Cooper, CL, Savov, IP and Swindles, GT orcid.org/0000-0001-8039-1790 (2019) Standard chemical‐based tephra extraction methods significantly alter the geochemistry of volcanic glass shards. Journal of Quaternary Science, 34 (8). pp. 697-707. ISSN 0267-8179
Abstract
The chemical compositions of tephra shards are widely utilised in a myriad of disciplines, including volcanology, petrology, tephrochronology, palaeoecology and climate studies. Previous research has raised concerns over the possible chemical alteration of microscopic (<100 µm) volcanic glass shards through standard extraction procedures, such as the widely used acid digestion method. This study subjects 10 samples of well‐characterised volcanic glasses ranging from basalt to rhyolite to three common methods used in the extraction of volcanic material from lake sediments and peats. The major element geochemistry of each sample was analysed and compared with a control group. The results of this test indicate that basaltic and andesitic glasses are highly susceptible to chemical alteration, particularly to the concentrated corrosive materials used in acid and base digestion techniques. PERMANOVA analysis of the variation within groups suggests that the oxides most susceptible to variation are alkalis from groups I and II (K2O, Na2O, CaO, MgO) and SiO2, and the most stable oxides are Al2O3 and FeO. Felsic glasses are considerably less susceptible to alteration by both acidic (HCl, HNO3, H2SO4) and alkaline (KOH) digestions. Our findings have important implications for interpreting the geochemistry of volcanic glasses.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 John Wiley & Sons, Ltd. This is the peer reviewed version of the following article: Cooper, C.L., Savov, I.P. and Swindles, G.T. (2019), Standard chemical‐based tephra extraction methods significantly alter the geochemistry of volcanic glass shards. J. Quaternary Sci, 34: 697-707. doi:10.1002/jqs.3169, which has been published in final form at https://doi.org/10.1002/jqs.3169. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | basaltic; EPMA; experimental methods; glass preservation; tephrochronology |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Geography (Leeds) > Ecology & Global Change (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 11 Dec 2019 11:09 |
Last Modified: | 28 Nov 2020 01:51 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/jqs.3169 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:154475 |