Journal article
Historic magmatism on the Reykjanes Peninsula, Iceland: a snap-shot of melt generation at a ridge segment
Contributions to Mineralogy and Petrology, Vol.157(3), pp.359-382
03/2009
DOI: 10.1007/s00410-008-0339-4
Abstract
We present new compositional data on a suite of historic lava flows from the Reykjanes Peninsula, Iceland. They were erupted over a short time period between c. 940 and c. 1340 ad and provide a snap-shot view of melt generation and evolution processes beneath this onshore, 65 km long, ridge segment. The lavas are tholeiitic basalts (MgO 6.5–9.2 wt%) and sparsely (≪5%) olivine and/or plagioclase phyric (±trace clinopyroxene). Individual eruptive events show remarkable compositional homogeneity. Despite a limited variation in Sr–Nd isotope compositions, high-precision double-spike Pb isotope data show tight coherent arrays that, together with correlations with incompatible trace element ratios, indicate control by binary mixing processes. Poor correlations with elemental abundances require that this mixing took place prior to extensive fractional crystallisation. Olivines in the historic lavas have light δ18O values (+4.2 to +4.3‰), which is likely to be a feature of the enriched mantle source to Reykjanes Peninsula lavas. High precision Pb isotope analyses of other post-glacial Reykjanes Peninsula lavas show significant variability in 207Pb/204Pb and 208Pb/204Pb at lower 206Pb/204Pb values than in the historic lavas. This variation demonstrates that at least three compositionally distinct components within the mantle are required to explain the Pb isotope variations within the Reykjanes Peninsula as a whole.
Details
- Title: Subtitle
- Historic magmatism on the Reykjanes Peninsula, Iceland: a snap-shot of melt generation at a ridge segment
- Creators
- David Peate - Department of Geoscience University of Iowa 121 Trowbridge Hall Iowa City IA 52242 USAJoel Baker - School of Geography, Environmental and Earth Sciences Victoria University of Wellington P.O. Box 600 Wellington New ZealandSveinn Jakobsson - Icelandic Institute of Natural History Hlemmur 3 105 Reykjavik IcelandTod Waight - Geological Institute University of Copenhagen Øster Voldgade 10 1350 Copenhagen K DenmarkAdam Kent - Department of Geosciences Oregon State University 104 Wilkinson Hall Corvallis OR 97330 USANathalie Grassineau - Department of Geology Royal Holloway University of London Egham, Surrey TW20 0EX UKAnna Skovgaard - Danish Environmental Protection Agency 1401 Copenhagen Denmark
- Resource Type
- Journal article
- Publication Details
- Contributions to Mineralogy and Petrology, Vol.157(3), pp.359-382
- Publisher
- Springer-Verlag; Berlin/Heidelberg
- DOI
- 10.1007/s00410-008-0339-4
- ISSN
- 0010-7999
- eISSN
- 1432-0967
- Language
- English
- Date published
- 03/2009
- Academic Unit
- Earth and Environmental Sciences; Honors Program
- Record Identifier
- 9983983661402771
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