Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean
International audience The geochemical characteristics of mildly alkalic basalts (24-25 Ma) erupted in the southeastern Kerguelen Archipelago are considered to represent the best estimate for the composition of the enriched Kerguelen plume end-member. A recent study of picrites and high-MgO basalts...
Published in: | Earth and Planetary Science Letters |
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Main Authors: | , , , , , |
Other Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2006
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Online Access: | https://insu.hal.science/insu-03603221 https://doi.org/10.1016/j.epsl.2005.10.025 |
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ftunivparis:oai:HAL:insu-03603221v1 |
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Université de Paris: Portail HAL |
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language |
English |
topic |
helium and neon isotopes Kerguelen plume high-MgO basalts olivine mantle [SDU]Sciences of the Universe [physics] |
spellingShingle |
helium and neon isotopes Kerguelen plume high-MgO basalts olivine mantle [SDU]Sciences of the Universe [physics] Doucet, Sonia Moreira, Manuel Weis, Dominique Scoates, James S. Giret, André Allègre, Claude Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean |
topic_facet |
helium and neon isotopes Kerguelen plume high-MgO basalts olivine mantle [SDU]Sciences of the Universe [physics] |
description |
International audience The geochemical characteristics of mildly alkalic basalts (24-25 Ma) erupted in the southeastern Kerguelen Archipelago are considered to represent the best estimate for the composition of the enriched Kerguelen plume end-member. A recent study of picrites and high-MgO basalts from this part of the archipelago highlighted the Pb and Hf isotopic variations and suggested the presence of mantle heterogeneities within the Kerguelen plume itself. We present new helium and neon isotopic compositions for olivines from these picrites and high-MgO basalts (6-17 wt.% MgO) both to constrain the enriched composition of the Kerguelen plume and to determine the origin of isotopic heterogeneities involved in the genesis of Kerguelen plume-related basalts. The olivine phenocrysts have extremely variable 4 He / 3 He compositions between MORB and primitive values observed in OIB (∼90,000 to 40,000; i.e., R / R a ∼8 to 18) and they show primitive neon isotopic ratios (average 21 Ne / 21 Ne ext ∼0.044). The neon isotopic systematics and the 4 He / 3 He ratios that are lower than MORB values for the Kerguelen basalts clearly suggest that the Kerguelen hotspot belongs to the family of primitive hotspots, such as Iceland and Hawaii. The rare gas signature for the Kerguelen samples, intermediate between MORB and solar, is apparently inconsistent with mixing of a primitive component with a MORB-like source, but may result from sampling a heterogeneous part of the mantle with solar 3 He / 22 Ne and with a higher (U, Th) / 3 He ratio compared to typically high R / R a hotspot basalts such as those from Iceland and Hawaii. |
author2 |
Institut de Physique du Globe de Paris (IPGP) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS) Laboratoire Magmas et Volcans (LMV-ENSMSE) École des Mines de Saint-Étienne (Mines Saint-Étienne MSE) Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT)-SPIN-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Magmas et Volcans (LMV) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Doucet, Sonia Moreira, Manuel Weis, Dominique Scoates, James S. Giret, André Allègre, Claude |
author_facet |
Doucet, Sonia Moreira, Manuel Weis, Dominique Scoates, James S. Giret, André Allègre, Claude |
author_sort |
Doucet, Sonia |
title |
Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean |
title_short |
Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean |
title_full |
Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean |
title_fullStr |
Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean |
title_full_unstemmed |
Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean |
title_sort |
primitive neon and helium isotopic compositions of high-mgo basalts from the kerguelen archipelago, indian ocean |
publisher |
HAL CCSD |
publishDate |
2006 |
url |
https://insu.hal.science/insu-03603221 https://doi.org/10.1016/j.epsl.2005.10.025 |
geographic |
Kerguelen Indian |
geographic_facet |
Kerguelen Indian |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
ISSN: 0012-821X Earth and Planetary Science Letters https://insu.hal.science/insu-03603221 Earth and Planetary Science Letters, 2006, 241, pp.65-79. ⟨10.1016/j.epsl.2005.10.025⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2005.10.025 insu-03603221 https://insu.hal.science/insu-03603221 BIBCODE: 2006E&PSL.241.65D doi:10.1016/j.epsl.2005.10.025 |
op_doi |
https://doi.org/10.1016/j.epsl.2005.10.025 |
container_title |
Earth and Planetary Science Letters |
container_volume |
241 |
container_issue |
1-2 |
container_start_page |
65 |
op_container_end_page |
79 |
_version_ |
1802645906763284480 |
spelling |
ftunivparis:oai:HAL:insu-03603221v1 2024-06-23T07:53:59+00:00 Primitive neon and helium isotopic compositions of high-MgO basalts from the Kerguelen Archipelago, Indian Ocean Doucet, Sonia Moreira, Manuel Weis, Dominique Scoates, James S. Giret, André Allègre, Claude Institut de Physique du Globe de Paris (IPGP) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS) Laboratoire Magmas et Volcans (LMV-ENSMSE) École des Mines de Saint-Étienne (Mines Saint-Étienne MSE) Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT)-SPIN-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Magmas et Volcans (LMV) Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS) 2006 https://insu.hal.science/insu-03603221 https://doi.org/10.1016/j.epsl.2005.10.025 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2005.10.025 insu-03603221 https://insu.hal.science/insu-03603221 BIBCODE: 2006E&PSL.241.65D doi:10.1016/j.epsl.2005.10.025 ISSN: 0012-821X Earth and Planetary Science Letters https://insu.hal.science/insu-03603221 Earth and Planetary Science Letters, 2006, 241, pp.65-79. ⟨10.1016/j.epsl.2005.10.025⟩ helium and neon isotopes Kerguelen plume high-MgO basalts olivine mantle [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2006 ftunivparis https://doi.org/10.1016/j.epsl.2005.10.025 2024-06-13T23:39:59Z International audience The geochemical characteristics of mildly alkalic basalts (24-25 Ma) erupted in the southeastern Kerguelen Archipelago are considered to represent the best estimate for the composition of the enriched Kerguelen plume end-member. A recent study of picrites and high-MgO basalts from this part of the archipelago highlighted the Pb and Hf isotopic variations and suggested the presence of mantle heterogeneities within the Kerguelen plume itself. We present new helium and neon isotopic compositions for olivines from these picrites and high-MgO basalts (6-17 wt.% MgO) both to constrain the enriched composition of the Kerguelen plume and to determine the origin of isotopic heterogeneities involved in the genesis of Kerguelen plume-related basalts. The olivine phenocrysts have extremely variable 4 He / 3 He compositions between MORB and primitive values observed in OIB (∼90,000 to 40,000; i.e., R / R a ∼8 to 18) and they show primitive neon isotopic ratios (average 21 Ne / 21 Ne ext ∼0.044). The neon isotopic systematics and the 4 He / 3 He ratios that are lower than MORB values for the Kerguelen basalts clearly suggest that the Kerguelen hotspot belongs to the family of primitive hotspots, such as Iceland and Hawaii. The rare gas signature for the Kerguelen samples, intermediate between MORB and solar, is apparently inconsistent with mixing of a primitive component with a MORB-like source, but may result from sampling a heterogeneous part of the mantle with solar 3 He / 22 Ne and with a higher (U, Th) / 3 He ratio compared to typically high R / R a hotspot basalts such as those from Iceland and Hawaii. Article in Journal/Newspaper Iceland Université de Paris: Portail HAL Kerguelen Indian Earth and Planetary Science Letters 241 1-2 65 79 |