Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle
Stable barium (Ba) isotopes are emerging as tracers for the recycling of crustal material into the mantle. Small but significant Ba isotope variations have been found in global MORB (δ 138/134 Ba values of −0.04‰ to 0.15‰), but the processes causing these Ba isotope variations remain poorly understo...
Published in: | Geochimica et Cosmochimica Acta |
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Language: | English |
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2023
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Online Access: | https://researchers.mq.edu.au/en/publications/64b02e24-5b52-4ee0-bf50-4b0f3788ed76 https://doi.org/10.1016/j.gca.2022.11.013 http://www.scopus.com/inward/record.url?scp=85142315294&partnerID=8YFLogxK |
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ftmacquarieunicr:oai:https://researchers.mq.edu.au:publications/64b02e24-5b52-4ee0-bf50-4b0f3788ed76 2024-06-23T07:56:48+00:00 Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle Wu, Fei Turner, Simon Hoernle, Kaj Hauff, Folkmar Schaefer, Bruce F. Kokfelt, Thomas Bindeman, Ilya 2023-01-01 https://researchers.mq.edu.au/en/publications/64b02e24-5b52-4ee0-bf50-4b0f3788ed76 https://doi.org/10.1016/j.gca.2022.11.013 http://www.scopus.com/inward/record.url?scp=85142315294&partnerID=8YFLogxK eng eng info:eu-repo/semantics/closedAccess Wu , F , Turner , S , Hoernle , K , Hauff , F , Schaefer , B F , Kokfelt , T & Bindeman , I 2023 , ' Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle ' , Geochimica et Cosmochimica Acta , vol. 340 , pp. 85-98 . https://doi.org/10.1016/j.gca.2022.11.013 Ba isotope Depleted upper mantle Mantle heterogeneity Mid-ocean-ridge basalt South Atlantic Ocean article 2023 ftmacquarieunicr https://doi.org/10.1016/j.gca.2022.11.013 2024-06-12T23:47:26Z Stable barium (Ba) isotopes are emerging as tracers for the recycling of crustal material into the mantle. Small but significant Ba isotope variations have been found in global MORB (δ 138/134 Ba values of −0.04‰ to 0.15‰), but the processes causing these Ba isotope variations remain poorly understood. In addition, uncertainties still exist in the estimate of the Ba isotope composition of the depleted upper mantle. Here, we present a systematic study of Ba isotopes for well-characterized MORB glass samples from the South Mid-Atlantic Ridge (SMAR) between 5 and 11°S, which span a wide range of radiogenic isotope ratios and trace element contents. Our results show that the northernmost segment A0 basalts with highly depleted radiogenic isotope compositions have δ 138/134 Ba values ranging from −0.02 to 0.05‰. In comparison, the δ 138/134 Ba values of the isotopically enriched basalts from the A1-A4 segments vary from 0.02 to 0.11‰. Thus, while small, the enriched components involved can be observed to modify the Ba isotope composition of the mantle source beneath A1-A4 segments. Combining our new measurements with literature data, this study places new constraints on the Ba isotope composition of the depleted upper mantle, as well as the origin of Ba isotope heterogeneity in MORB. The Ba isotope composition of the depleted upper mantle in the absence of recycled components is estimated to have a δ 138/134 Ba value of 0.03 to 0.05‰, which can be adopted as the baseline for using Ba isotope ratios as a tracer of mass transfer processes between the crust and mantle. In comparison, global MORB have δ 138/134 Ba values ranging from −0.04‰ to 0.15‰. No global correlation is observed between Ba isotope ratios and geochemical parameters that record mantle enrichment, indicating that the Ba isotope variations in MORB cannot be simply ascribed to the addition of some single component, such as sediment. Models for melting and mixing between recycled materials and depleted mantle suggest that the variable Ba isotope ... Article in Journal/Newspaper South Atlantic Ocean Macquarie University Research Portal Mid-Atlantic Ridge Geochimica et Cosmochimica Acta 340 85 98 |
institution |
Open Polar |
collection |
Macquarie University Research Portal |
op_collection_id |
ftmacquarieunicr |
language |
English |
topic |
Ba isotope Depleted upper mantle Mantle heterogeneity Mid-ocean-ridge basalt South Atlantic Ocean |
spellingShingle |
Ba isotope Depleted upper mantle Mantle heterogeneity Mid-ocean-ridge basalt South Atlantic Ocean Wu, Fei Turner, Simon Hoernle, Kaj Hauff, Folkmar Schaefer, Bruce F. Kokfelt, Thomas Bindeman, Ilya Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle |
topic_facet |
Ba isotope Depleted upper mantle Mantle heterogeneity Mid-ocean-ridge basalt South Atlantic Ocean |
description |
Stable barium (Ba) isotopes are emerging as tracers for the recycling of crustal material into the mantle. Small but significant Ba isotope variations have been found in global MORB (δ 138/134 Ba values of −0.04‰ to 0.15‰), but the processes causing these Ba isotope variations remain poorly understood. In addition, uncertainties still exist in the estimate of the Ba isotope composition of the depleted upper mantle. Here, we present a systematic study of Ba isotopes for well-characterized MORB glass samples from the South Mid-Atlantic Ridge (SMAR) between 5 and 11°S, which span a wide range of radiogenic isotope ratios and trace element contents. Our results show that the northernmost segment A0 basalts with highly depleted radiogenic isotope compositions have δ 138/134 Ba values ranging from −0.02 to 0.05‰. In comparison, the δ 138/134 Ba values of the isotopically enriched basalts from the A1-A4 segments vary from 0.02 to 0.11‰. Thus, while small, the enriched components involved can be observed to modify the Ba isotope composition of the mantle source beneath A1-A4 segments. Combining our new measurements with literature data, this study places new constraints on the Ba isotope composition of the depleted upper mantle, as well as the origin of Ba isotope heterogeneity in MORB. The Ba isotope composition of the depleted upper mantle in the absence of recycled components is estimated to have a δ 138/134 Ba value of 0.03 to 0.05‰, which can be adopted as the baseline for using Ba isotope ratios as a tracer of mass transfer processes between the crust and mantle. In comparison, global MORB have δ 138/134 Ba values ranging from −0.04‰ to 0.15‰. No global correlation is observed between Ba isotope ratios and geochemical parameters that record mantle enrichment, indicating that the Ba isotope variations in MORB cannot be simply ascribed to the addition of some single component, such as sediment. Models for melting and mixing between recycled materials and depleted mantle suggest that the variable Ba isotope ... |
format |
Article in Journal/Newspaper |
author |
Wu, Fei Turner, Simon Hoernle, Kaj Hauff, Folkmar Schaefer, Bruce F. Kokfelt, Thomas Bindeman, Ilya |
author_facet |
Wu, Fei Turner, Simon Hoernle, Kaj Hauff, Folkmar Schaefer, Bruce F. Kokfelt, Thomas Bindeman, Ilya |
author_sort |
Wu, Fei |
title |
Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle |
title_short |
Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle |
title_full |
Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle |
title_fullStr |
Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle |
title_full_unstemmed |
Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle |
title_sort |
barium isotope composition of depleted morb mantle constrained by basalts from the south mid-atlantic ridge (5–11°s) with implication for recycled components in the convecting upper mantle |
publishDate |
2023 |
url |
https://researchers.mq.edu.au/en/publications/64b02e24-5b52-4ee0-bf50-4b0f3788ed76 https://doi.org/10.1016/j.gca.2022.11.013 http://www.scopus.com/inward/record.url?scp=85142315294&partnerID=8YFLogxK |
geographic |
Mid-Atlantic Ridge |
geographic_facet |
Mid-Atlantic Ridge |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Wu , F , Turner , S , Hoernle , K , Hauff , F , Schaefer , B F , Kokfelt , T & Bindeman , I 2023 , ' Barium isotope composition of depleted MORB mantle constrained by basalts from the South Mid-Atlantic Ridge (5–11°S) with implication for recycled components in the convecting upper mantle ' , Geochimica et Cosmochimica Acta , vol. 340 , pp. 85-98 . https://doi.org/10.1016/j.gca.2022.11.013 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/j.gca.2022.11.013 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
340 |
container_start_page |
85 |
op_container_end_page |
98 |
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1802650138949189632 |