Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts
The study of silicon (Si) isotopes in Ocean Island Basalts (OIB) has the potential to discern between different models for the origins of geochemical heterogeneities in the mantle. Relatively large (∼several per mil per atomic mass unit) Si isotope fractionation occurs in low-temperature environment...
Published in: | Geochimica et Cosmochimica Acta |
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2016
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Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/silicon-isotopes-reveal-recycled-altered-oceanic-crust-in-the-mantle-sources-of-ocean-island-basalts(3a93d1be-ec62-4994-99ab-3db7061145af).html https://doi.org/10.1016/j.gca.2016.06.008 https://research-repository.st-andrews.ac.uk/bitstream/10023/10979/1/Savage_2016_GCA_Basalts_AAM.pdf |
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/3a93d1be-ec62-4994-99ab-3db7061145af 2023-05-15T16:52:23+02:00 Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts Pringle, Emily A. Moynier, Frédéric Savage, Paul S. Jackson, Matthew G. Moreira, Manuel Day, James M.D. 2016-09-15 application/pdf https://risweb.st-andrews.ac.uk/portal/en/researchoutput/silicon-isotopes-reveal-recycled-altered-oceanic-crust-in-the-mantle-sources-of-ocean-island-basalts(3a93d1be-ec62-4994-99ab-3db7061145af).html https://doi.org/10.1016/j.gca.2016.06.008 https://research-repository.st-andrews.ac.uk/bitstream/10023/10979/1/Savage_2016_GCA_Basalts_AAM.pdf eng eng info:eu-repo/semantics/openAccess Pringle , E A , Moynier , F , Savage , P S , Jackson , M G , Moreira , M & Day , J M D 2016 , ' Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts ' , Geochimica et Cosmochimica Acta , vol. 189 , pp. 282-295 . https://doi.org/10.1016/j.gca.2016.06.008 Silicon isotopes Ocean Island Basalts Mantle heterogeneity Recycling article 2016 ftunstandrewcris https://doi.org/10.1016/j.gca.2016.06.008 2022-06-02T07:46:12Z The study of silicon (Si) isotopes in Ocean Island Basalts (OIB) has the potential to discern between different models for the origins of geochemical heterogeneities in the mantle. Relatively large (∼several per mil per atomic mass unit) Si isotope fractionation occurs in low-temperature environments during biochemical and geochemical precipitation of dissolved Si, where the precipitate is preferentially enriched in the lighter isotopes relative to the dissolved Si. In contrast, only a limited range (∼tenths of a per mil) of Si isotope fractionation has been observed from high-temperature igneous processes. Therefore, Si isotopes may be useful as tracers for the presence of crustal material within OIB mantle source regions that experienced relatively low-temperature surface processes in a manner similar to other stable isotope systems, such as oxygen. Characterizing the isotopic composition of the mantle is also of central importance to the use of the Si isotope system as a basis for comparisons with other planetary bodies (e.g., Moon, Mars, asteroids). Here we present the first comprehensive suite of high-precision Si isotope data obtained by MC-ICP-MS for a diverse suite of OIB. Samples originate from ocean islands in the Pacific, Atlantic, and Indian Ocean basins and include representative end-members for the EM-1, EM-2, and HIMU mantle components. On average, δ 30 Si values for OIB (−0.32 ± 0.09‰, 2 sd) are in general agreement with previous estimates for the δ 30 Si value of Bulk Silicate Earth (−0.29 ± 0.07‰, 2 sd; Savage et al., 2014). Nonetheless, some small systematic variations are present; specifically, most HIMU-type (Mangaia; Cape Verde; La Palma, Canary Islands) and Iceland OIB are enriched in the lighter isotopes of Si (δ 30 Si values lower than MORB), consistent with recycled altered oceanic crust and lithospheric mantle in their mantle sources. Article in Journal/Newspaper Iceland Ocean Island University of St Andrews: Research Portal Indian Pacific Geochimica et Cosmochimica Acta 189 282 295 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
Silicon isotopes Ocean Island Basalts Mantle heterogeneity Recycling |
spellingShingle |
Silicon isotopes Ocean Island Basalts Mantle heterogeneity Recycling Pringle, Emily A. Moynier, Frédéric Savage, Paul S. Jackson, Matthew G. Moreira, Manuel Day, James M.D. Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts |
topic_facet |
Silicon isotopes Ocean Island Basalts Mantle heterogeneity Recycling |
description |
The study of silicon (Si) isotopes in Ocean Island Basalts (OIB) has the potential to discern between different models for the origins of geochemical heterogeneities in the mantle. Relatively large (∼several per mil per atomic mass unit) Si isotope fractionation occurs in low-temperature environments during biochemical and geochemical precipitation of dissolved Si, where the precipitate is preferentially enriched in the lighter isotopes relative to the dissolved Si. In contrast, only a limited range (∼tenths of a per mil) of Si isotope fractionation has been observed from high-temperature igneous processes. Therefore, Si isotopes may be useful as tracers for the presence of crustal material within OIB mantle source regions that experienced relatively low-temperature surface processes in a manner similar to other stable isotope systems, such as oxygen. Characterizing the isotopic composition of the mantle is also of central importance to the use of the Si isotope system as a basis for comparisons with other planetary bodies (e.g., Moon, Mars, asteroids). Here we present the first comprehensive suite of high-precision Si isotope data obtained by MC-ICP-MS for a diverse suite of OIB. Samples originate from ocean islands in the Pacific, Atlantic, and Indian Ocean basins and include representative end-members for the EM-1, EM-2, and HIMU mantle components. On average, δ 30 Si values for OIB (−0.32 ± 0.09‰, 2 sd) are in general agreement with previous estimates for the δ 30 Si value of Bulk Silicate Earth (−0.29 ± 0.07‰, 2 sd; Savage et al., 2014). Nonetheless, some small systematic variations are present; specifically, most HIMU-type (Mangaia; Cape Verde; La Palma, Canary Islands) and Iceland OIB are enriched in the lighter isotopes of Si (δ 30 Si values lower than MORB), consistent with recycled altered oceanic crust and lithospheric mantle in their mantle sources. |
format |
Article in Journal/Newspaper |
author |
Pringle, Emily A. Moynier, Frédéric Savage, Paul S. Jackson, Matthew G. Moreira, Manuel Day, James M.D. |
author_facet |
Pringle, Emily A. Moynier, Frédéric Savage, Paul S. Jackson, Matthew G. Moreira, Manuel Day, James M.D. |
author_sort |
Pringle, Emily A. |
title |
Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts |
title_short |
Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts |
title_full |
Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts |
title_fullStr |
Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts |
title_full_unstemmed |
Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts |
title_sort |
silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts |
publishDate |
2016 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/silicon-isotopes-reveal-recycled-altered-oceanic-crust-in-the-mantle-sources-of-ocean-island-basalts(3a93d1be-ec62-4994-99ab-3db7061145af).html https://doi.org/10.1016/j.gca.2016.06.008 https://research-repository.st-andrews.ac.uk/bitstream/10023/10979/1/Savage_2016_GCA_Basalts_AAM.pdf |
geographic |
Indian Pacific |
geographic_facet |
Indian Pacific |
genre |
Iceland Ocean Island |
genre_facet |
Iceland Ocean Island |
op_source |
Pringle , E A , Moynier , F , Savage , P S , Jackson , M G , Moreira , M & Day , J M D 2016 , ' Silicon isotopes reveal recycled altered oceanic crust in the mantle sources of ocean island basalts ' , Geochimica et Cosmochimica Acta , vol. 189 , pp. 282-295 . https://doi.org/10.1016/j.gca.2016.06.008 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.gca.2016.06.008 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
189 |
container_start_page |
282 |
op_container_end_page |
295 |
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1766042579598573568 |