We report helium isotope data for 0.03–1 Ma olivine-bearing basaltic hawaiites from three volcanoes of the southern Italy magmatic province (Ustica, Pantelleria, and Linosa Islands). Homogenous H3e/H4e ratios (range: 7.3–7.6 Ra) for the three islands, and their similarity with the ratio of modern volcanic gases on Pantelleria, indicate a common magmatic end-member. In particular, Ustica (7.6±0.2Ra) clearly differs from the nearby Aeolian Islands Arc volcanism, despite its location on the Tyrrhenian side of the plate boundary. Although limited in size, our data set complements the large existing database for helium isotope in southern Italy and adds further constraints upon the spatial extent of intraplate alkaline volcanism in southern Mediterranea. As already discussed by others, the He-Pb isotopic signature of this magmatic province indicates a derivation from a mantle diapir of a OIB-type that is partially diluted by the depleted upper mantle (MORB mantle) at its periphery.
1. Introduction
Plio-Quaternary volcanism in the Italian Peninsula has developed in the complex tectonic environment of African-European continental plate collision and Adriatic-Ionian slab subduction under the expanding Tyrrhenian Sea back-arc basin ([1] and references therein). This complexity is reflected in the wide compositional diversity of erupted magmas, which range from ultrapotassic and potassium-rich in Tuscany and the Roman-Napolitean province, to calc-alkaline in the Aeolian Island arc, and to OIB-type Na-alkaline basaltic in southern Sardinia and Sicily. This magmatic diversity is also accompanied by spectacular regional gradations in the trace-element and isotope geochemistry of volcanic products. In particular, the progressive south to north trend of 87Sr/86Sr and 18O/16O in magmas, and 13C/12C and 3He/4He in emitted gases [2–6] indicates a northward increase in contamination of magma sources by crustal material from the subducting Adriatic and Ionian plates.
Na-alkaline mafic magmatism currently active at or close to the collision plate boundary in southern Italy displays minor imprint of these subduction processes and thus provides the “cleanest” signature of the mantle beneath the region. This basaltic magmatism has developed on tensional tectonic faults cutting the African plate margin and over both a thinner crust and lithosphere (60–100 km). This basalt displays trace-element patterns typical of Ocean Island Basalts (OIB), relatively radiogenic 87Sr/86Sr and 206Pb/204Pb isotopic signatures [7–11], and has been recognized to represent a mantle component common to all Plio-Quaternary volcanic series in Mediterranea and western-central Europe [12–14]. However, the genesis of this OIB-type magmatism in a context of continental plate collision remains an enigma, for which have been proposed various, often contradictory, interpretative models (e.g., [15–17]; see [18] for a review).
The 3He/4He ratio is a well-known powerful tracer of the origin of magmas and of possible crustal contamination during magma storage and ascent (e.g., [19, 20]). 3He (essentially primordial) and 4He (produced by the radioactive decay of U and Th) have distinct origins and varying proportions in Earth’s reservoirs. Typical 3He/4He ratios vary from <0.1 Ra in continental crust (Rais the atmospheric ratio equal to 1.38×10-6), to8±1Ra on average in the upper mantle, and up to ~40–50Ra in products of plume-related ocean islands, such as Hawaii and Iceland [21, 22]. Moreover, various observations, such as He isotopic similarity in solid and gas phases at single volcanoes (e.g., [5, 23]), indicate no or minor 3He/4He fractionation during the physical processes of magma genesis, differentiation, and degassing and, therefore, can reliably be used to track magma sources.
Here, we report new results for He isotopes in olivine-bearing basaltic lavas from Ustica and Pantelleria that complement previously published data for these two islands, and 3He/4He results for Linosa, for which no data is currently available. This new data set complements a substantial existing database for helium isotopes in southern Italy and provides additional information about the spatial extent of intra-plate alkaline volcanism in southern Mediterranea.
2. Samples and Analytical Procedures
Ustica is located to the northwest of Sicily (Figure 1), and is made up of both subalkaline and alkaline basalts erupted between 750 and 130 ka [1]. Linosa and Pantelleria are located along the northwest to southeast rift system of the Sicily Channel, which separates the Sicilian platform from Africa (Figure 1). Most Linosa volcanic lithologies (1.06–0.53 Ma; [35]) are Na-alkaline to slightly transitional, mainly represented by basalts and hawaiites. The Pantelleria basalts exhibit a more complex volcanic history, which has produced mafic magmas (300–5 ka; [1]) from weakly alkaline to transitional, dominated by more evolved compositions such as trachytes, rhyolites, and pantellerites.
Location map of the study area.
We analysed 0.5 to 2 mm olivine phenocrysts contained in unaltered samples of 0.03 to ~1 Ma old pyroclastites and basaltic lava flows, some with hawaiitic composition, from the three volcanic islands [11, 36]. Sample description is given in Table 1. Olivine crystals were handpicked under a binocular microscope from the crushed whole rocks, and altered grains or those with adhering glass were carefully removed. The pure olivine separates were precleaned with distilled water and acetone in an ultrasonic bath and dried for 15 minutes at 70°C under vacuum.
Sample description (ages for Linosa, Pantelleria, and Ustica are from Lanzafame et al. [38], Civetta et al. [39], and De Vita et al. [36], resp.).
Site
LINOSA
PANTELLERIA
USTICA
Sample
Lin 15
Lin 20
Lin 27
Pant 8A
Ust 1
Ust 2
Latitude (N)
35°52′10.8′′
35°52′11.3′′
35°52′29.7′′
36°48′53.3′′
38°42′37.0′′
38°42′42.5′′
Longitude (E)
12°52′20.3′′
12°52′01.5′′
12°52′21.3′′
11°55′37.8′′
13°10′16.6′′
13°10′06.6′′
Rock type
Massive lava
Vesiculated lava
Vesiculated lava
Vesiculated lava
Coarse grain tuff
Fine grain tuff
Sampling site
Montagna Rossa
Montagna Rossa
Montagna Rossa
Cala dell’Alca
Monte Costa del Fallo
Monte Costa del Fallo
Type of outcrop
Lava flow
Lava flow
Lava flow
Lava flow
Pyroclastic flow
Pyroclastic flow
Age (Ma)
0.53–1.06
0.53–1.06
0.53–1.06
0.08–0.1
0.42–0.52
0.42–0.52
The weighed dry crystal samples (500 mg) were then loaded in a pneumatically actuated all-metal crusher. The crusher was connected to the inlet line of a MAP 215-50 noble gas mass spectrometer (CEA-Saclay facility; [37]), and pumped to ultra high vacuum overnight. After blank measurement, helium was extracted by stepwise crushing, each crushing cycle consisting of 100 strokes. Crushing cycles were renewed until the amount of extracted gas was close to the procedural blank (2.5±1.5×10-10 cm3STP 4He). In all samples, the neon content was at the blank level (<2×10-10 cc STP), thus indicating no air contamination. 3He/4He ratios were determined in reference to a routinely used air standard performed before and after each sample. The reproducibility on the air standard was better than 0.4%. Instrumental uncertainties for 3He/4He ratio and helium concentration were in the range of 0.5% to 2% and 3% to 4% respectively, depending on the amount of gas available for mass spectrometry (see Table 2).
Measured He concentrations and isotope ratios in olivine crystals from basaltic-hawaiitic lava flows from Linosa, Pantelleria and Ustica volcanic islands.
Sample
Weight (g)
Number of strokes cumulative
R/Ra
4He cumulative (10−8 cm3 STP/g)
R/Ra cumulative
Linosa
Lin 15
0.50214
100
7.27
3.58
7.27
200
7.82
3.96 ± 0.04
7.3 ± 0.2
Lin 20-1
0.51271
100
7.53
4.23
7.53
200
7.36
5.06
7.50
300
6.43
5.40
7.44
400
7.52
5.61 ± 0.04
7.4 ± 0.2
Lin 20-2
0.49958
100
7.57
4.04
7.57
200
7.55
4.91
7.56
300
7.53
5.38
7.56
400
7.54
5.62 ± 0.04
7.6 ± 0.2
Lin 27
0.50058
100
6.99
4.48
6.99
200
7.26
4.77
7.00
300
7.01
4.90 ± 0.04
7.0 ± 0.2
Pantelleria
Pant 8A
0.54177
100
7.65
0.249 ± 0.005
7.6 ± 0.3
Ustica
Ust 1
0.50126
100
7.68
11.49
7.68
200
7.56
13.00
7.67
300
7.80
13.96
7.68
400
7.21
14.61
7.66
500
8.14
15.05
7.67
600
7.97
15.40
7.68
700
8.24
15.7 ± 0.1
7.7 ± 0.2
Ust 2
0.50146
100
7.67
14.85
7.67
200
7.43
17.34
7.63
300
7.61
18.43
7.63
400
6.96
19.31
7.60
500
7.40
19.73
7.60
600
7.60
20.18
7.60
700
7.58
20.65
7.60
800
7.54
20.9 ± 0.1
7.6 ± 0.2
3. Results
The total helium concentrations in our sample set vary by two orders of magnitude (Table 2), from 2.49×10-9cm3 STP g-1 (Pantelleria) to 2.09×10-7cm3 STP g−1 (Ustica). Samples from Linosa display an intermediate, very homogenous He content averaging 4.8±0.8×10-8cm3 STP g−1. Analysis of duplicate samples Lin 20-1 and Lin 20-2 yielded identical concentration (5.6×10-8cm3 STP 4He g−1), within experimental uncertainties. The observed range in He content actually correlates with the differences in bulk crystal sizes. In particular, all olivines in Ustica samples were ≥1 mm (30% >1.4 mm), whereas 86% of olivines in Pantelleria sample were <1 mm.
Figure 2 shows that ~80% of the recovered helium was released during the first and second crushing steps, indicating that most of the entrapped helium resided in fluid inclusions or/and at grain boundaries of the olivine crystals. The fairly homogeneous 3He/4He ratio of residual helium recovered during subsequent crushing cycles (Figure 2) indicates no or minor release of either radiogenic or cosmogenic He from the crystal lattice. This is confirmed by the fact that the 0.03 Ma old Pantelleria olivines, albeit having the lowest He concentration, yielded a 3He/4He value similar to modern volcanic gases [24]. Therefore, we can safely conclude that the measured 3He/4He ratios characterize essentially pure magmatic helium trapped within the olivine crystals.
Fraction of the total helium released and 3He/4He trend as a function of the number of strokes for Linosa (squares) and Ustica (triangles) samples (N.B. due to its low He content, Pantelleria sample had only one stroke cycle).
We find that lavas from the three islands display quite homogeneous 3He/4He values, despite variable total He concentrations. Within experimental uncertainties, Pantelleria lavas (7.6±0.3Ra) have a 3He/4He ratio similar to that measured in the most pristine local volcanic gases (7.3±0.1Ra; [24]). Our results for both 3He/4He and helium abundance in olivine samples from that volcano are in reasonable agreement with those recently published by Martelli et al. [6]: 3He/4He between 6.95±0.15 and 7.12±0.3Ra, and [4He] in the range (1.9–4.2)×10−9 cm3STP/g. We find that Linosa (7.3±0.2Ra) but also Ustica (7.6±0.2Ra) display 3He/4He ratios very similar to those of Pantelleria. For Ustica, our 3He/4He values are actually higher, by as much as one Ra unit, than the values reported by Martelli et al. [6]: 6.5±0.3 to 6.65±0.2 Ra. This may reflect that their olivine samples contained about three orders of magnitude less helium (2.8–6.9×10-10 cm3STP/g) than the samples analysed in the present study (1.6–2.1×10-7 cm3STP/g).
4. Discussion
Available 3He/4He ratios for alkaline basaltic volcanoes in southern Italy are summarized in Figure 3. The helium isotope data set for Pantelleria, Linosa, and Ustica indicates a common magmatic helium component feeding the three islands with a 3He/4He distribution almost identical to that of mantle xenoliths from the Mt Iblei volcanic complex on Sicily mainland [25]. This 3He/4He range corresponds to the upper range of the 3He/4He distribution at Mount Etna (Figure 3) and is significantly higher than 3He/4He ratios of other volcanic series in Italy (Figure 4). 3He/4He values gradually decrease northward from 2.7 to 7.1Ra in the Eolian island arc [6, 40–47], 2 to 3.5Ra at Phlegrean Fields, Ischia and Mount Vesuvius [23, 48–53], down to quite radiogenic values in north-central Italy [54–58].
Histogram of helium isotopic ratio measured in volcanic gases and olivines from the islands of Pantelleria, Linosa, and Ustica ([6, 24], and this work), Mts Hyblei ([25], Etna [4–6, 26–28], and Subcontinental Lithospheric Mantle [29–32]).
3He/4He versus 206Pb/204Pb variations for Plio-Quaternary mafic magmas (MgO > 4%) in Italy compared to mantle domains and continental crust: DM stands for Depleted Mantle. The HIMU domain corresponds to the “pure” HIMU component from classical HIMU-type localities such as St. Helena and some Cook-Austral Islands. 3He/4He range for HIMU is from Hanyu and Kaneoka, (1997) [33] and Hanyu et al., 1999 [34]. All Pb isotopic data and other He data are from the review by Martelli et al, (2008) [6].
The uniform He isotopic composition of the three studied islands correlates with the broadly homogenous composition of the erupted mafic magmas in terms of their major and trace element abundances and Sr-Nd-Pb isotopic ratios [1, 8, 11], and references there in; [10, 18]). Even Ustica, which stands on the Tyrrhenian side of the African-European collision plate boundary, significantly differs in both its 3He/4He ratio and its petrological and geochemical characteristics [6, 17, 59] from calc-alkaline volcanism in the nearby Aeolian Island Arc. It is worth noticing, however, that Alicudi, the westernmost Aeolian Island, displays a 3He/4He value (6.52–7.07Ra; [6]) higher than the main Aeolian arc, which may already reflect some OIB-type influence.
Na-alkaline mafic province in southern Mediterranea (Sicily Province), with consistently higher 3He/4He ratios than any other volcanic series further north in the Italian Peninsula, is tapping a source which is the least contaminated by subduction-related metasomatism, and which may thus represent the mantle end-member of the Italian Plio-Quaternary volcanism. The possible origins of volcanic series in southern Italy have been discussed extensively in the literature with a variety of proposed interpretative models. Reviewing all these models is beyond the scope of this short note (see the recent reviews by [1, 18]), so discussion is focussed on the most salient observations. A key feature derived from seismic studies is the existence of a wide mantle upwelling zone, with low seismic velocity, beneath the whole central-western Europe, eastern Atlantic and the western Mediterranea volcanic provinces [12]. Geochemically, this low velocity component (LVC) appears as a common sublithospheric mantle end-member to Cenozoic-Quaternary volcanic series in these regions [12]. These rocks display relatively radiogenic Pb and Sr isotopic ratios (206Pb/204Pb≈19.9–20.1; 87Sr/86Sr≈0.7030–0.7034) and exhibit unradiogenic Nd isotopic ratios (143Nd/144Nd≈0.51282–0.51294), which point towards a HIMU-like OIB mantle component [54]. Many authors have emphasized this strong HIMU influence in the lavas of the Sicily Province, although this HIMU component may not have the most extreme Pb isotope composition of the classical HIMU endmember measured in OIB from south Pacific localities such as St. Helena and some Cook-Austral Islands [1, 7, 9, 15, 18, 60, 61]. Figure 4 shows the distribution of Italian volcanic series in a 3He/4He-206Pb/204Pb plot, along with the relevant mantle domains and the continental crust. Combining He with lead isotope ratios, rather than Sr-Nd isotope ratios, provides more discriminating information on possible mantle sources of basaltic volcanism, as Pb is a more incompatible element during magmatic processes and a more sensitive tracer of lithosphere recycling into the mantle. The spectacular downward trend for lavas from the Aeolian Island Arc and the Italian Peninsula in Figure 4 typically depicts the northward increasing contamination of the mantle source by Pb-rich crustal material derived from either subducted slabs or continental crust. 206Pb/204Pb ratios (and also Sr and Nd isotope ratios), for Etna lavas have isotopic characteristics that are identical to the LVC end-member even though these lavas also display some trace element ratios indicative of a subduction influence. In turn 3He/4He distributions for Etna and for the Subcontinental Lithospheric Mantle are nearly indistinguishable statistically (Figure 3), thus indicating that the isotopic similarity between Etna and LVC also apply to helium isotopes. In contrast, Pantelleria, Linosa, and Ustica volcanic islands display less radiogenic ratios and plot in intermediate position between this end-member and the Depleted Mantle (MORB mantle) domain, suggesting that additional ambient MORB asthenosphere may be entrained at the periphery of mantle upwelling.
5. Conclusions
The presented helium isotope measurements in olivines crystals from Ustica, Linosa and Pantelleria volcanic islands indicate the following.
All three islands display quite homogeneous helium isotope ratios, and 3He/4He values for olivine crystals are concordant with ratios in present-day volcanic gases of Pantelleria.
Based on all available data, the 3He/4He range delineates a quite homogeneous 250 km-wide magmatic province with a 3He/4He ratio higher than anywhere else further north in Italy.
Consistent with previous studies [4, 6, 12, 18, 25], the He-Pb isotope systematics show that this magmatic province may be fed by a mixture of HIMU-type mantle and MORB asthenosphere. These results are consistent with little or no contribution from a third 3He-richer component, in agreement with the MORB-type neon isotopic composition in Etna lavas [62] and with seismic inferences of an upwelling (“plume”) mantle source that is prevalently rooted near the transition zone at 660 km depth [12, 13].
PeccerilloA.2005Berlin, GermanySpringer-VerlagEllamR. M.HawkesworthC. J.MenziesM. A.RogersN. W.The volcanism of southern Italy: role of subduction and the relationship between potassic and sodic alkaline magmatism1989944458946012-s2.0-0024527288EllamR. M.HarmonR. S.Oxygen isotope constraints on the crustal contribution to the subduction-related magmatism of the Aeolian Islands, southern Italy1990441-21051222-s2.0-0025693695MartyB.TrullT.LussiezP.BasileI.TanguyJ. C.He, Ar, O, Sr and Nd isotope constraints on the origin and evolution of Mount Etna magmatism19941261–323392-s2.0-0028565497AllardP.Jean-BaptisteP.D'AlessandroW.ParelloF.ParisiB.FlehocC.Mantle-derived helium and carbon in groundwaters and gases of Mount Etna, Italy19971483-45015162-s2.0-0030804264MartelliM.NuccioP. M.StuartF. M.di LibertoV.BurgessR.EllamR. M.ItalianoF.Constraints on mantle source and interactions from He-Sr isotope variation in Italian Plio-Quaternary volcanism200892Q0200110.1029/2007GC001730EsperancaS.CrisciG. M.The island of Pantelleria: a case for the development of DMM-HIMU isotopic compositions in a long-lived extensional setting19951363-41671822-s2.0-0029502814TruaT.EsperançaS.MazzuoliR.The evolution of the lithospheric mantle along the N. African Plate: geochemical and isotopic evidence from the tholeiitic and alkaline volcanic rocks of the Hyblean plateau, Italy19981314307322SchianoP.ClocchiattiR.OttoliniL.SbranaA.The relationship between potassic, calc-alkaline and Na-alkaline magmatism in South Italy volcanoes: a melt inclusion approach20042201-21211372-s2.0-184253324810.1016/S0012-821X(04)00048-2RotoloS. G.CastorinaF.CelluraD.PompilioM.Petrology and geochemistry of submarine volcanism in the Sicily Channel Rift200611433553652-s2.0-3374478996110.1086/501223CivettaL.D'AntonioM.OrsiG.TiltonG. R.The geochemistry of volcanic rocks from Pantelleria Island, Sicily Channel: petrogenesis and characteristics of the mantle source region1998398145314912-s2.0-0031797179HoernleK.ZhangY. S.GrahamD.Seismic and geochemical evidence for large-scale mantle upwelling beneath the eastern Atlantic and western and central Europe1995374651734392-s2.0-0028837799GoesS.SpakmanW.BijwaardH.A lower mantle source for central European volcanism19992865446192819312-s2.0-003352113410.1126/science.286.5446.1928WilsonM.PattersonR.ErnstR. E.BuchanK. L.Intraplate magmatism related to short-wavelength convective instabilities in the upper mantle: evidence from the tertiary-quaternary volcanic province of western and central Europe2001352New York, NY, USAGeological Society of America Special Papers3758GasperiniD.Blichert-ToftJ.BoschD.del MoroA.MaceraP.AlbarèdeF.Upwelling of deep mantle material through a plate window: evidence from the geochemistry of Italian basaltic volcanics200210712236723862-s2.0-0038182607BellK.CastorinaF.RosatelliG.StoppaF.Plume activity, magmatism, and the geodynamic evolution of the Central Mediterranean200649supplement 13573712-s2.0-33749674662PeccerilloA.Quaternary magmatism in Central-Southern Italy: a new classification scheme for volcanic provinces and its geodynamic implications2002121111312735400010206291.0110LustrinoM.WilsonM.The circum-Mediterranean anorogenic Cenozoic igneous province2007811-21652-s2.0-3384713480510.1016/j.earscirev.2006.09.002LuptonJ. E.Terrestrial inert gases: isotope tracer studies and clues to primordial components in the mantle1983113714142-s2.0-0020973267HiltonD. R.HammerschmidtK.TeufelS.FriedrichsenH.Helium isotope characteristics of Andean geothermal fluids and lavas19931203-42652822-s2.0-0027843032GrahamD. W.Noble gas isotope geochemistry of mid-ocean ridge and ocean island basalts: characterization of mantle source reservoirs200247247317StuartF. M.Lass-EvansS.FittonJ. G.EllamR. M.High H3e/H4e ratios in picritic basalts from Baffin Island and the role of a mixed reservoir in mantle plumes2003424694457592-s2.0-003860289210.1038/nature01711MartelliM.NuccioP. M.StuartF. M.BurgessR.EllamR. M.ItalianoF.Helium-strontium isotope constraints on mantle evolution beneath the Roman Comagmatic Province, Italy20042243-42953082-s2.0-414306799610.1016/j.epsl.2004.05.025ParelloF.AllardP.D'AlessandroW.FedericoC.Jean-BaptisteP.CataniO.Isotope geochemistry of Pantelleria volcanic fluids, Sicily Channel rift: a mantle volatile end-member for volcanism in southern Europe20001803-43253392-s2.0-003384348710.1016/S0012-821X(00)00183-7SapienzaG.HiltonD. R.ScribanoV.Helium isotopes in peridotite mineral phases from Hyblean Plateau xenoliths (south-eastern Sicily, Italy)20052191–41151292-s2.0-1994439263710.1016/j.chemgeo.2005.02.012CarracausiA.FavaraR.GiammancoS.ItalianoF.PaonitaA.PecorainoG.RizzoA.NuccioP. M.Mount Etna: geochemical signals of magma ascent and unusually extensive plumbing system2003302142-s2.0-0038266277RizzoA.CaracausiA.FavaraR.MartelliM.PaonitaA.PaternosterM.NuccioP. M.RosciglioneA.New insights into magma dynamics during last two eruptions of Mount Etna as inferred by geochemical monitoring from 2002 to 2005200676Q0600810.1029/2005GC001175NuccioP. M.PaonitaA.RizzoA.RosciglioneA.Elemental and isotope covariation of noble gases in mineral phases from Etnean volcanics erupted during 2001–2005, and genetic relation with peripheral gas discharges20082723-46836902-s2.0-4824914750410.1016/j.epsl.2008.06.007DunaimT. J.BaurH.Helium, neon, and argon systematics of the European subcontinental mantle: implications for its geochemical evolution19955913276727832-s2.0-0029530113GautheronC.MoreiraM.Helium signature of the subcontinental lithospheric mantle20021991-239472-s2.0-003607313210.1016/S0012-821X(02)00563-0GautheronC.MoreiraM.AllègreC.He, Ne and Ar composition of the European lithospheric mantle20052171-2971122-s2.0-1534434731210.1016/j.chemgeo.2004.12.009BuikinA.TrieloffM.HoppJ.AlthausT.KorochantsevaE.SchwarzW. H.AltherrR.Noble gas isotopes suggest deep mantle plume source of late Cenozoic mafic alkaline volcanism in Europe20052301-214316210.1016/j.epsl.2004.11.001HanyuT.KaneokaI.The uniform and low H3e/H4e ratios of HIMU basalts as evidence for their origin as recycled materials199739066572732762-s2.0-003086232710.1038/36835HanyuT.KaneokaI.NagaoK.Noble gas study of HIMU and EM ocean island basalts in the Polynesian region1999637-8118112012-s2.0-003287178010.1016/S0016-7037(99)00044-7RossiG.TranneC. A.CalanchiN.LantiE.Geology, stratigraphy and volcanological evolution of the island of Linosa (Sicily Channel)199687390de VitaS.LaurenziM. A.OrsiG.VoltaggioM.Application of A40r/A39r and T230h dating methods to the chronostratigraphy of Quaternart basaltic volcanic areas: the Ustica Isand case history1998448117127Jean-BaptisteP.MantisiF.DapoignyA.StievenardM.Design and performance of a mass spectrometric facility for measuring helium isotopes in natural waters and for low-level tritium determination by the H3e ingrowth method19924378818912-s2.0-002662837710.1016/0883-2889(92)90150-DLanzafameG.RossiP. L.TranneC. A.LantiE.1994Firenze, ItalySELCACivettaL.CornetteY.CrisciP. Y.OrsiG.RequejoC. S.Geology, geochronology and chemical evolution of the island of Pantelleria198412165415622-s2.0-0021283208SanoY.WakitaH.ItalianoF.NuccioM. P.Helium isotopes and tectonics in southern Italy19891665115142-s2.0-0024485844TedescoD.Fluid geochemistry at Vulcano Island: a change in the volcanic regime or continuous fluctuations in the mixing of different systems?19951003415741672-s2.0-0028880189TedescoD.Systematic variations in the H3e/H4e ratio and carbon of fumarolic fluids from active volcanic areas in Italy: evidence for radiogenic H4e and crustal carbon addition by the subducting African plate?19971513-42552692-s2.0-0031431847TedescoD.MieleG.SanoY.ToutainJ. P.Helium isotopes ratios in Vulcano Island (southern Italy): temporal variations, shallow source mixing and deep magmatic supply1995641-211712810.1016/0377-0273(94)00045-IInguaggiatoS.RizzoA.Dissolved helium isotope ratios in ground-waters: a new technique based on gas-water re-equilibration and its application to Stromboli volcanic system20041956656732-s2.0-184284160110.1016/j.apgeochem.2003.10.009CapassoG.CarapezzaM. L.FedericoC.InguaggiatoS.RizzoA.Geochemical monitoring of the 2002-2003 eruption at Stromboli volcano (Italy): precursory changes in the carbon and helium isotopic composition of fumarole gases and thermal waters20056821181342-s2.0-3114444815410.1007/s00445-005-0427-5CapaccioniB.TassiF.VaselliO.TedescoD.PoredaR.Submarine gas burst at Panarea Island (southern Italy) on 3 November 2002: a magmatic versus hydrothermal episode200711252-s2.0-3454869901910.1029/2006JB004359B05201TedescoD.ScarsiP.Intensive gas sampling of noble gases and carbon at Vulcano Island (southern Italy)1999104510499105102-s2.0-0033542011TedescoD.Chemical and isotopic gas emissions at Campi Flegrei: evidence for an aborted period of unrest199499815623156312-s2.0-0028573362TedescoD.Chemical and isotopic investigations of fumarolic gases from Ischia island (southern Italy): evidences of magmatic and crustal contribution1996743-4233242TedescoD.AllardP.SanoY.WakitaH.PeceR.Helium-3 in subaerial and submarine fumaroles of Campi Flegrei caldera, Italy1990544110511162-s2.0-0025243184GrahamD. W.AllardP.KilburnC. R. J.SperaF. J.LuptonJ. E.Helium isotopes in some historical lavas from Mount Vesuvius1993581–43593662-s2.0-0027880924FedericoC.AiuppaA.AllardP.BellomoS.Jean-BaptisteP.ParelloF.ValenzaM.Magma-derived gas influx and water-rock interactions in the volcanic aquifer of Mt. Vesuvius, Italy200266696398110.1016/S0016-7037(01)00813-4TedescoD.ScarsiP.Chemical (He, H2, CH4, Ne, Ar, N2) and isotopic (He, Ne, Ar, C) variations at the Solfatara crater (southern Italy): mixing of different sources in relation to seismic activity199917134654802-s2.0-003276336410.1016/S0012-821X(99)00137-5HookerP. J.BertramiR.LombardiS.O'NionsR. K.OxburghE. R.Helium-3 anomalies and crust-mantle interaction in Italy19854912250525132-s2.0-0022265708MinissaleA.MagroG.VaselliO.VerrucchiC.PerticoneI.Geochemistry of water and gas discharges from the Mt. Amiata silicic complex and surrounding areas (central Italy)1997793-42232512-s2.0-0000860385MinissaleA.EvansW. C.MagroG.VaselliO.Multiple source components in gas manifestations from north-central Italy19971423-41751922-s2.0-0031408642MinissaleA.Origin, transport and discharge of CO2 in central Italy2004661-2891412-s2.0-294266807110.1016/j.earscirev.2003.09.001ItalianoF.MartinelliG.RizzoA.Geochemical evidence of seismogenic-induced anomalies in the dissolved gases of thermal waters: a case study of Umbria (Central Apennines, Italy) both during and after the 1997-1998 seismic swarm2004511Q1100110.1029/2004GC000720BarberiF.BorsiS.FerraraG.InnocentiF.Strontium isotopic composition of some recent basic volcanites of the Southern Tyrrhenian Sea and Sicily Channel19692321571722-s2.0-034443040610.1007/BF00375177D'AntonioM.TiltonG. R.CivettaL.BasuA.HartS. R.Petrogenesis of Italian alkaline lavas deduced from Pb-Sr-Nd isotope relationships199695Washington, DC, USAAmerican Geophysical Union253267PanzaG. F.PeccerilloA.AoudiaA.FarinaB.Geophysical and petrological modelling of the structure and composition of the crust and upper mantle in complex geodynamic settings: the Tyrrhenian Sea and surroundings2007801-21462-s2.0-3384528519210.1016/j.earscirev.2006.08.004NakaiS.WakitaH.NuccioM. P.ItalianoF.MORB-type neon in an enriched mantle beneath Etna, Sicily19971531-257662-s2.0-0001889028