New tephrostratigraphic data from three marine cores sampled in different depositional settings around southern Italy's coastline allowed correlating each of them with the regional tephrostratigraphy and to gain insights on ash dispersal from explosive eruptions of various intensities. Volume magnetic susceptibility curves, lithological analysis and geochemistry allowed the recognition of 38 tephras or cryptotephras in the three cores. The lithology of each tephra/cryptotephra was described, and the major element composition of volcanic glasses determined. Major element compositions of mineral phases and trace element compositions of bulk rock and volcanic glasses were also determined for selected samples. The majority of tephras/cryptotephras were correlated with the activity of Neapolitan volcanoes (16 from Somma-Vesuvius, 13 from Campi Flegrei, 1 from Ischia Island), whereas the others were correlated with deposits from to the volcanic activity of Lipari Island (6) and Mount Etna (1). The different tephras/cryptotephras were correlated to nine Plinian/Subplinian eruptions that occurred in the central Mediterranean region in the last 15,000 years. In addition, correlation with proximal counterparts highlighted the occurrence in marine core successions of several tephra layers related with moderately explosive eruptions from Neapolitan volcanoes that, in some cases, show dispersal areas comparable to those of Subplinian products. This finding means that the amount of fine-grained particles produced during explosive eruptions is independent with respect to the intensity of the eruption itself.
On ash dispersal from moderately explosive volcanic eruptions: Examples from Holocene and Late Pleistocene eruptions of Italian volcanoes
Crocitti, M.;Sulpizio, R.;De Rosa, R.;Donato, P.;IORIO, MARIAFRANCESCA;Barca, D.;Lubritto, C.
2019-01-01
Abstract
New tephrostratigraphic data from three marine cores sampled in different depositional settings around southern Italy's coastline allowed correlating each of them with the regional tephrostratigraphy and to gain insights on ash dispersal from explosive eruptions of various intensities. Volume magnetic susceptibility curves, lithological analysis and geochemistry allowed the recognition of 38 tephras or cryptotephras in the three cores. The lithology of each tephra/cryptotephra was described, and the major element composition of volcanic glasses determined. Major element compositions of mineral phases and trace element compositions of bulk rock and volcanic glasses were also determined for selected samples. The majority of tephras/cryptotephras were correlated with the activity of Neapolitan volcanoes (16 from Somma-Vesuvius, 13 from Campi Flegrei, 1 from Ischia Island), whereas the others were correlated with deposits from to the volcanic activity of Lipari Island (6) and Mount Etna (1). The different tephras/cryptotephras were correlated to nine Plinian/Subplinian eruptions that occurred in the central Mediterranean region in the last 15,000 years. In addition, correlation with proximal counterparts highlighted the occurrence in marine core successions of several tephra layers related with moderately explosive eruptions from Neapolitan volcanoes that, in some cases, show dispersal areas comparable to those of Subplinian products. This finding means that the amount of fine-grained particles produced during explosive eruptions is independent with respect to the intensity of the eruption itself.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
