ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Fluid inclusions  (7)
  • 05.08. Risk  (4)
  • Elsevier  (11)
  • American Association of Petroleum Geologists (AAPG)
  • American Meteorological Society
  • Potsdam Institute for Climate Impact Research
  • 2020-2024  (11)
  • 1995-1999
Sammlung
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
Jahr
  • 1
    facet.materialart.
    Unbekannt
    Magma storage and degassing beneath the youngest volcanoes of the Massif Central (France): Lessons for the monitoring of a dormant volcanic province (2023)
    Elsevier
    Details
    Publikationsdatum: 2023-10-03
    Beschreibung: Developing appropriate monitoring strategies in long-quiescent volcanic provinces is challenging due to the rarity of recordable geochemical and geophysical signals and the lack of experienced eruptive phenomenology in living memory. This is the case in the Massif Central (France) where the last eruptive sequence formed the Pavin’s Group of Volcanoes, about 7 ka ago. There, current evidence of a mantle activity reminiscence is suggested by the presence of mineral springwaters, mofettes, and soil degassing. It appears fundamental as a prerequisite to decipher the evolution of the gas phase in the magmatic system at the time of the eruptive activity to understand the meaning of current local gas emissions. In this study, we develop an innovative approach coupling CO2 densimetry and geochemistry of fluid inclusions from products erupted by the Pavin’s Group of Volcanoes. 3D imagery by Raman spectroscopy revealed that carbonate forming in fluid inclusions may lead to underestimation of CO2 density in fluid inclusions by up to 50 % and thus to unreliable barometric estimates. Fortunately, we found that this effect may be limited by focusing on fluid inclusions with a small diameter (〈4 m) and where no solid phase is detected on Raman spectra. The time evolution of the eruptions of the Pavin’s Group of Volcanoes shows a progressive decrease of the pressure of magma storage (from more than 9 kbar down to 1.5-2 kbar) in parallel to magma differentiation (from basanites at Montcineyre to benmoreites at Pavin). The analysis of the noble gases entrapped in fluid inclusions yielded two main conclusions: (1) the helium isotope signature (Rc/Ra = 6.5-6.8) is in the range of values obtained in fluid inclusions from mantle xenoliths in the Massif Central (Rc/Ra = 5.6±1.1, on average) suggesting partial melting of the subcontinental lithospheric mantle, and (2) magma degassing (4He/40Ar* from 4.0 to 16.2) mirrors magma differentiation and the progressive rise of the magma ponding zones of the Pavin’s Group of Volcanoes. According to our modelling, about 80 % of the initial gas phase would be already exsolved from these magmas, even if stored at mantle depth. Based on the results obtained from fluid inclusions, we propose a model of the evolution of the signature of noble gases and carbon isotopes from mantle depth to crustal levels. In this frame, gas emissions currently emitted in the area (Rc/Ra = 6.1-6.7 and 4He/40Ar* = 1.7) point to an origin in the lithospheric mantle. This study strongly encourages the establishment of a regular sampling of local gas emissions to detect potential geochemical variations that may reflect a change from current steady-state conditions
    Beschreibung: Published
    Beschreibung: 121603
    Beschreibung: 1V. Storia eruttiva
    Beschreibung: 2V. Struttura e sistema di alimentazione dei vulcani
    Beschreibung: 5V. Processi eruttivi e post-eruttivi
    Beschreibung: JCR Journal
    Schlagwort(e): Fluid inclusions ; Barometry ; Noble gases ; Magma degassing ; Monitoring ; 04.08. Volcanology ; 04.01. Earth Interior
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 2
    facet.materialart.
    Unbekannt
    Building climate resilience through nature-based solutions in Europe: A review of enabling knowledge, finance and governance frameworks (2023)
    Elsevier
    Details
    Publikationsdatum: 2023-03-01
    Beschreibung: The European Union (EU) has firmly positioned itself as a global leader in promoting and implementing nature-based solutions (NBS). The recently released EU Biodiversity Strategy for 2030, Strategy on Adaptation to Climate Change, and Forest Strategy - all representing key pillars of the ambitious European Green Deal (EGD) - rely on NBS to both preserve and restore ecosystem integrity and increase climate resilience. Although research and policy in Europe have advanced the conceptualization and operationalization of NBS, a much wider adoption is needed to reach the ambitious goals of the EGD and fulfil its vision of transforming into a sustainable, climate-neutral, climate resilient, fair, and prosperous EU by 2050. In this paper, we review recent EU-supported research, policy, and practices to identify critical dimensions that still need to be addressed for greater uptake of NBS. While recognising the multiple societal challenges NBS can target, we build on the key messages from the ‘5th European Climate Change Adaptation conference ECCA 2021′ and focus our analysis on NBS for climate change adaptation and disaster risk reduction. We screen a wide range of NBS cases across the EU and identify-three core challenges to implementation: the lack of a comprehensive evidence base on the effectiveness of NBS to address targeted challenges; the need for a greater involvement of the private sector in financing NBS; and opportunities for enhancing stakeholder engagement in the successful design and implementation of NBS. We take these challenges as the starting point for a broader reflection and critical discussion on the role of i) knowledge, i) finance, including investments in NBS and divestments from nature-negative projects, and iii) governance and policy frameworks to enable the uptake of NBS. We conclude by identifying options for the EU to foster the uptake of NBS in research, policy and practice.
    Beschreibung: Published
    Beschreibung: 100450
    Beschreibung: 4A. Oceanografia e clima
    Beschreibung: JCR Journal
    Schlagwort(e): Nature-based solutions ; European Union ; European Green Deal ; Climate change adaptation ; Disaster risk reduction ; 05.08. Risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 3
    facet.materialart.
    Unbekannt
    Relative seismic and tsunami risk assessment for Stromboli Island (Italy) (2023)
    Elsevier
    Details
    Publikationsdatum: 2023-03-02
    Beschreibung: An innovative method of estimating the relative risk of buildings exposed to seismic and tsunami hazards in volcanic islands is applied to Stromboli (Italy), a well-known stratovolcano affected by moderate earthquakes and mass-flow-induced tsunamis. The method uses a pre-existing quali-quantitative analysis to assess the relative risk indices of buildings, which provide comparative results useful for prioritisation purposes, in combination with a historical-geographical settlement analysis consistent with the ‘territorialist’ approach to the urban and regional planning and design. The quali-quantitative analysis is based on a new proposed survey-sheet model, useful to collect building information necessary for the relative risk estimation, whereas the historical-geographical investigation is based on the multi-temporal comparison of aerial and satellite images. The proposal to combine two consolidated methods represents an innovation in estimating relative risk. Considering that Stromboli Island had never been subjected to similar analyses, the results of the relative seismic risk assessment are novel and moreover identify buildings with a fairly-low and spatially-uniform relative risk. The results of the relative tsunami risk assessment are consistent with results of similar past studies, identifying buildings with a higher relative risk index on the northern coast of the island. The combined use of a building-by-building survey with a multi-temporal analysis of settlements allows obtaining a higher detail than previously available for the region. If adequately modified, the proposed combination of methods allows assessing relative risk also considering other geo-environmental hazards and their cascading effects, in a multi-hazard risk assessment perspective.
    Beschreibung: Published
    Beschreibung: 103002
    Beschreibung: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Beschreibung: JCR Journal
    Schlagwort(e): Relative risk assessment ; Seismic risk ; Tsunami risk ; Volcanic islands ; Stromboli ; Aeolian archipelago ; 05.08. Risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 4
    facet.materialart.
    Unbekannt
    Seawater intrusion and hydrogeochemical processes in the Ischia Island groundwater system (2023)
    Elsevier
    Details
    Publikationsdatum: 2023-03-16
    Beschreibung: Ischia is a volcanic island located NW of the Gulf of Naples (South Italy). The island of Ischia is a structurally complex hydrothermal active system that hosts a fractured aquifer system whose geometry and hydraulic properties are still partly unknown. The aquifer system of Ischia, composed mainly of Quaternary volcanic deposits and marine sediments, exhibits physically and chemically heterogeneous waters. The intense seismicity and hydrothermal activity are expressed by numerous fumaroles and thermal springs, which have been exploited since ancient times, promoting, and supporting the world-renowned tourist activities that constitute the main economic activity of the island. The aim of this study is to determine the hydrogeochemical processes in the Ischia aquifer system. Also, we calculated the proportion of seawater in the aquifer system of Ischia using historical hydrogeochemical data relative to two sampling campaigns. Sixty-nine groundwater and thermal spring samples collected in July 2000 were analyzed and compared with previously published data to identify the changes in seawater contribution. The sample analysis shows that different physicochemical processes occur in the groundwater of Ischia Island, where recharge water, seawater and deep fluids interact and overlap with different intensity. The calculated saline factor indicates a seawater content of up to 70% in some samples near the coast, suggesting that seawater intrusion is the main process in these areas. Later data show that seawater intrusion increases around the coastline with up to 93% seawater content. Finally, data analysis shows that although a change in chemical composition is observed, no variation in thermal water temperature is recorded over time.
    Beschreibung: This paper is partially funded by Program U-Apoya (N/A1/2014), University of Chile who granted Dr. Linda Daniele and by project PCI ITAL170012. Additional funding was provided by project M02761 Ministero degli Affari Esteri e della Cooperazione Internazionale to Renato Somma and by ANID-FONDAP #15200001/ACE210005 (Centro de Excelencia en Geotermia de los Andes, CEGA). Finally, we acknowledge chief editor Stefano Albanese for handling the manuscript. An anonymous reviewer is acknowledged for the helpful comments and suggestions.
    Beschreibung: Published
    Beschreibung: 106935
    Beschreibung: 9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche
    Beschreibung: 1V. Storia eruttiva
    Beschreibung: 6A. Geochimica per l'ambiente e geologia medica
    Beschreibung: 1TR. Georisorse
    Beschreibung: 6SR VULCANI – Servizi e ricerca per la società
    Beschreibung: 2IT. Laboratori analitici e sperimentali
    Beschreibung: JCR Journal
    Schlagwort(e): Seawater intrusion ; Water-rock interaction ; Thermal waters ; Ischia Island ; 04.08. Volcanology ; 03. Hydrosphere ; 03.02. Hydrology ; 05.08. Risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 5
    facet.materialart.
    Unbekannt
    Arsenic contamination at the Bagnoli Bay seabed (South Italy) via particle tracking numerical modeling: Pollution patterns from stationary climatic forcings (2023)
    Elsevier
    Details
    Publikationsdatum: 2023-03-16
    Beschreibung: Almost 140 years of industrial exploitation have severely degraded the environment of Bagnoli Coroglio (BC), the westernmost neighborhood of the city of Naples (Italy). In this peculiar area, however, geogenic processes overlap with the impact of human activities, making it difficult to distinguish between anthropogenic and geogenic pollution sources. This is particularly true for Arsenic, the concentration of which in the marine sediments largely exceeds the tolerable level for human health and the background value for local pyroclastics. After several studies have used traditional tools based on multivariate statistics, this article attempts at tackling the problem via numerical modeling, which provides a deeper insight into the physics that governs the pollution process. Therefore, we use a particle tracking model to assess whether arsenic levels in the seabed can be affected by the influx of thermal water from an artificial channel outfalling at the westernmost part of the coast The climatic forcings that drive the marine circulation are simplified to basic "scenarios", in which wind and waves are stationary in strength and direction. Since the simulation time is much less than the contamination timescale, the comparison between numerical results and measurements is essentially qualitative and concerns the shape of contamination contours. It was found the primary forcing that enables seabed pollution is the tidal circulation, which, moreover, acts continuously in time. Quantitative arguments based on regression analysis suggest the discharge of thermal water explains almost a quarter of the observed pollution, which is consistent with previous research based on multivariate statistics.
    Beschreibung: This research results from a collaboration between the University of Naples Federico II and the National Institute of Geophysics and Vulcanology (INGV). The partnership is born in the frame of the multidisciplinary project ABBaCo, funded by the Italian Ministry of Education and Research, which aimed to provide innovative and environmentally friendly solutions for restoring the Bagnoli area.
    Beschreibung: Published
    Beschreibung: 134955
    Beschreibung: 9T. Geochimica dei fluidi applicata allo studio e al monitoraggio di aree sismiche
    Beschreibung: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Beschreibung: 6A. Geochimica per l'ambiente e geologia medica
    Beschreibung: 1TR. Georisorse
    Beschreibung: 7SR AMBIENTE – Servizi e ricerca per la società
    Beschreibung: 2IT. Laboratori analitici e sperimentali
    Beschreibung: JCR Journal
    Schlagwort(e): Adsorption ; Arsenic contamination in marine sediments ; Diffusion in coastal waters ; Numerical modeling ; Particle tracking ; Sediments settling ; 03. Hydrosphere ; 03.02. Hydrology ; 03.04. Chemical and biological ; 04.04. Geology ; 04.08. Volcanology ; 05.08. Risk ; 05.06. Methods
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 6
    facet.materialart.
    Unbekannt
    Petrological and noble gas features of Lascar and Lastarria volcanoes (Chile): Inferences on plumbing systems and mantle characteristics (2020)
    Elsevier
    Details
    Publikationsdatum: 2023-11-16
    Beschreibung: Lascar (5592 m a.s.l.) and Lastarria (5697 m a.s.l.) are Chilean active stratovolcanoes located in the Central Volcanic Zone (CVZ; 16°S to 28°S) that have developed on top of a 71 km thick continental crust. Independently of the similarities in their Plinian/Vulcanian eruptive styles, their complex magmatic feeding structures and the origins of their magmatic fluids still necessitate constraints in order to improve the reliability of geochemical monitoring. Here we investigate the petrography, bulk-rock chemistry, and mineral chemistry in products from the 1986–1993 explosive eruptive cycle at Lascar and from several Holocene eruptive sequences at Lastarria. These data are integratedwith measurements of the noble gas isotopes in fluid inclusions (FIs) of minerals fromthe same products as well as in fumarole gases. The geochemistry ofminerals and rocks shows that the studied products belong to high-K–calc-alkaline series typical of subduction-related settings, and provide evidence of differentiation,mixing, and crustal assimilation that are higher at Lastarria. The contribution of slab sediments and fluids to magma genesis in thewedge is limited, suggesting a homogeneous mantle beneath CVZ. The deepest crystallization processes occurred at variable levels of the plumbing systems according to the lithostatic equivalent depths estimated with mineral equilibrium geobarometers at Lascar (15–29 km) and Lastarria (~20–40 km). The 40Ar/36Ar and 4He/20Ne ratios in FIs and fumarole gases indicate the presence of some degree of air contamination in the fluids from both volcanoes. The 3He/4He values at Lascar (6.9–7.3 Ra) are relatively homogeneous and comparable to those of fumaroles, suggesting a main zone of magma crystallization and degassing. In contrast, the 3He/4He values at Lastarria (5.31–8.01 Ra) vary over a wide range, suggesting various magma storage levels and providing evidence of crustal contamination, as indicated by the rock chemistry.We argue thatmantle beneath the two volcanoes has a MORB-like signature of 3He/4He, while local crustal contamination explains the lower ratios measured at Lascar.
    Beschreibung: Published
    Beschreibung: 105615
    Beschreibung: 1V. Storia eruttiva
    Beschreibung: 2V. Struttura e sistema di alimentazione dei vulcani
    Beschreibung: JCR Journal
    Schlagwort(e): Lascar ; Lastarria ; noble gases ; Fluid inclusions ; Crustal contamination ; Mantle wedge ; 04.08. Volcanology ; 04.01. Earth Interior
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 7
    facet.materialart.
    Unbekannt
    Noble gas magmatic signature of the Andean Northern Volcanic Zone from fluid inclusions in minerals (2020)
    Elsevier
    Details
    Publikationsdatum: 2023-11-21
    Beschreibung: Trace volatile elements like He are key for understanding the mantle source signature of magmas and to better constrain the relative roles of subduction and crustal processes to the variability of along-arc chemical and isotopic signatures of magmatic fluids. Here we report on noble gas abundances and isotopic data of Fluid Inclusions (FIs) in eruptive products and/or fumarolic gases from the Colombia-Ecuador segment of Andean Northern Volcanic Zone (NVZ). FIs in olivine phenocrysts from Ecuador (El Reventador, Cotopaxi and Tungurahua) yield air-normalized corrected 3He/4He ratios of 7.0–7.4 RA, within the MORB range (8 ± 1 RA). With exception of the Cotopaxi lavas (opx 〈 〈oliv.), these are indistinguishable of those obtained for their cogenetic orthopyroxene pairs and of gas emissions previously reported in literature. Olivine phenocrysts from Nevado del Ruiz fissure lavas also yield the highest 3He/4He (8.5 ± 0.3 RA) for this volcanic system, which is in the range of fumarolic gases for Galeras (previously reported as high as 8.8 RA and here measured to a maximum of 8.3 ± 0.1 RA). Our dataset highlights disparities between isotope signatures of eruptive products from Ecuador (avg. ~7.2 RA) and those reported for the Colombian portion of the NVZ (avg. ~8.5 RA). Previous studies on the geochemistry of erupted products put in evidence significant along-arc variations ascribed either to the involvement of different slab components, or to variable depths of evolution of arc magmas within the continental crust. However, the same variation is not discernible in the signature of noble gases, especially helium, from FIs and gas emissions analyzed in this study, with little inter-variation between Cotopaxi, Reventador and Tungurahua (all within 0.2 RA from the Ecuador average of 7.2) and Galeras and Nevado del Ruiz, whose maximum values differ by ~0.3 RA. We therefore suggest a homogenous MORB-like 3He/4He signature for the mantle wedge beneath this arc segment, whereby along-arc variations in crustal thickness (from 〈35 km at the northernmost part of the segment to ≥50 km at the Ecuadorian arc segment) may factor largely into the variability recorded on our data set. The first CO2/3He ratios obtained in FIs from Andean rocks support the hypothesis of increasing crustal contamination from Colombia to Ecuador, concomitant with increasing crustal thicknesses under the respective arc regions.
    Beschreibung: Published
    Beschreibung: 119966
    Beschreibung: 1V. Storia eruttiva
    Beschreibung: 2V. Struttura e sistema di alimentazione dei vulcani
    Beschreibung: 4V. Processi pre-eruttivi
    Beschreibung: JCR Journal
    Schlagwort(e): Andean Volcanic Belt ; Northern Volcanic Zone ; Fluid inclusions ; Noble gases ; Helium ; Crustal thickness ; 04.08. Volcanology ; 04.01. Earth Interior
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 8
    facet.materialart.
    Unbekannt
    The composition of fluids stored in the central Mexican lithospheric mantle: Inferences from noble gases and CO2 in mantle xenoliths (2021)
    Elsevier
    Details
    Publikationsdatum: 2023-11-16
    Beschreibung: We present the first isotopic (noble gases and CO2) characterization of fluid inclusions coupled to Raman microspectroscopy analyses in mantle xenoliths from Central Mexico, a geodynamically complex area where the Basin and Range extension was superimposed on the Farallon subduction (terminated at 28 Ma). To characterize the isotopic signature of the Central Mexican lithospheric mantle, we focus on fluid inclusions entrapped in mantle xenoliths found in deposits of the Joya Honda maar (JH), a Quaternary monogenetic volcano belonging to the Ventura Espiritu Santo Volcanic Field (VESVF) in the state of San Luis Potosí (central Mexico). Thirteen ultramafic plagioclase-free xenoliths were selected, all exhibiting a paragenesis Ol 〉 Opx 〉 Cpx 〉 〉 Sp, and being classified as spinel-lherzolites and harzburgites. All xenoliths bring textural evidence of interstitial glass veins bearing dendritic trails of secondary melt and fluid inclusions (composed of silicate glass ± CO2 ± Mg-Ca carbonates ± pyrite). These are related to pervasive mantle metasomatism driven by carbonate-rich silicate melt. The Ar and Ne systematics reflect mixing between MORB-like upper mantle and atmospheric fluids, the latter interpreted as reflecting a recycled air component possibly inherited from the Farallon plate subduction. The 3He/4He ratios vary between 7.13 and 7.68 Ra, within the MORB range (7–9 Ra), and the 4He/40Ar* ratios (0.4–3.11) are similarly close to the expected range of the fertile mantle (1–5). Taken together, these pieces of evidence suggest that (i) either the mantle He budget was scarcely modified by the Farallon plate subduction, and/or (ii) that any (large) crustal contribution was masked by a later metasomatism/refertilization episode, possibly during the subsequent Basin and Range extension. A silicate melt-driven metasomatism/refertilization (revealed by the association between glass veins and fluid inclusions) is consistent with calculated helium residence time for the Mexican lithospheric mantle (20 to 60 Ma) that overlaps the timing of the above geodynamic events. We propose that, after the refertilization event (e.g., over the last ~20 Ma), the lithospheric mantle has evolved in a steady-state, becoming slightly more radiogenic. We also estimated 3He fluxes (0.027–0.080 mol/g), 4He production rates (340–1000 mol/yr), and mantle CO2 fluxes (3.93 × 107 mol/yr to 1.18 × 108 mol/yr) using the helium isotopic values measured in JH mantle xenoliths. Finally, the JH xenoliths exhibit CO2/3He ratios comparable to those of the upper mantle (from 3.38 × 108 to 3.82 × 109) but more positive δ13C values (between - 1.0 and - 2.7‰), supporting the involvement of a crustal carbonate component. We propose that the metasomatic silicate melts recycled a crustal carbonate component, inherited by the Farallon plate subduction.
    Beschreibung: Published
    Beschreibung: 120270
    Beschreibung: 2V. Struttura e sistema di alimentazione dei vulcani
    Beschreibung: JCR Journal
    Schlagwort(e): Mexican mantle xenoliths ; Fluid inclusions ; Noble gases ; CO2 ; mantle refertilization ; Carbonate recycling ; 04.01. Earth Interior ; 04.08. Volcanology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 9
    facet.materialart.
    Unbekannt
    Recycled crustal carbon in the depleted mantle source of El Hierro volcano, Canary Islands (2021)
    Elsevier
    Details
    Publikationsdatum: 2023-11-16
    Beschreibung: The Canary Islands, in the eastern Atlantic, are among the most enigmatic Oceanic Island provinces on Earth, as the mantle source feeding its volcanism exhibits wide spatial heterogeneity and a multiplicity of sources. Multiisotope whole-rock studies have long revealed the presence of a recycled oceanic crust/lithosphere component in the mantle source. However, noble gas systematics have been more challenging to interpret, and the available carbon isotope data is limited and cannot support/dismiss this interpretation. Here, we present the very first isotopic characterisation of CO2 and noble gases (He-Ne-Ar) in fluid inclusions (FI) in minerals hosted in mantle xenoliths from El Hierro, the youngest and westernmost island of the Canary volcanic archipelago. Six fresh xenoliths from El Julan cliff valley were analysed (3 spinel lherzolites and 3 spinel harzburgites). We find carbon isotopic compositions of CO2 in FI (δ13C) ranging from 􀀀 2.38 to 􀀀 1.23‰ in pyroxenes and from 􀀀 0.19 to +0.96‰ in olivines. These unusually positive δ13C values, well above the typical mantle range (􀀀 8‰ 〈 δ13C 〈 􀀀 4‰), prove, for the first time, the presence of a recycled crustal carbon component in the local source mantle. We interpret this 13C-rich component as inherited from a mantle metasomatism event driven by fluids carrying carbon from C. In contrast, our El Hierro xenoliths identify a depleted mantle-like He signature, with an average Rc/Ra ratio (3He/4He normalised to air ratio and corrected for atmospheric contamination) of 7.45 ± 0.26 Ra. The involvement of depleted mantle-like fluids, variably admixed with air-derived components (possibly recycled via paleo-subduction event(s)), is corroborated by Ne-Ar isotopic compositions. The depleted mantle-like He signature suggests instead the involvement of a primordial He source in the local lithospheric mantle and indicates a marginal role played by past subduction events in modifying the local mantle He budget. When put in the context of previous 3He/4He measurements in FI and surface gases along the Canary archipelago, our results confirm an overall west-to-east decrease of Rc/Ra ratios, which may be interpreted as due to increasing contributions from the African sub-continental mantle, the addition of radiogenic 4He during magma migration in the oceanic crust (whose thickness increases eastward) and/or magma ageing.
    Beschreibung: Published
    Beschreibung: 106414
    Beschreibung: 1V. Storia eruttiva
    Beschreibung: 2V. Struttura e sistema di alimentazione dei vulcani
    Beschreibung: JCR Journal
    Schlagwort(e): Canary Islands ; El Hierro ; Mantle xenoliths ; Fluid inclusions ; Recycled carbon ; noble gases ; 04.08. Volcanology ; 04.01. Earth Interior
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 10
    facet.materialart.
    Unbekannt
    The noble gas signature of the 2021 Tajogaite eruption (La Palma, Canary Islands) (2024)
    Elsevier
    Details
    Publikationsdatum: 2024-05-06
    Beschreibung: Here, we characterize the temporal evolution of volatiles during the Tajogaite eruption by analyzing the elemental (He-Ar-CO2-N2) and isotopic (He-Ar-Ne) composition of fluid inclusions (FI) in phenocrysts (olivine+ pyroxene) identified in erupted lavas. Our 2021 lava samples identify substantial temporal variations in volatile composition. We show that, during the 2021 Tajogaite eruption, the He-CO2-N2 concentrations in FI increased since October 15th; this increase was accompanied by increasing 40Ar/36Ar ratios (from ~300 to 〉500), and paralleled a major shift in bulk lava chemistry, with increasing Mg contents (Mg#, from 47 to 52 to 55–59), CaO/Al2O3 (from 0.65 to 0.74 to 0.75–0.90), Ni and Cr, and decreasing TiO2, P2O5 and incompatible elements. The olivine core composition also became more forsteritic (from Mg# = 80–81 to Mg# = 84–86). Mineral thermobarometry and FI barometry results indicate that the eruption was sustained by magmas previously stored in at least two magma accumulation zones, at respectively ~6–12 km and 15–30 km, corroborating previous seismic and FI evidence. We therefore propose that the compositional changes seen throughout the eruption can be explained by an increased contribution - since early/mid-October - of more primitive, less degassed magma from the deeper (mantle) reservoir. Conversely, Rc/Ra values (3He/4He ratios corrected for atmospheric contamination) remained constant throughout the whole eruption at MORB-like values (7.38 ± 0.22 Ra, 1σ), suggesting an isotopically homogeneous magma feeding source. The Tajogaite He isotope signature is within the range of values observed for the 1677 San Antonio lavas (7.37 ± 0.17Ra, 1σ), but is more radiogenic than the 3He/4He values (〉9 Rc/Ra) observed in the Caldera de Taburiente to the north. The 3He/4He ratios (6.75 ± 0.20 Ra, 1σ) measured in mantle xenoliths from the San Antonio volcano indicate a relatively radiogenic nature of the mantle beneath the Cumbre Vieja ridge. Based on these results and mixing modeling calculations, we propose that the homogeneous He isotopic signatures observed in volatiles from the Tajogaite/San Antonio lavas reflect three component mixing between a MORB-like source, a radiogenic component and small additions (6–15%) of a high 3He/4He reservoir-derived (〉9Ra) fluid components. The simultaneous occurrence of high 3He/4He (〉9Ra)- and MORB-like He signatures in northern and southern La Palma is interpreted to reflect small-scale heterogeneities in the local mantle, arising from spatially variable proportions of MORB, radiogenic, and high 3He/4He components.
    Beschreibung: Published
    Beschreibung: 107928
    Beschreibung: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Beschreibung: JCR Journal
    Schlagwort(e): La Palma ; 2021 Tajogaite eruption ; Fluid inclusions ; Noble gas ; Magma feeding system ; Mantle source heterogeneity ; 04.08. Volcanology ; 04.01. Earth Interior
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
  • 11
    facet.materialart.
    Unbekannt
    Geochemical evidence for a lithospheric origin of the Comoros Archipelago (Indian Ocean) as revealed by ultramafic mantle xenoliths from La Grille volcano (2024)
    Elsevier
    Details
    Publikationsdatum: 2024-01-12
    Beschreibung: Petrology and fluid inclusions (FI) geochemistry are increasingly used in tandem to constrain the compositional features and evolution of the lithospheric mantle. In this study, we combine petrography and mineral chemistry with analyses of noble gases (He, Ne and Ar) and CO2 in olivine, orthopyroxene- and clinopyroxene-hosted FI, as well as radiogenic isotope (Sr-Nd-Pb) systematics of ultramafic xenoliths collected at La Grille volcano in Grande Comore Island, aiming at better characterizing one of the most enigmatic and controversial portions of the western Indian Ocean lithospheric mantle. Xenoliths have been divided in three groups on the basis of their textural features: Group 1 (Opx-bearing), Group 2 (Opx-free) and Group 3 (Cumulate). Overall, petrographic observations and mineral phase compositions indicate that the sampled lithospheric portion experienced variable degrees of melting (from 5% to 35%), recorded by Group 1 most refractory harzburgites and lherzolites, as well as modal metasomatic processes as evidenced by the crystallization of cpx at the expense of opx in Group 1 fertile lherzolites and wehrlite and by Group 2 xenoliths. Crystallization of slightly oversaturated basic silicate melts seems also to have occurred, as shown by Group 3 xenoliths. A positive trend between temperature and ƒO2 is evident, with Group 2 and 3 xenoliths testifying for hotter and more oxidised conditions than Group 1. The variability of the 4He/40Ar* ratio (0.02–0.39) in Group 1, significantly below typical values of a fertile mantle (4He/40Ar* = 1–5), can be explained by the variable degrees of partial melting coupled to metasomatic enrichment that may account for modifying 4He/40Ar*, as also indicated by the mineral composition. He-Ar-CO2 relationships support the presence of a metasomatic CO2-rich process post-dating the melt extraction and the cumulate formation. The air-corrected 3He/4He isotopic ratios (6.30 to 7.36 Ra) are intermediate between the MORB mantle signature (8 ± 1Ra) and the SCLM (6.1 ± 0.9 Ra). The Ne and Ar isotopic signatures (20Ne/22Ne, 21/Ne/22Ne and 40Ar/36Ar) are consistent with mixing between an air-derived component and a MORB-like mantle, supporting the hypothesis for a lithospheric origin of the Comoros magmas, and arguing against any deep mantle plume-related contribution. This is also corroborated by combining Ne with He isotopes, showing that La Grille ultramafic xenoliths are far from the typical plume-type compositions. Sr-Nd-Pb isotope systematics in opx and cpx from La Grille additionally support a MORB-type signature for the lithospheric mantle beneath the area.
    Beschreibung: Published
    Beschreibung: 107406
    Beschreibung: OSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametrici
    Beschreibung: JCR Journal
    Schlagwort(e): Mantle xenoliths ; Noble gases ; Fluid inclusions ; Radiogenic isotopes
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    ARTIKEL (OA)
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...