Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation
Whether early Archaean felsic crust was formed by processes related to plate subduction or melting of thick basaltic plateaus is vividly debated. Ultimately, the discussion hinges on the question of how Archaean felsic crust has obtained its distinct chemical traits. Here we report chemical and isot...
Published in: | Earth and Planetary Science Letters |
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ftumanchesterpub:oai:pure.atira.dk:publications/816bb75b-2841-49b8-a247-b6e2726ad048 2023-11-12T04:19:04+01:00 Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation Willbold, Matthias Hegner, Ernst Stracke, Andreas Rocholl, Alexander 2009-03-15 https://research.manchester.ac.uk/en/publications/816bb75b-2841-49b8-a247-b6e2726ad048 https://doi.org/10.1016/j.epsl.2008.12.029 eng eng info:eu-repo/semantics/closedAccess Willbold , M , Hegner , E , Stracke , A & Rocholl , A 2009 , ' Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation ' , Earth and Planetary Science Letters , vol. 279 , no. 1-2 , pp. 44-52 . https://doi.org/10.1016/j.epsl.2008.12.029 Archaean continental crust Iceland oceanic plateau subduction tonalite-trondhjemite-granodiorite (TTG) article 2009 ftumanchesterpub https://doi.org/10.1016/j.epsl.2008.12.029 2023-10-30T09:18:34Z Whether early Archaean felsic crust was formed by processes related to plate subduction or melting of thick basaltic plateaus is vividly debated. Ultimately, the discussion hinges on the question of how Archaean felsic crust has obtained its distinct chemical traits. Here we report chemical and isotopic data for a suite of Cenozoic felsic volcanic rocks from Iceland. The samples exhibit the key-chemical characteristics of early Archaean felsic continental crust such as calc-alkaline composition, strong enrichment in Na relative to K, high Pb/Ce, La/Nb, and Ta/Nb ratios. Involvement of pre-existing continental lithosphere in the petrogenesis of the samples can be excluded, because their 207Pb/204Pb and 206Pb/204Pb ratios plot well within the range of Iceland basalts. Model calculations suggest that the chemical characteristics were produced by high-pressure partial melting of basaltic lower crust followed by fractional crystallisation of amphibole, plagioclase, and ilmenite. These findings demonstrate that plate subduction and melting of subduction-modified mantle or lithosphere are not necessarily required to produce the key-chemical signatures of continental crust. Hence, the calc-alkaline dacites provide intriguing support for early Archaean continental crust formation by melting of thick mafic plateaus. © 2008 Elsevier B.V. All rights reserved. Article in Journal/Newspaper Iceland The University of Manchester: Research Explorer Earth and Planetary Science Letters 279 1-2 44 52 |
institution |
Open Polar |
collection |
The University of Manchester: Research Explorer |
op_collection_id |
ftumanchesterpub |
language |
English |
topic |
Archaean continental crust Iceland oceanic plateau subduction tonalite-trondhjemite-granodiorite (TTG) |
spellingShingle |
Archaean continental crust Iceland oceanic plateau subduction tonalite-trondhjemite-granodiorite (TTG) Willbold, Matthias Hegner, Ernst Stracke, Andreas Rocholl, Alexander Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation |
topic_facet |
Archaean continental crust Iceland oceanic plateau subduction tonalite-trondhjemite-granodiorite (TTG) |
description |
Whether early Archaean felsic crust was formed by processes related to plate subduction or melting of thick basaltic plateaus is vividly debated. Ultimately, the discussion hinges on the question of how Archaean felsic crust has obtained its distinct chemical traits. Here we report chemical and isotopic data for a suite of Cenozoic felsic volcanic rocks from Iceland. The samples exhibit the key-chemical characteristics of early Archaean felsic continental crust such as calc-alkaline composition, strong enrichment in Na relative to K, high Pb/Ce, La/Nb, and Ta/Nb ratios. Involvement of pre-existing continental lithosphere in the petrogenesis of the samples can be excluded, because their 207Pb/204Pb and 206Pb/204Pb ratios plot well within the range of Iceland basalts. Model calculations suggest that the chemical characteristics were produced by high-pressure partial melting of basaltic lower crust followed by fractional crystallisation of amphibole, plagioclase, and ilmenite. These findings demonstrate that plate subduction and melting of subduction-modified mantle or lithosphere are not necessarily required to produce the key-chemical signatures of continental crust. Hence, the calc-alkaline dacites provide intriguing support for early Archaean continental crust formation by melting of thick mafic plateaus. © 2008 Elsevier B.V. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Willbold, Matthias Hegner, Ernst Stracke, Andreas Rocholl, Alexander |
author_facet |
Willbold, Matthias Hegner, Ernst Stracke, Andreas Rocholl, Alexander |
author_sort |
Willbold, Matthias |
title |
Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation |
title_short |
Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation |
title_full |
Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation |
title_fullStr |
Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation |
title_full_unstemmed |
Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation |
title_sort |
continental geochemical signatures in dacites from iceland and implications for models of early archaean crust formation |
publishDate |
2009 |
url |
https://research.manchester.ac.uk/en/publications/816bb75b-2841-49b8-a247-b6e2726ad048 https://doi.org/10.1016/j.epsl.2008.12.029 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Willbold , M , Hegner , E , Stracke , A & Rocholl , A 2009 , ' Continental geochemical signatures in dacites from Iceland and implications for models of early Archaean crust formation ' , Earth and Planetary Science Letters , vol. 279 , no. 1-2 , pp. 44-52 . https://doi.org/10.1016/j.epsl.2008.12.029 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2008.12.029 |
container_title |
Earth and Planetary Science Letters |
container_volume |
279 |
container_issue |
1-2 |
container_start_page |
44 |
op_container_end_page |
52 |
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1782335585834237952 |