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    Publication Date: 2017-04-04
    Description: During its 1800-year-long persistent activity the Stromboli volcano has erupted a highly porphyritic (HP) volatile-poor scoriaceous magma and a low porphyritic (LP) volatile-rich pumiceous magma. The HP magma is erupted during normal Strombolian explosions and lava effusions, while the LP one is related to more energetic paroxysms. During the March–April 2003 explosive activity, Stromboli ejected two typologies of juvenile glassy ashes, namely highly vesicular LP shards and volatile-poor HP shards. Their textural and in situ chemical characteristics are used to unravel mutual relationships between HP and LP magmas, as well as magma dynamics within the shallow plumbing system. The mantle-normalized trace element patterns of both ash types show the typical arc-lava pattern; however, HP glasses possess incompatible element concentrations higher than LP glasses, along with Sr and Eu negative anomalies. HP shards are generally characterized by higher Li contents (to ~20 ppm) and lower δ7Li values (+1.2 to −3.8‰) with respect to LP shards (Li contents of 7–14 ppm and δ7Li ranging between +4.6 and +0.9‰). Fractional crystallization models based on major and trace element compositions, combined with a degassing model based on open-system Rayleigh distillation and on the assumption that melt/fluidDLi 〉 1, show that abundant (~30%) plagioclase precipitation and variable degrees of degassing can lead the more primitive LP magma to evolve toward a differentiated (isotopically lighter) HP magma ponding in the upper conduit and undergoing slow continuous degassing-induced crystallization. This study also evidences that in March 2003 Stromboli volcano poured out a small early volume of LP magma that traveled slower within the conduit with respect to later and larger volumes of fast ascending LP magma erupted during the April 5 paroxysm. The different ascent rates and cooling rates of the two LP magma batches (i.e., pre- and post-paroxysm) resulted in small, but detectable, differences in their chemical signatures. Finally, this study highlights the high potential of in situ investigations of juvenile glassy ashes in petrologic and geochemical monitoring the volcanic activity and of Li isotopes as tracers of degassing processes within the shallow plumbing system.
    Description: In press
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: JCR Journal
    Description: reserved
    Keywords: Stromboli ; Volcanic ash ; Lithium isotopes ; Degassing ; induced crystallization ; Petrologic monitoring ; 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::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 4
    Publication Date: 2017-04-04
    Description: We present a geochemical study on olivine- and clinopyroxene-hosted melt inclusions (MIs) from 2001-2006 Etna basaltic lavas and pyroclastites. Three MI suites are distinguished on the basis of trace element fingerprinting. Type-1 MIs (from 2001 Upper South and 2002 Northeast vents) share their trace element signature with low-K lavas erupted before 1971. Critical trace element ratios (e.g.,K/La, Ba/Nb), along with Pb isotope data of Type-1 MIs provide evidence for a heterogeneous mantle source resulting from mixing of three end-members with geochemical and isotopic characteristics of EM2, DMM and HIMU components. Type-1 MIs composition does not support involvement of subduction-related components. Type-2 (from 2001 Lower and 2002 South vents) and Type-3 (2004 eruption) MIs reveal “ghost plagioclase signatures”, namely lower concentrations in strongly incompatible elements, and positiveSr, Ba and Eu anomalies. Both Type-1 and Type-2 MIs occur in 2006 olivines, which highlight the occurrence of mixing between Type-1 and Type-2 end-members. Type-2/Type-3 MIs testify to en-route processes(plagioclase assimilation and volatile fluxing) peculiar for “deep dike fed” eruptions. The latter are strongly controlled by tectonics or flank instability that occasionally promote upraise ofundegassed, more radiogenic primitive magma, which may interact with plagioclase-rich crystal mush/cumulates before erupting. Type-2/Type-3 MIs approach the less radiogenic Pb isotopic compositionof plagioclase from prehistoric lavas, thus suggesting geochemical overprinting of present-day melts by older products released from distinct mantle sources. Our study emphasizes that MIs microanalysis offers new insights on both source characteristics and en-route processes, allowing to a link between melt composition and magma dynamics.
    Description: Published
    Description: 2109–2126
    Description: 1V. Storia e struttura dei sistemi vulcanici
    Description: JCR Journal
    Description: restricted
    Keywords: Mt. Etna ; source heterogeneity ; melt inclusion ; ghost plagioclase ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 5
    Publication Date: 2017-04-04
    Description: During its 1800-year-long persistent activity the Stromboli volcano has erupted a highly porphyritic (HP) volatile-poor scoriaceous magma and a low porphyritic (LP) volatile-rich pumiceous magma. The HP magma is erupted during normal Strombolian explosions and lava effusions, while the LP one is related to more energetic paroxysms. During the March–April 2003 explosive activity, Stromboli ejected two typologies of juvenile glassy ashes, namely highly vesicular LP shards and volatile-poor HP shards. Their textural and in situ chemical characteristics are used to unravel mutual relationships between HP and LP magmas, as well as magma dynamics within the shallow plumbing system. The mantle-normalized trace element patterns of both ash types show the typical arc-lava pattern; however, HP glasses possess incompatible element concentrations higher than LP glasses, along with Sr and Eu negative anomalies. HP shards are generally characterized by higher Li contents (to ~20 ppm) and lower δ7Li values (+1.2 to −3.8‰) with respect to LP shards (Li contents of 7–14 ppm and δ7Li ranging between +4.6 and +0.9‰). Fractional crystallization models based on major and trace element compositions, combined with a degassing model based on open-system Rayleigh distillation and on the assumption that melt/fluidDLi 〉 1, show that abundant (~30%) plagioclase precipitation and variable degrees of degassing can lead the more primitive LP magma to evolve toward a differentiated (isotopically lighter) HP magma ponding in the upper conduit and undergoing slow continuous degassing-induced crystallization. This study also evidences that in March 2003 Stromboli volcano poured out a small early volume of LP magma that traveled slower within the conduit with respect to later and larger volumes of fast ascending LP magma erupted during the April 5 paroxysm. The different ascent rates and cooling rates of the two LP magma batches (i.e., pre- and post-paroxysm) resulted in small, but detectable, differences in their chemical signatures. Finally, this study highlights the high potential of in situ investigations of juvenile glassy ashes in petrologic and geochemical monitoring the volcanic activity and of Li isotopes as tracers of degassing processes within the shallow plumbing system.
    Description: Published
    Description: 541-561
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: JCR Journal
    Description: reserved
    Keywords: Stromboli ; Volcanic ash ; Lithium isotopes ; Degassing-induced crystallization ; Petrologic monitoring ; 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::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 6
    Publication Date: 2021-05-19
    Description: Un desove inducido por tratamiento hormonal al pargo criollo Lutjanus analis fue desarrollado en el Centro de Desove de Peces Marinos en Santa Cruz del Sur, Camagüey. Se empleó la hormona gonodatropina coriónica humana (dosis de 500 y 1 000 UI/kg) en machos y hembras respectivamente, con peso promedio de 4,05 ± 0,33 kg. Entre las 40 y 42 h postinducción, 440 000 huevos con diámetro promedio de 876,9 ± 181,8 μm fueron colectados y depositados en tanques cilíndrico-cónicos de 200 L. Se registraron valores de temperatura, salinidad, oxígeno e intensidad luminosa, además de observaciones microscópicas cada 2 h, con el objetivo de identificar los cambios ocurridos en los diferentes estadios. El porcentaje de fertilización fue de 34,77 % en huevos esféricos, pelágicos y transparentes con una sola gota de lípidos. Dos horas después del desove (hdd) fue observado el período de blástula, y la gástrula 50 min después. Los embriones fueron observados en forma de C y S a las 5:12 y 5:47 hdd respectivamente. Se obtuvieron embriones pigmentados antes de las 14 hdd, encontrándose la mayor concentración de melanóforos en la porción ventral de la zona preanal y hasta su porción caudal. Los huevos eclosionados (16-19 hdd) produjeron larvas con saco vitelino de forma alongada hasta la parte anterior de la cabeza, absorbido aproximadamente a las 30 h después del desove. El desarrollo larval fue constante y las larvas eclosionadas llegaron a una longitud máxima de 3,9 mm.
    Description: Principal aspects from larval and embryonic development of induced spawning mutton snapper (Lutjanus analis) were achieved. The eggs and larvae were cultured in black fibreglass tanks using the green water technique. The spawning occurred 40-42 h after the injection with 440 000 eggs (Ø = 876,9 ± 181,8 μm) which reached the early gastrula stage 4:35 h after fertilization. Temperature, salinity and oxygen were determined. In addition, microscopic observations used to be for proving information related to this specie. The eggs were transparent, spherical, and pelagic. The pigmented embryos were obtained before 14 h post-spawn (pts) when dorsal melanophores over the somites were first evident. Day-1 larvae were characterized by an elongate yolk sac in which the oil globule was situated at the extreme anterior end. Absorption of yolk sac was complete at 30 h pts. Overall size of larvae changed very little approaching 3,9 mm standard length. Transformation of larvae to juveniles did not occur during the period of development observed.
    Description: Published
    Keywords: Saco vitelino ; Lutjanus analis ; Desarrollo embrionario y larval ; Yolk sac ; Embryonic and larval development
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed
    Format: pp.49-52
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  • 7
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 87 (1983), S. 4340-4340 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 5859-5861 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The narrow-track perpendicular magnetic heads with multilayered CoZrCr/Ti main-pole films developed here reproduce output signals having increased stability as the number of pairs of CoZrCr layers increases. To see why, a Kerr-effect apparatus was used to measure the relationship between dynamic domain behavior and the number of pairs of CoZrCr layers for multilayered narrow CoZrCr/Ti stripes of different widths. Increasing the number of pairs of CoZrCr layers suppressed wall displacement and stabilized the domain structure. The domain stability agreed fairly well with the stability in perpendicular heads having multilayered CoZrCr/Ti main-pole films.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 6055-6057 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The magnetoresistance (MR) ratio of a ferromagnetic tunnel junction with a spin-valvelike structure of NiFe/CoFex/Al–O/CoFex/NiFe/IrMn/Al is dependent upon CoFe composition. MR ratio increases with increasing Fe content, and shows a maximum of 42% for Fe content 26 at. % after annealing at 225 °C. Before annealing, the bias voltage dependence depend on Fe content, however, the bias voltage dependence did not depend on Fe content after annealing. We think that the increasing defect states in the barrier layer with the increasing Fe content in CoFex layer cause the degradation of the bias voltage dependence. After annealing, the defect states of samples decrease to same level, and the bias voltage dependencies of samples are improved and become same. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 28 (1987), S. 445-447 
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: The radiative correction of nonlinear sigma models on supermanifolds that have invertible metrics is investigated. It will be shown that the equation of motion for Riemannian supergravity (nonstandard supergravity) is derived from a consistency condition. This condition can be satisfied in the case of supergroup manifolds. We shall explicitly construct the model following the methods of Braaten, Curtright, and Zachos [E. Braaten, T. L. Curtright, and C. K. Zachos, Nucl. Phys. B 260, 630 (1985)] and of Witten [E. Witten, Commun. Math. Phys. 92, 455 (1984)]. Finally, super-Kac–Moody algebras of these models are derived.
    Type of Medium: Electronic Resource
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