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  • 2020-2024  (3)
  • 2010-2014  (102)
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  • 1
    Publication Date: 2020-02-12
    Description: Plinian and Ignimbrite deposits represent explosive activity (ca. 17-19 cal ka) within the predominantly effusive and mildly explosive (Strombolian) volcanic history of Mount Etna (Italy). Proximal glasses from the Biancavilla Ignimbrites and Unit D Plinian fall deposits are characterised. Fall deposits recorded at Acireale (D1b and D2b) and Giarre (D1a and D2a) are geochemically distinct confirming they relate to different eruptions. The Acireale Plinian fall (D1b and D2b) deposits compositionally overlap with the Biancavilla Ignimbrite deposits. These explosive eruptions from Etna are considered responsible for widespread ash dispersals throughout the central Mediterranean region, producing the marker tephra layers (Y-1/Et-1) recorded in marine and lacustrine sedimentary archives. Stratigraphically these distal tephras occur at or close to the onset of the last deglaciation (Termination 1) within their respective palaeoenvironmental records, therefore making them potentially crucial tephrostratigraphic markers. This study investigates distal tephra deposits thought to be from Etna recorded in the Ionian Sea (Y-1), Lago Grande di Monticchio (LGdM, Italy; tephras TM-11 and TM-12-1), Lago di Mezzano (Italy) and the Haua Fteah cave (Libya). The glass chemistry of Y-1 tephras recorded in the Ionian Sea and at Haua Fteah are consistent with the Biancavilla Ignimbrites (16,965-17,670 cal yrs BP) and the upper Acireale Plinian fall (D2b). The LGdM record indicates that explosive activity on Etna associated with Unit D spans a minimum of 1540 ± 80 varve years. TM-12-1 (19,200-19,804 cal yrs BP) in LGdM appears to represent the oldest distal counterpart of Etna Unit D explosive activity and is associated with the lower Acireale (D1b) Plinian eruption. The proximally undefined TM-11 (17,640-18,324 cal yrs BP) and distal correlatives are geochemically distinct from the Ionian Sea Y-1 tephra. Such significant compositional differences seen between distal tephra layers are not observed within individual proximal units and are likely to indicate that the distal tephras relate to separate eruptive phases. Until proximal relationships can be established, the TM-11 type Y-1 equivalents should be termed TM-11. Great care should be exercised when using these distal ash layers to synchronise sedimentary records during a crucial period of environmental change.
    Keywords: 550 - Earth sciences
    Type: info:eu-repo/semantics/article
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  • 2
    Publication Date: 2020-02-12
    Type: info:eu-repo/semantics/article
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  • 3
    Publication Date: 2020-02-12
    Description: Laminated sediments of the maar lake Lago Grande di Monticchio in southern Italy exhibit a unique sequence of numerous primary tephra events that provide both insights into the Late Quaternary eruptive history of Italian volcanoes and an archive of essential marker horizons for dating and linking palaeoclimate records throughout the Central and Eastern Mediterranean. The acquisition of new sediment cores from this lake now extends the existing 100 ka-tephra record back to 133 ka BP, the end of the penultimate Glacial. The additional ca 30 m of sediments host a total number of 52 single tephra layers forming 21 tephra clusters that have been characterised on the basis of detailed geochemical and petrographical examinations. Tephras can be assigned to hitherto poorly known Plinian to sub-Plinian eruptive events of the nearby Campanian (Ischia Island, Phlegrean Fields), Roman (Sabatini volcanic district) and Aeolian-Sicilian volcanoes (Etna, Stromboli, Salina) and are dated according to the varve and sedimentation rate chronology of Monticchio sediments. The most prominent tephra layers within the interval of investigation – TM-25 and TM-27 – can be firmly correlated with Ionian Sea tephras X-5 (ca 105 ka BP) and X-6 (ca 108–110 ka BP). In addition, a further 26 tephra layers are correlated with radiometrically and radioisotopically dated volcanic events providing the basis for a robust revised tephrochronology of the entire Monticchio sediment sequence for the last 133 ka.
    Keywords: 550 - Earth sciences
    Type: info:eu-repo/semantics/article
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  • 4
    Publication Date: 2020-02-12
    Type: info:eu-repo/semantics/article
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  • 5
    Publication Date: 2023-02-01
    Description: Geomagnetic excursions represent the dynamic nature of the geodynamo. Accumulated palaeomagnetic records indicate that such excursions are dominated by dipolar-fields, but exhibit different structures. Here we report a palaeomagnetic record from the varved sediments of Lake Suigetsu, central Japan, which reveals fine structures in the Laschamp Excursion and a new post-Laschamp excursion that coincides with the Δ14C maxima. The record’s high-resolution chronology provides IntCal20 mid-ages and varve-counted durations. Both excursions comprise multiple subcentennial directional-swings. Simulations of filtering effects on sediment-magnetisations demonstrate that this high-resolution record replicates most of the features in existing, lower-resolution Laschamp excursion records, including the apparent clockwise open-loop of the virtual geomagnetic pole pass. The virtual geomagnetic poles during the ‘swing’ phases make four clusters centred in hemispherically-symmetric regions, three of which encompass the virtual geomagnetic poles associated with the Laschamp Excursion recorded in lavas at various locations. The stationary dipolar-field sources under each cluster should have intermittently dominated one after another during the excursions.
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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  • 6
    Publication Date: 2024-04-22
    Description: The Campi Flegrei (CF) caldera, in southern Italy, is the source of some of the most powerful Late Pleistocene eruptions of the European sub-continent (e.g., Campanian Ignimbrite, Neapolitan Yellow Tuff eruptions). Although the CF caldera has been continuously and intensively investigated for decades, relatively little is known regarding its earliest volcanic activity. In this work, integrating existing and new tephrostratigraphic data, we provide a comprehensive and updated framework for the CF volcanic activity which has occurred at ∼160 ka and between ∼110 ka and ∼90 ka. The new tephrostratigraphic, geochemical (EMPA + LA-ICP-MS), chronological (40Ar/39Ar dating) and grain-size distribution data relate to CF tephra deposits preserved in mid-proximal (Campanian Plain), distal (Tyrrhenian Sea) and ultra-distal (Lower Danube area) sedimentary archives. Our results allowed us to recognize the presence of at least 13 CF eruptions covering the investigated time frame, with 12 eruptions occurring between 110 and 90 ka. Our high-resolution stratigraphic and chronological investigation also allowed us to recognize that the Triflisco/C-22 tephra, previously considered as a single marker layer, can be actually separated into three different events, sourced from within the CF area in the short time interval of ∼93-90 ka, suggesting a more complex and intense volcanic history than previously thought. Moreover, a Bayesian age-depth model, constrained by previous and new high precision 40Ar/39Ar ages, has led to a reliable estimate of the ages of those undated CF eruptions. Overall, the updated framework on the stratigraphy, chronology, dispersion, and geochemistry of the CF tephra of ∼160 ka and between 110 ka and 90 ka consolidates the notion that the Middle-Late Pleistocene activity in theCF area represents a significant stage of its volcanic evolution, characterised by intense and frequent explosive eruptions.
    Type: info:eu-repo/semantics/article
    Format: application/pdf
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  • 7
    Publication Date: 2024-03-21
    Description: Understanding the temporal and spatial environmental response to past climate change during the Last Glacial-Interglacial Transition (LGIT, 16-8 ka) across Europe relies on precise chronologies for palaeoenvironmental records. Tephra layers (volcanic ash) are a powerful chronological tool to synchronise disparate records across the continent. Yet, some regions remain overlooked in terms of cryptotephra investigations. Building on earlier work at the same sites, we present the first complete LGIT high-resolution cryptotephra investigation of two lake records in the Carpathian Mountains in Romania, Lake Brazi and Lake Lia. Numerous volcanic glass shards have been recognised as originating from various volcanic regions, including: Iceland (Katla, Askja, and Torfajokull), Italy (Campi Flegrei, Ischia, Lipari, and Pantelleria), and central Anatolia (Acigol and Ericyes). In total, four distinct tephra horizons have now been identified in these records: 1) an LGIT Lipari tephra (11,515–12,885 cal BP, 95.4% range); 2) Askja-S (11,070–10,720 cal BP, 95.4% range); 3) an Early Holocene Lipari tephra,(12,590–10,845 cal BP, 95.4% range) and; 4) an Early Holocene Ischia tephra (11,120–10,740 cal BP, 95.4% range). The use of trace element analysis on selected cryptotephra layers provided additional important information in identifying volcanic source and facilitating correlations. These tephra layers, along with numerous other discrete cryptotephra layers, offer promise as significant future isochrons for comprehending the spatial and temporal fluctuations in past climate change throughout Europe and the Mediterranean area. This research has emphasized the significance of the Carpathian region in expanding the European and Mediterranean tephra lattice and establishing it as a keystone area within the framework.
    Type: info:eu-repo/semantics/article
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  • 8
    Publication Date: 2021-12-06
    Description: Major, minor and trace element analysis of volcanic glass in proximal and distal (〈 2 mm) tephra deposits underpins tephrochronology. This approach has been tested in the Aeolian Islands and the Tyrrhenian Sea using juvenile clasts in pyroclastic fall and flow deposits. Geochemical data are used to link marine tephras in the Marsili Basin (core TIR2000-C01) to explosive eruptions of (1) Lipari (Monte Pilato; 776 cal AD); (2) Vulcano; and (3) Campi Flegrei (Soccavo 1; 11,915–12,721 cal years BP). Whether a polymictic coarse grained volcaniclastic turbidite in the Marsili Basin originated from collapse on Salina remains unresolved because multi-elemental analysis raises doubt about the published correlation to the Pollara region. It is evident that correlation of proximal continental and distal marine tephras, at a high level of confidence, requires a full complement of major, minor and trace element data. In conjunction with considerations of the mineralogy and morphology of juvenile deposits these data help define petrological lineages such that precise provenance can be established. Whilst a precise proximal–distal match must be based on identical major, minor and trace element concentrations it is clear that resurgent activity from a single volcano can produce magmas with identical compositions. In such cases stratigraphic relationships must complement any geochemical study. Occasionally proximal stratigraphies may be unrepresentative of the complete eruptive history because of a lack of exposure due to burial by more recent effusive and explosive activity, or sector collapse which can remove vital stratigraphy particularly on volcanic islands.
    Description: Published
    Description: 74-94
    Description: JCR Journal
    Description: restricted
    Keywords: Marsili Basin ; Glass chemistry ; Tephra ; Trace element ; Aeolian Islands ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 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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  • 9
    Publication Date: 2021-12-06
    Description: Marked changes in human dispersal and development during the Middle to Upper Paleolithic transition have been attributed to massive volcanic eruption and/or severe climatic deterioration. We test this concept using records of volcanic ash layers of the Campanian Ignimbrite eruption dated to ca. 40,000 y ago (40 ka B.P.). The distribution of the Campanian Ignimbrite has been enhanced by the discovery of cryptotephra deposits (volcanic ash layers that are not visible to the naked eye) in archaeological cave sequences. They enable us to synchronize archaeological and paleoclimatic records through the period of transition from Neanderthal to the earliest anatomically modern human populations in Europe. Our results con!rm that the combined effects of a major volcanic eruption and severe climatic cooling failed to have lasting impacts on Neanderthals or early modern humans in Europe. We infer that modern humans proved a greater competitive threat to indigenous populations than natural disasters.
    Description: funded by the United Kingdom Natural Environment Research Council through a Response of Humans to Abrupt Environmental Transitions (RESET) Consortium Grant
    Description: Published
    Description: 13532–13537
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: JCR Journal
    Description: restricted
    Keywords: Neanderthals ; modern humans ; cryptotephra deposits ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 10
    Publication Date: 2010-03-19
    Print ISSN: 0031-9007
    Electronic ISSN: 1079-7114
    Topics: Physics
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