) magmas derived from a deeper, unmodified sub-slab mantle source. Mixing between calc-alkaline and within-plate magmas during their rise to the surface produced the Na-alkaline Cappadocia basalts. The very low rate of extension allowed within-plate magmas (OIB) to reach the surface after having interacted with the overlying calc-alkaline magmas in the late stages of Cappadocia volcanism.

The active volcano of Ischia, the well-known island off-shore the city of Naples, has had a discontinuous volcanic activity characterised by caldera-forming paroxysmal eruptions, lava flows, and lava domes for >150 kyr. The overall geochemical composition of erupted magmas includes shoshonite, latite, and trachyte/trachyphonolite. In a complementary study, we demonstrated that the evolution of Ischia trachytes with Sr 10 wt.% outcrop a few kilometers apart at Procida island, and suggest that the evolved latites and trachytes at Ischia might have originated by crustal assimilation processes affecting Procida basalts. However, Energy Constrained Assimilation and Fractional Crystallisation modelling sets robust constraints against this hypothesis and provide geochemical arguments for a pristine mantle-derived radiogenic isotope signature for trachytes and latites, implying that they also evolved from parental basaltic magmas in a closed-system environment akin to trachytes with Sr

The fate of carbonate-rich sediments recycled at destructive plate margins is a key issue for constraining the budget of deep CO2 supplied to the atmosphere by volcanism. Experimental studies have demonstrated that metasomatic melts can be generated by partial melting of subducted carbonate-pelitic sediments, but signatures of the involvement of such components in erupted magmas are more elusive. We have made new U-Th disequilibria, Sr-Nd-Pb isotope, and high-precision delta238U analyses on lavas from Mount Vesuvius (Italy) and show that their measured 238U excesses require a mantle source affected by the addition of U-rich carbonated melts, generated by partial melting of subducted calcareous sediments in the presence of residual epidote. Accordingly, we argue that the occurrence of 238U excesses in "sediment-dominated" arc magmas represents diagnostic evidence of addition of carbonate sediments via subduction, hence providing constraints on deep carbon cycling within Earth. Our quantitative enrichment model, combined with published experimental results, allows us to estimate a resulting flux of 0.15-0.8 Mt/yr CO2 from the subducted carbonates to the mantle source of Mount Vesuvius.

Le collane editoriali del servizio Geologico d’italia nascono contemporaneamente con l’istituzione del R. Comitato Geologico. una delibera del giugno 1869 sancisce che la pubblicazione della Carta geologica deve essere affiancata dalla stampa del Bollettino e delle Memorie per diffondere alla comunità scientifica quanto prodotto in italia, oltre a favorire lo scambio di riviste e monografie con gli altri servizi geologici. il primo numero del “Bollettino del R. Comitato Geologico” venne pubblicato nel 1870, continuando le sue pubblicazioni con il titolo di “Bollettino del R. ufficioGeologico d’italia”. La pubblicazione delle “Memorie per servire alla descrizione della Carta geologica d’italia” prende avvio nel 1871, con il primo volume curato da igino Cocchi. La serie delle “Memorie descrittive della Carta geologica d’italia” invece, comincia a essere pubblicata nel 1886 e prosegue, seppure con discontinuità, fino ad oggi. nel febbraio 2009 il “Bollettino del servizio geologico d’italia” e quello della “società geologica italiana”, fondato nel 1882, danno vita ad una nuova rivista scientifica internazionale: l’Italian Journal of Geosciences. nello stesso anno, sempre in collaborazione con la società geologica italiana, è stata attivata una nuova rivista semestrale online, i Geological Field Trips, che pubblica itinerari geologici presentati in occasione di convegni e congressi nazionali e internazionali.