The major and trace element glass compositions of the productive Mediterranean volcanic sources: tools for correlating distal tephra layers in and around Europe

Tomlinson, Emma L.; Smith, Victoria C.; Albert, Paul G.; Aydar, Erkan; Civetta, Lucia; Cioni, Raffaello; Çubukçu, Evren; Gertisser, Ralf; Isaia, Roberto; Menzies, Martin A.; Orsi, Giovanni; Rosi, Mauro; Zanchetta, Giovanni

Abstract

The increasing application of cryptotephra studies is leading the identification of new tephra marker layers the sources of which in many cases may not be known or may be ambiguous. In this contribution, we discuss the controls on tephra geochemistry in the context of establishing the provenance of an unknown tephra layer. We use the RESET database (https://c14.arch.ox.ac.uk), which contains major and trace element data for a number of European silicic tephra erupted in the period 100 ka to ca 10 ka, to define new and modify existing tectonic setting discrimination diagrams for use with volcanic glass analyses. Bivariate plots of the elements Rb, Nb, Ta, Y and Th and K2O, SiO2, FeO and MgO can be used to identify tephra from different tectonic settings. New, detailed glass chemistry shows that tephra from the productive Neapolitan volcanic centres, Somma-Vesuvius (22–4 ka activity), Campi Flegrei (60–15 ka) and Ischia (75–20 ka), can be separated using major elements, CaO–SiO2, Na2O/K2O–CaO and CaO–MgO. In each of these centres, the tephrostratigraphic record is characterized by the repeated occurrence of similar glass compositions, punctuated by significant changes in magma chemistry. The glass compositions of successive eruptions from Campi Flegrei are similar but there is a significant change in the composition following the Campanian Ignimbrite, and there are comparable compositional changes at Ischia following the Monte Epomeo Green Tuff eruption and at Somma-Vesuvius following the Verdoline event. Distinguishing different tephras from a single volcanic centre is more problematic, and in some instances even impossible, without good chronological and stratigraphic control and/or high-resolution trace element glass data. At Somma-Vesuvius certain major elements can be used to separate glasses from the major chronological phases (Group 1 – Pomici di Base and Verdoline; Group 2 – Mercato and Avellino), but separating tephras within a single group on the basis of glass composition can be problematic.

Citation

Tomlinson, E. L., Smith, V. C., Albert, P. G., Aydar, E., Civetta, L., Cioni, R., …Zanchetta, G. (2015). The major and trace element glass compositions of the productive Mediterranean volcanic sources: tools for correlating distal tephra layers in and around Europe. Quaternary Science Reviews, 118, 48-66. https://doi.org/10.1016/j.quascirev.2014.10.028

• Journal Article Type: Article
• Acceptance Date: Oct 28, 2014
• Online Publication Date: Nov 29, 2014
• Publication Date: 2015-06
• Deposit Date: May 30, 2023
• Journal: Quaternary Science Reviews
• Print ISSN: 0277-3791
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 118
• Pages: 48-66
• DOI: https://doi.org/10.1016/j.quascirev.2014.10.028
• Keywords: Geology; Archeology; Archeology; Ecology, Evolution, Behavior and Systematics; Global and Planetary Change
• Additional Information: This article is maintained by: Elsevier; Article Title: The major and trace element glass compositions of the productive Mediterranean volcanic sources: tools for correlating distal tephra layers in and around Europe; Journal Title: Quaternary Science Reviews; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.quascirev.2014.10.028; Content Type: article; Copyright: Copyright © 2014 Elsevier Ltd. All rights reserved.