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  • 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks  (7)
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  • 1
    facet.materialart.
    Unknown
    Geochemistry of the mantle source and magma feeding system beneath Turrialba volcano, Costa Rica (2016)
    Elsevier Science Limited
    Details
    Publication Date: 2020-10-29
    Description: Turrialba volcano lies in the southern sector of the Central American Volcanic Front (CAVF) in Costa Rica. The geochemistry of major and trace elements, and Sr and Nd isotopes of a selected suite of volcanic rocks ranging in composition from basaltic andesite to dacite and belonging to the last 10 ka of activity of Turrialba volcano is described, together with the He-, Ne-, and Ar-isotope compositions of fluid inclusions hosted in olivine and pyroxene crystals. Most of the variability in the rock chemistry is consistentwith typical trends of fractional crystallization, but there is an outlying group of andesites that displays an adakite-like composition (with a consistent depletion in high-field-strength elements and a marked enrichment in Sr) and low 3He/4He ratios (7.0–7.2 Ra). The trace-element composition of these rocks is typical of subduction-related magmas influenced by an OIB-like component at the source associated with the subduction of the Galapagos seamounts. The 87Sr/86Sr (0.703612–0.703678) and 143Nd/144Nd (0.512960–0.512984) ratios of the bulk rocks vary within narrowranges, and are among the least-radiogenic isotope signatures of the CAVF volcanoes. The 3He/4He ratios measured in fluid inclusions hosted in olivine crystals (up to 8.1 Ra) are among the highest for the CAVF, and indicate that radiogenic 4He from fluids derived fromthe subducting slab contribute negligibly to the mantle wedge. The difference in He isotopes between most of studied rocks and those showing adakite-like features reasonably reflects two distinct components in the local mantle: (1) a MORB-like component, characterized by the highest He-isotope ratios (7.8–8.1 Ra), and (2) an OIB-like component, characterized by lower He-isotope ratios (7.0–7.2 Ra), coming from the subduction of the Galapagos seamounts. An overview at the regional scale indicates that high He-isotope ratios are peculiar to the two extreme sectors of the CAVF (Costa Rica to the south and Guatemala to the north), whereas in the central sector (Nicaragua) the magma source is probably contaminated by slab fluids. For the past few years Turrialba volcano has been in a volcanic unrest phase that has included a series of explosions, the most recent of which occurred between October 2014 and May 2015. The volcano is subject to an ongoing safety alert due to the possibility of a magmatic eruption. One of the crucial questions to be addressed is the kind of eruption that can be expected, and hence what type of magma is likely to be involved. The high 3He/4He ratios (7.8–8.0 Ra) measured during 2011 at high-temperature fumaroles of Turrialba craters are comparable to those measured in fluid inclusions of basaltic andesites that erupted in 1864–1866, suggesting that the magma currently feeding the shallow plumbing system has similar geochemical characteristics to the most recently erupted magma.
    Description: Published
    Description: 319-335
    Description: 1V. Storia e struttura dei sistemi vulcanici
    Description: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Description: JCR Journal
    Description: restricted
    Keywords: Turrialba ; 3He/4He ratio ; Fluid inclusions ; Adakite ; MORB mantle ; OIB mantle ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 2
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    Coexisting calc-alkaline and ultrapotassic magmatism at Monti Ernici,Mid Latina Valley (Latium, central Italy) (2007)
    E SCHWEIZERBARTSCHE VERLAGS
    Details
    Publication Date: 2017-04-04
    Description: New major and trace element data, and Sr–Nd–Pb-O isotopic ratios for volcanic mafic rocks outcropping at Monti Ernici in the Mid Latina Valley (southern Latium) are reported, with the aim of investigating the nature and evolution of Plio- Quaternary K-rich volcanism in Central Italy. Petrographical and geochemical studies allow us to identify mafic rocks ranging from ultrapotassic (HKS) to shoshonitic (SHO), and calc-alkaline (CA), these last ones being identified for the first time. The CA rocks exhibit the most primitive signatures for Sr, Nd, and Pb isotopes (87Sr/86Sr = 0.706326-0.706654; 143Nd/144Nd = 0.512388– 0.512361; 206Pb/204Pb = 18.944-18.940). The δ18O values are variable (δ18Ocpx from +5.75 to +7.08 ‰; and δ18Ool from +5.50 to +6.23 ‰), suggesting interaction with carbonate wall rocks. Radiogenic isotope ratios and incompatible elements distribution have several characteristic in common with equivalent rocks from Pontine Islands (Ventotene), Campania and Aeolian arc volcanoes. Conversely, the HKS rocks closely resemble the ultrapotassic rocks from the Roman Province (87Sr/86Sr = 0.709679–0.711102; δ18Ocpx from +6.27 to +7.08 ‰). The high ratios of LILE (Large Ion Lithophile Elements: Rb, Cs, Th, U, K, LREE) and HFSE (High Field Strength Elements: Ta, Nb, Zr, Hf, Ti), and radiogenic isotope compositions of CA to HKS rocks indicate that all suites contain subduction-related components, and suggest a N-MORB-type mantle source variably contaminated by hydrous fluids and/or melts released by undergoing slabs, possibly during two distinct stages of metasomatism. The coexistence of ultra-alkaline and sub-alkaline orogenic magmatism, combined with tectonic, geophysical and geological evidence, support the possibility that the mantle beneath central-southern Italy (Ernici-Roccamonfina Province) was vertically zoned and produced different magma suites during time.
    Description: Published
    Description: 479-497
    Description: 3.5. Geologia e storia dei sistemi vulcanici
    Description: JCR Journal
    Description: reserved
    Keywords: Monti Ernici ; Latium magmatic Province ; calcalkaline rocks ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 3
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    A CO2-rich magma source beneath the Phlegraean Volcanic District (Southern Italy): (2012)
    Details
    Publication Date: 2017-04-04
    Description: We present a study of olivine-hosted glass/melt inclusions (MIs) in the most primitive rocks erupted at Procida Island, within the Phlegraean Volcanic District (PVD), Southern Italy. MIs were analyzed by combined Scanning Electron Microscopy coupled with Energy Dispersive X-ray-detectors, Wavelength Dispersive X-rayequipped Electron Microprobe and Fourier Transform Infrared (FT-IR) Spectroscopy; notably, the novel Focal- Plane-Array mode provided high-resolution FT-IR images evidencing the distribution of the C–H–O species across samples. Olivines range in composition from Fo85 to Fo90, do not show chemical zoning and are totally anhydrous. The majority of the MIs are glassy, while only few are completely crystallized. Some MIs, however, show the occurrence of crystal nuclei, i.e., nano- to micro-sized pyroxenes and oxides, and appear as lowcrystallized MIs. The glass of crystal-free and low-crystallized MIs shows K-affinity and a compositional range along the basalt, trachy-basalt, shoshonite, tephrite basanite and phono-tephrite array. H2O and CO2 contents up to 2.69 wt.% and 2653 ppm, respectively, define a major degassing trend with small isobaric deviations. The collected data allow recalculating entrapment pressures from ~350 MPa to b50 MPa and suggest that the magma ascent was dominated by degassing. Crystallization was aminor process, likely also consequent to local CO2-fluxing. Mingling occurred between variable degassed and crystallized magma portions during decompression. The geochemical and isotopic data of Procida glasses and rocks, and the compositional relationship between our MIs and those from slightly more evolved and radiogenic Phlegraean products, indicate that Procida basalts are an adequate parental end-member for the PVD. Our data suggest that a CO2- rich magma source was stored at depths of at least 13–14 km (i.e., 350 MPa) beneath the PVD. Fast ascent of magma batches directly started from this depth shortly before PVD trachy-basaltic to shoshonitic eruptions. Such results have implication on volcanic hazard assessment in the PVD area.
    Description: Published
    Description: 66-80
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: 3.6. Fisica del vulcanismo
    Description: 5.3. TTC - Banche dati vulcanologiche
    Description: JCR Journal
    Description: reserved
    Keywords: Melt inclusions ; Phlegraean Volcanic District ; CO2-rich magma source ; Degassing ; Fluxing ; 02. Cryosphere::02.01. Permafrost::02.01.08. Instruments and techniques ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry ; 04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 4
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    Texture and composition of pumices and scoriae from the Campi Flegrei caldera (Italy): implications on the dynamics of explosive eruptions (2008)
    AGU
    Details
    Publication Date: 2020-05-29
    Description: The Campi Flegrei (CF) caldera is one of the most dangerous quiescent volcanic systems in the world. Its activity mostly resulted in low magnitude explosive eruptions, such as that of the Monte Nuovo tuff cone that represents the last eruptive event within the caldera (AD 1538). However, there have been more energetic Plinian events, i.e., the Agnano Monte Spina eruption (4.1 ky), and very highly-explosive, caldera-forming eruptions, i.e., the Campanian Ignimbrite eruption (39 ky). Here, we integrate new and literature data on the groundmass texture and composition of pyroclastic products from the three above eruptions with the aim of unraveling how volatiles content, degassing mechanisms and crystallization processes influence magma explosivity and eruption dynamics at CF. Previous studies indicate that the investigated rocks share similar major element bulk and phenocryst chemistry; also similar is the water content of their trapped melt inclusions. These observations suggest that the magmas feeding these eruptions had comparable physico-chemical properties during storage in the shallow crust. However, our investigations indicate that the studied rocks differ in texture and composition of the groundmass and viscosity of the related magmas. We ascribe such differences to the variable style of volatile exsolution and outgassing from the melt, primarily in response to changes of the rate of magma ascent to the surface. We conclude that the magma ascent rate was the key-parameter in driving explosive eruptions at CF and we suggest that this parameter may be influenced by magma/water interaction and/or magma chamber geometry and replenishment.
    Description: Published
    Description: Q03013
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: JCR Journal
    Description: reserved
    Keywords: Campi Flegrei ; products ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 5
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    Geology, volcanic history and petrology of Vulcano (central Aeolian archipelago) (2015)
    Geological Society Publishing House
    Details
    Publication Date: 2021-12-06
    Description: Vulcano is an active NW–SE-elongated composite volcano located in the central Aeolian archipelago. Based on available radiometric ages and tephrochronology, the exposed volcanism started at c. 127 ka and spread through eight Eruptive Epochs separated by volcano-tectonic events and major quiescent stages. Various eruptive centres and two intersecting multi-stage calderas resulted from such evolution. Vulcano geological history displays several changes of eruption magnitude, eruption styles and composition of magmas through time. Vulcano rocks range from basalt to rhyolite and show variable alkali contents, roughly increasing during time. Magmas with low to intermediate SiO2 contents and high-K to shoshonite affinity prevail in the early Epochs 1–5 (c. 127–28 ka), whereas intermediate to high-SiO2 shoshonite and potassic alkaline products dominate the last three Epochs (〈30 ka). This sharp increase in silicic products is related to the shallowing of the plumbing system and resulting major role of the differentiation processes in shallow level reservoirs. Radiogenic isotope compositions are variable (87Sr/86Sr = 0.70424–0.70587, 143Nd/144Nd = 0.51254–0.51276, 206Pb/204Pb = 19.305–19.759, 207Pb/204Pb = 15.659–15.752, 208Pb/204Pb = 39.208–39.559) as a result of both source heterogeneities and shallow-level interaction of magmas with continental crust. The compositional variations of mafic magmatism with time suggest that the source zone changed from a metasomatized, fertile, ocean island basalt- (OIB-) like mantle to a metasomatized depleted lithospheric mantle.
    Description: Published
    Description: 281-349
    Description: 1V. Storia e struttura dei sistemi vulcanici
    Description: JCR Journal
    Description: restricted
    Keywords: volcanic history, stratigraphy, mapping, geochemistry, volcanic hazard ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 6
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    Unknown
    Rock magnetism and compositional investigation of Brown Tuffs deposits at Lipari and Vulcano (Aeolian Islands — Italy) (2012)
    Elsevier
    Details
    Publication Date: 2021-12-06
    Description: A rock-magnetic investigation was carried out on the nonwelded ash deposits of the Brown Tuffs (Aeolian Islands, southern Tyrrhenian Sea) to improve the stratigraphic correlation between the deposits cropping out on Lipari and Vulcano islands and locate their source area. The study was supplemented by petrographical and geochemical analyses on selected strata, with the intent to compare the Brown Tuffs to other rocks emplaced at Vulcano in the same time span. More than 30 levels were sampled in the intermediate (56± 4 kaNIBTN21–22 ka) and upper (21–22 kaNUBT) parts of the Brown Tuffs sequences on the two islands. Their characteristic remanent magnetization (ChRM) directions were derived from stepwise thermal demagnetization, and the magnetic fabric from measurements of the anisotropy of magnetic susceptibility. The levels with indistinguishable ChRM directions were regarded as coeval and to form an individual stratigraphic unit. The units were referred to the Brown Tuffs sequence of Lucchi et al. (2008) on the grounds of their emplacement age, provided by comparison of their mean paleomagnetic direction with the paleosecular variation curves of the southern Tyrrhenian region, as well as the field constraints. The closer correlation between the sequences of Lipari and Vulcano contributes to a better understanding of the volcanic activity that produced the Brown Tuffs, and shows that most of the IBT and the oldest UBT levels were emplaced in a short time span, between ≈24 and 20–17 ka. The magnetic fabric is typically well developed, but at most sites the magnetic foliation is very close to horizontal and no imbrication is defined. The source area of the Brown Tuffs parent pyroclastic flows, as constrained from the intersection of the magnetic lineations, falls in the northeastern part of La Fossa Caldera structure. Although limited to major elements, compositional data provide further indication about the parent plumbing system and its behaviour. Magma batch(es) involved in the IBT eruptions have homogeneous features and underwent frequent refilling and tapping processes. Conversely, those involved in the early UBT eruptions are compositionally more variable. This suggests more complex evolution and plumbing system activity: the UBT eruptions represent either residual mafic magmas from the previous eruptions or the arrival of new, fresh shoshonitic magma in the system.
    Description: Published
    Description: 23-38
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: JCR Journal
    Description: reserved
    Keywords: Brown Tuffs ; Magnetic fabric ; pyroclastic rocks ; Aeolian Islands ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 7
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    Unknown
    Volcanic and tectonic history of El Tatio area (central Andes, northern Chile): explanatory notes to the 1:50000 scale geological map (2011)
    Dipartimento di Scienze della Terra e Geologico-Ambientali of the University of Bologna (Italy), in collaboration with GeoSed, the Italian Association for Sedimentary Geology
    Details
    Publication Date: 2021-12-06
    Description: The volume has the geological map as attached paper
    Description: The Miocene-Quaternary eruptive and tectonic history of El Tatio volcanic area (central Andes, northern Chile) is described here on the basis of a new 1:50,000 scale geological map.
    Description: Published
    Description: 1-29
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: N/A or not JCR
    Description: reserved
    Keywords: El tatio geothermal field ; stratovolcano ; ignimbrite ; thrust faults ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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