Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting
Glacial modulation of melting beneath Iceland provides a unique opportunity to better understand both the nature and length scale of mantle heterogeneity. At the end of the last glacial period, View the MathML source BP, eruption rates were ∼20–100 times greater than in glacial or late postglacial t...
id |
ftucambridgeesc:oai:eprints.esc.cam.ac.uk:2891 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
University of Cambridge, Department of Earth Sciences: ESC Publications |
op_collection_id |
ftucambridgeesc |
language |
English |
topic |
02 - Geodynamics Geophysics and Tectonics |
spellingShingle |
02 - Geodynamics Geophysics and Tectonics Sims, Kenneth W.W. Maclennan, John Blichert-Toft, Janne Mervine, Evelyn M. Blusztajn, Jurek Grönvold, Karl Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting |
topic_facet |
02 - Geodynamics Geophysics and Tectonics |
description |
Glacial modulation of melting beneath Iceland provides a unique opportunity to better understand both the nature and length scale of mantle heterogeneity. At the end of the last glacial period, View the MathML source BP, eruption rates were ∼20–100 times greater than in glacial or late postglacial times and geophysical modeling posits that rapid melting of the large ice sheet covering Iceland caused a transient increase in mantle decompression melting rates. Here we present the first time-series of Sr–Nd–Hf–Pb isotopic data for a full glacial cycle from a spatially confined region of basaltic volcanism in northern Iceland. Basalts and picrites erupted during the early postglacial burst of volcanic activity are systematically offset to more depleted isotopic compositions than those of lavas erupted during glacial or recent (<7 kyr) times. These new isotopic data, coupled with major and trace element data, show that the mantle underneath northern Iceland is heterogeneous on small (<100 km) length scales. The temporal response of the isotopic compositions of the basalts to glacial unloading indicates that the isotopic composition of mantle heterogeneities can be linked to their melting behavior. The present geochemical data can be accounted for by a melting model in which a lithologically heterogeneous mantle source contains an enriched component more fusible than its companion depleted component. |
format |
Article in Journal/Newspaper |
author |
Sims, Kenneth W.W. Maclennan, John Blichert-Toft, Janne Mervine, Evelyn M. Blusztajn, Jurek Grönvold, Karl |
author_facet |
Sims, Kenneth W.W. Maclennan, John Blichert-Toft, Janne Mervine, Evelyn M. Blusztajn, Jurek Grönvold, Karl |
author_sort |
Sims, Kenneth W.W. |
title |
Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting |
title_short |
Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting |
title_full |
Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting |
title_fullStr |
Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting |
title_full_unstemmed |
Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting |
title_sort |
short length scale mantle heterogeneity beneath iceland probed by glacial modulation of melting |
publishDate |
2013 |
url |
http://eprints.esc.cam.ac.uk/2891/ http://eprints.esc.cam.ac.uk/2891/1/Sims%20et%20al.%20-%202013%20-%20Short%20length%20scale%20mantle%20heterogeneity%20beneath%20Ic.pdf http://eprints.esc.cam.ac.uk/2891/2/JMAC%201-s2.0-S0012821X13004020-gr001.sml.gif http://eprints.esc.cam.ac.uk/2891/3/sup1-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/4/sup3-s2.0-S0012821X13004020-mmc3.jpg http://eprints.esc.cam.ac.uk/2891/5/sup4-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/6/sup5-s2.0-S0012821X13004020-mmc5.jpg http://eprints.esc.cam.ac.uk/2891/7/sup6-s2.0-S0012821X13004020-mmc6.jpg http://eprints.esc.cam.ac.uk/2891/8/SUP2-s2.0-S0012821X13004020-mmc2.jpg http://eprints.esc.cam.ac.uk/2891/9/mmc7.pdf http://eprints.esc.cam.ac.uk/2891/10/mmc8.pdf http://eprints.esc.cam.ac.uk/2891/11/mmc9.pdf http://eprints.esc.cam.ac.uk/2891/12/mmc10.pdf http://eprints.esc.cam.ac.uk/2891/13/mmc11.docx http://www.sciencedirect.com/science/article/pii/S0012821X13004020 |
genre |
Ice Sheet Iceland |
genre_facet |
Ice Sheet Iceland |
op_relation |
http://eprints.esc.cam.ac.uk/2891/1/Sims%20et%20al.%20-%202013%20-%20Short%20length%20scale%20mantle%20heterogeneity%20beneath%20Ic.pdf http://eprints.esc.cam.ac.uk/2891/2/JMAC%201-s2.0-S0012821X13004020-gr001.sml.gif http://eprints.esc.cam.ac.uk/2891/3/sup1-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/4/sup3-s2.0-S0012821X13004020-mmc3.jpg http://eprints.esc.cam.ac.uk/2891/5/sup4-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/6/sup5-s2.0-S0012821X13004020-mmc5.jpg http://eprints.esc.cam.ac.uk/2891/7/sup6-s2.0-S0012821X13004020-mmc6.jpg http://eprints.esc.cam.ac.uk/2891/8/SUP2-s2.0-S0012821X13004020-mmc2.jpg http://eprints.esc.cam.ac.uk/2891/9/mmc7.pdf http://eprints.esc.cam.ac.uk/2891/10/mmc8.pdf http://eprints.esc.cam.ac.uk/2891/11/mmc9.pdf http://eprints.esc.cam.ac.uk/2891/12/mmc10.pdf http://eprints.esc.cam.ac.uk/2891/13/mmc11.docx Sims, Kenneth W.W. and Maclennan, John and Blichert-Toft, Janne and Mervine, Evelyn M. and Blusztajn, Jurek and Grönvold, Karl (2013) Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting. Earth and Planetary Science Letters, 379. pp. 146-157. ISSN 0012-821X |
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1766031575976247296 |
spelling |
ftucambridgeesc:oai:eprints.esc.cam.ac.uk:2891 2023-05-15T16:41:08+02:00 Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting Sims, Kenneth W.W. Maclennan, John Blichert-Toft, Janne Mervine, Evelyn M. Blusztajn, Jurek Grönvold, Karl 2013-10 text image http://eprints.esc.cam.ac.uk/2891/ http://eprints.esc.cam.ac.uk/2891/1/Sims%20et%20al.%20-%202013%20-%20Short%20length%20scale%20mantle%20heterogeneity%20beneath%20Ic.pdf http://eprints.esc.cam.ac.uk/2891/2/JMAC%201-s2.0-S0012821X13004020-gr001.sml.gif http://eprints.esc.cam.ac.uk/2891/3/sup1-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/4/sup3-s2.0-S0012821X13004020-mmc3.jpg http://eprints.esc.cam.ac.uk/2891/5/sup4-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/6/sup5-s2.0-S0012821X13004020-mmc5.jpg http://eprints.esc.cam.ac.uk/2891/7/sup6-s2.0-S0012821X13004020-mmc6.jpg http://eprints.esc.cam.ac.uk/2891/8/SUP2-s2.0-S0012821X13004020-mmc2.jpg http://eprints.esc.cam.ac.uk/2891/9/mmc7.pdf http://eprints.esc.cam.ac.uk/2891/10/mmc8.pdf http://eprints.esc.cam.ac.uk/2891/11/mmc9.pdf http://eprints.esc.cam.ac.uk/2891/12/mmc10.pdf http://eprints.esc.cam.ac.uk/2891/13/mmc11.docx http://www.sciencedirect.com/science/article/pii/S0012821X13004020 en eng http://eprints.esc.cam.ac.uk/2891/1/Sims%20et%20al.%20-%202013%20-%20Short%20length%20scale%20mantle%20heterogeneity%20beneath%20Ic.pdf http://eprints.esc.cam.ac.uk/2891/2/JMAC%201-s2.0-S0012821X13004020-gr001.sml.gif http://eprints.esc.cam.ac.uk/2891/3/sup1-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/4/sup3-s2.0-S0012821X13004020-mmc3.jpg http://eprints.esc.cam.ac.uk/2891/5/sup4-s2.0-S0012821X13004020-mmc1.jpg http://eprints.esc.cam.ac.uk/2891/6/sup5-s2.0-S0012821X13004020-mmc5.jpg http://eprints.esc.cam.ac.uk/2891/7/sup6-s2.0-S0012821X13004020-mmc6.jpg http://eprints.esc.cam.ac.uk/2891/8/SUP2-s2.0-S0012821X13004020-mmc2.jpg http://eprints.esc.cam.ac.uk/2891/9/mmc7.pdf http://eprints.esc.cam.ac.uk/2891/10/mmc8.pdf http://eprints.esc.cam.ac.uk/2891/11/mmc9.pdf http://eprints.esc.cam.ac.uk/2891/12/mmc10.pdf http://eprints.esc.cam.ac.uk/2891/13/mmc11.docx Sims, Kenneth W.W. and Maclennan, John and Blichert-Toft, Janne and Mervine, Evelyn M. and Blusztajn, Jurek and Grönvold, Karl (2013) Short length scale mantle heterogeneity beneath Iceland probed by glacial modulation of melting. Earth and Planetary Science Letters, 379. pp. 146-157. ISSN 0012-821X 02 - Geodynamics Geophysics and Tectonics Article PeerReviewed 2013 ftucambridgeesc 2020-08-27T18:09:27Z Glacial modulation of melting beneath Iceland provides a unique opportunity to better understand both the nature and length scale of mantle heterogeneity. At the end of the last glacial period, View the MathML source BP, eruption rates were ∼20–100 times greater than in glacial or late postglacial times and geophysical modeling posits that rapid melting of the large ice sheet covering Iceland caused a transient increase in mantle decompression melting rates. Here we present the first time-series of Sr–Nd–Hf–Pb isotopic data for a full glacial cycle from a spatially confined region of basaltic volcanism in northern Iceland. Basalts and picrites erupted during the early postglacial burst of volcanic activity are systematically offset to more depleted isotopic compositions than those of lavas erupted during glacial or recent (<7 kyr) times. These new isotopic data, coupled with major and trace element data, show that the mantle underneath northern Iceland is heterogeneous on small (<100 km) length scales. The temporal response of the isotopic compositions of the basalts to glacial unloading indicates that the isotopic composition of mantle heterogeneities can be linked to their melting behavior. The present geochemical data can be accounted for by a melting model in which a lithologically heterogeneous mantle source contains an enriched component more fusible than its companion depleted component. Article in Journal/Newspaper Ice Sheet Iceland University of Cambridge, Department of Earth Sciences: ESC Publications |