Upper Pleistocene tephra layer from Pantelleria at the island of Lampedusa (Sicily Channel, Central Mediterranean)

Mara Galletti, Biancamaria Narcisi

Research output: Contribution to journalArticle

Abstract

A thin (1.5 cm) air-fall tephra layer has been identified in an Upper Pleistocene sedimentary sequence outcropping in the eastern part of Lampedusa Island (35°30°N, 12°40' E; Sicily Channel). It is embedded into continental deposits resting unconformably upon marine sediments related to the Eutyrrhenian transgression (marine oxygen isotope substage 5e, ca. 125 ka). Under the microscope, the tephra layer displays characteristic spherical hollow shards, which are accompanied by pumice pyroclasts and thin fragments of vesicle walls. From the chemical point of view, it can be classified as rhyolite, with distinctive peralkaline composition and low Al/Fe ratio. Both micro-morphological and chemical features indicate that the tephra originated from the Pantelleria volcano, located some 150 km NNW of Lampedusa. In particular, a relation is suggested with the explosive activity of Pantelleria occurred before the emplacement of the Green Tuff (50 ka). Given its peculiar features, this tephra layer may represent a valuable marker for late Pleistocene stratigraphic studies in the Central Mediterranean, at least in the Sicily Channel and adjacent continental regions. Its finding at Lampedusa contributes to knowledge of ash distribution of Pantelleria explosive events and provides constraints on the age of the sedimentary sequence embedding the tephra layer.
Original languageEnglish
Pages (from-to)201 - 208
Number of pages8
JournalGeoActa
Volume2
Publication statusPublished - 2003
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Geology

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