Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5783859 | Journal of Volcanology and Geothermal Research | 2017 | 84 Pages |
Abstract
Volcanic ash (<Â 2Â mm) erupted from the Aeolian Islands is reported distally as layers in sedimentary archives from across the central Mediterranean region. Here we present volcanic glass geochemistry of proximal tephra deposits from explosive eruptions on the islands of Vulcano, Lipari, Salina and Stromboli spanning approximately the last 50Â ka using grain-specific EMPA and LA-ICP-MS. This comprehensive database of volcanic glass compositions (>Â 1000 analyses) provides a basis for proximal-distal and distal-distal tephra correlations. Tephra deposits from the different Aeolian Islands are geochemically diverse; with some individual eruptions showing diagnostic geochemical heterogeneity recognised both stratigraphically and/or spatially. Major element glass analyses reveal that Vulcano (0-21Â ka) and Stromboli (4-13Â ka) have erupted potassic (shoshonitic and K-series) tephra with broadly overlapping compositions, but data presented here demonstrates that their eruptive products can be distinguished using either TiO2 contents or their HFSE/Th ratios. Whilst individual volcanic sources often produce successive tephra deposits with near identical major and minor element compositions through time (i.e., Lipari, Vulcano), trace element glass data can help to decipher successive eruptions. Changes in LREE and Th concentrations of volcanic glasses erupted spanning approximately the last 50Â ka greatly enhance the potential to discriminate successive eruptive units on Lipari. The new proximal glass database has been used to verify new (Ionian Sea; core M25/4-12) and existing distal occurrences of Aeolian Island derived tephra enabling the reassessments of past ash dispersals. Finally, proximal and distal data have been used to establish an integrated proximal-distal eruptive event stratigraphy for the Aeolian Islands.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geochemistry and Petrology
Authors
Paul G Albert, Emma L Tomlinson, Victoria C Smith, Federico Di Traglia, Marco Pistolesi, Anna Morris, Paola Donato, Rosanna De Rosa, Roberto Sulpizio, Jörg Keller, Mauro Rosi, Martin Menzies,