ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
  • Akadémiai Kiadò  (2)
  • Elsevier B.V.  (2)
Collection
Keywords
Publisher
Years
  • 1
    facet.materialart.
    Unknown
    Helium isotopes distribution in NW Iberian peninsula: evidences of a local neotectonic activity (2012)
    Akadémiai Kiadò
    Details
    Publication Date: 2021-01-27
    Description: In this work we report new data on He abundances and isotope ratios (3He/4He) from gas associated to some thermal and CO2-rich mineral waters in N-Portugal. Collected gas samples are mainly CO2-dominant except two sites where gas is N2-rich. All the sampling sites are characterized by exceptionally high helium contents with 3He/4He ratios, corrected for air contamination, varying considerably from 0.09 to 2.68 Ra. In all sites, the 3He/4He ratios are higher than that typical for stable continental areas thus indicating a variable but not-negligible (up to 30%) contribution of mantle-derived primordial He. In all the CO2-rich waters, CO2/3He ratios and 13CCO2 are comparable with mantle values, thus suggesting a magmatic origin also for CO2. On the contrary, in the N2-rich waters He is mainly radiogenic, and CO2 is organic in origin. Since no recent volcanic activity is observed in NW Iberia, high 3He/4He values could be due, at least, to three processes: a) releasing of gas from the local upper mantle through deep extensional fault systems; b) releasing of magmatic volatiles from crustal reservoir(s) formed during past volcanic activity; c) degassing of a subsurface emplaced magma body. Mantle He flux in N-Portugal has been estimated to be up to 3 orders of magnitude higher than that typical for stable continental areas, thus suggesting, in this area, the presence of a tensional tectonic regime. This implies that mantle gases could migrate upward probably through inherited tectonic structures reactivated by neotectonic activity. The third possible scenario seems to be less plausible since seismic surveys carried out in NW Iberian did not find any significant evidence of mantle intrusion in the crust. The observed spatial variability in mantle-derived contribution could reflect the geometry of the granitic plutons in this area, thus supporting the hypotheses of an upper mantle degassing. Alternatively, it could be the result of a lateral migration of magmatic volatiles stored in a crustal reservoir.
    Description: Published
    Description: Budapest, Hungary
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: open
    Keywords: Helium isotopes ; NW Iberian peninsula ; 03. Hydrosphere::03.04. Chemical and biological::03.04.03. Chemistry of waters ; 03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases ; 03. Hydrosphere::03.04. Chemical and biological::03.04.07. Radioactivity and isotopes ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Insights into fluid circulation across the Pernicana Fault (Mt. Etna, Italy) and implications for flank instability (2010)
    Elsevier B.V.
    Details
    Publication Date: 2017-04-04
    Description: We conducted geophysical–geochemical measurements on a ∼2 kmN–S profile cutting across the Pernicana Fault, one of the most active tectonic features on the NE flank of Mt. Etna. The profile passes from the unstable E flank of the volcano (to the south) to the stable N flank and significant fluctuations in electrical resistivity, self-potential, and soil gas emissions (CO2, Rn and Th) are found. The detailed multidisciplinary analysis reveals a complex interplay between the structural setting, uprising hydrothermal fluids, meteoric fluids percolating downwards, ground permeability, and surface topography. In particular, the recovered fluid circulation model highlights that the southern sector is heavily fractured and faulted, allowing the formation of convective hydrothermal cells. Although the existence of a hydrothermal system in a volcanic area does not surprise, these results have great implications in terms of flank dynamics at Mt. Etna. Indeed, the hydrothermal activity, interacting with the Pernicana Fault activity, could enhance the flank instability. Our approach should be further extended along the full extent of the boundary between the stable and unstable sectors of Etna for a better evaluation of the geohazard in this active tectonic area.
    Description: This work was partly financed by the DPC-INGV FLANK and LAVA Projects.
    Description: Published
    Description: 137–142
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: 3.2. Tettonica attiva
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: JCR Journal
    Description: reserved
    Keywords: Pernicana Fault ; fluid circulation ; structural geology ; Etna ; magnetic ; electrical methods ; 04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous ; 04. Solid Earth::04.02. Exploration geophysics::04.02.01. Geochemical exploration ; 04. Solid Earth::04.02. Exploration geophysics::04.02.04. Magnetic and electrical methods ; 04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods ; 04. Solid Earth::04.02. Exploration geophysics::04.02.07. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.04. Thermodynamics ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.08. Risk::05.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Stable isotope feature of groundwaters from Graciosa volcanic Island (Azores) – preliminary results (2012)
    Akadémiai Kiadò
    Details
    Publication Date: 2012-02-03
    Description: The Azores archipelago is made of nine islands all of volcanic origin and a few islets located in the North Atlantic Ocean, about 1800 km west of Portuguese mainland at the triple junction of the Eurasian, North American and Nubian plates (Azores Triple Junction = ATJ). Graciosa Island is part of the Central Group of Azores archipelago and is located on the Terceira Rift, a major tectonic feature of the ATJ. The main hydrothermal manifestations at Graciosa Island occur in the Caldeira volcano (SE part of the island), and particularly inside the huge (150 m wide, 80 m high) Furna do Enxofre lava cave located in the Caldeira, where a bubbling mud pool releases steam and gases, leading to the accumulation of CO2 at the bottom of the cave, filled by a coldwater subterranean lake. Three field work campaigns were carried out at Graciosa Island and 14 water samples have been collected, from boreholes, springs and the subterranean lake for isotopic (18O, 2H and 3H) and chemical analysis. The groundwater samples were plotted along the GMWL, and two water groups were identified in the 18O vs. 2H diagram. The splitting up of the samples is even more visible when the O-18 content is plotted as a function of the temperature or as a function of the electrical conductivity. Besides the differences in mineralization and temperature observed in the groundwater samples from Graciosa Island, an isotopic shift towards more enriched values is also observed. The salinity and isotopic content seems to indicate not a simple mixture between two end-members, i.e. seawater – fresh water: another process of mineralization and isotope enrichment must be considered in this active volcanic environment. A hypothesis to be formulated is that the source of salts could be associated to mixing with boiling seawater, that by evaporation will be able to: i) increase groundwater salinity, ii) strongly change the 2H content to more enriched values, and iii) absent or limited variation in d18O content.
    Description: Published
    Description: Budapest, Hungary
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: restricted
    Keywords: Water isotope ; Graziosa Island ; 03. Hydrosphere::03.04. Chemical and biological::03.04.03. Chemistry of waters ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Oral presentation
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    A new hydrothermal scenario for the 2006 Lusi eruption, Indonesia. Insights from gas geochemistry (2012)
    Elsevier B.V.
    Details
    Publication Date: 2017-04-04
    Description: The 29th of May 2006 gas and mud eruptions suddenly appeared along the Watukosek fault in the north east of Java, Indonesia. Within a few weeks several villages were submerged by boiling mud. The most prominent eruption site was named Lusi. To date (November 2011) Lusi is still active and a ~7 km2 area is covered by the burst mud breccia. The mechanisms responsible for this devastating eruption remain elusive. While there is consensus about the origin of the erupted mud, the source of water is uncertain, the origin of the gas is unknown and the trigger of the eruption is still debated. In order to shed light on these unknowns, we acquired a wide set of data of molecular and isotopic composition of gas sampled in several Lusi vents, in the surrounding mud volcanoes, in the closest natural gas field (Wunut), and in the hydrothermal vents at the neighbouring volcanic complex in the period 2006–2011. The boiling fluids erupted in the crater zone are apparently CO2-dominated, while colder CH4-dominated and C2–C3 bearing fluids are identified at several sites around the crater zone. Gas genetic diagrams, maturity plots and gas generation modelling suggest that the hydrocarbons are thermogenic (δ¹³C1 up to −35‰; δ¹³C2 up to −20‰), deriving from marine kerogen with maturity of at least 1.5%Ro, for instance in the ~4400 m deep Ngimbang source rocks. CO2 released from the crater and surrounding seeps is also thermogenic (δ¹³C from −15 to −24‰) related to kerogen decarboxylation or thermal CH4 oxidation in deep rocks, although three vents just outside the crater showed an apparent inorganic signature (−7.5 ‰〈 δ¹³C=−0.5‰) associated to mantle helium (R/Ra up to 6.5). High CO2–CH4 equilibrium temperatures (200–400 °C) are typical of thermally altered hydrocarbons or organic matter. The data suggest mainly thermally altered organic sources for the erupted gases, deeper sourced than the mud and water (Upper Kalibeng shales). These results are consistent with a scenario of deep seated (〉4000 m) magmatic intrusions and hydrothermal fluids responsible for the enhanced heat that altered source rocks and/or gas reservoirs. The neighbouring magmatic Arjuno complex and its fluid–pressure system combined with high seismic activity could have played a key role in the Lusi genesis and evolution. Within this new model framework, Lusi is better understood as a sediment-hosted hydrothermal system rather than a mud volcano.
    Description: Published
    Description: 305–318
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: JCR Journal
    Description: reserved
    Keywords: Lusi eruption ; sediment-hosted hydrothermal system ; mud volcanoes ; gas origin ; CO2 and CH4 ; mantle ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...