An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean)
International audience Peridotite xenoliths brought up to the surface by the volcanism of the Kerguelen Islands represent a mantle that has been affected by a high degree of partial melting followed by intense melt percolation above the Kerguelen plume. These xenoliths are therefore particularly sui...
Published in: | Geochemistry, Geophysics, Geosystems |
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Main Authors: | , , , , , |
Other Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2008
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Online Access: | https://hal.science/hal-00366222 https://hal.science/hal-00366222/document https://hal.science/hal-00366222/file/bascou_Kerguelen_2007GC001879_hal.pdf https://doi.org/10.1029/2007GC001879 |
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ftunivstetienne:oai:HAL:hal-00366222v1 |
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openpolar |
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Open Polar |
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Université Jean Monnet – Saint-Etienne: HAL |
op_collection_id |
ftunivstetienne |
language |
English |
topic |
Kerguelen mantle plume seismic anisotropy metasomatism crystallographic fabric lithosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Kerguelen mantle plume seismic anisotropy metasomatism crystallographic fabric lithosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Bascou, Jerôme Delpech, G. Vauchez, A. Moine, Bertrand N. Cottin, Jean-Yves Barruol, Guilhem An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean) |
topic_facet |
Kerguelen mantle plume seismic anisotropy metasomatism crystallographic fabric lithosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Peridotite xenoliths brought up to the surface by the volcanism of the Kerguelen Islands represent a mantle that has been affected by a high degree of partial melting followed by intense melt percolation above the Kerguelen plume. These xenoliths are therefore particularly suitable to investigate effects of melt-rock interaction on crystallographic fabrics (lattice-preferred orientation (LPO)) of peridotite minerals and on the LPO-induced seismic properties of peridotites above a mantle plume. We have studied a suite of 16 ultramafic samples representative of different degrees of partial melting and magma-rock interaction among which the protogranular harzburgites are the least metasomatised xenoliths and dunites are the ultimate stage of metasomatism. Olivine LPO is characterized by high concentration of [010] axes perpendicular to the foliation and [100] axes close to the lineation or distributed in the foliation plane in harzburgites, whereas the high concentration of [100] axes is parallel to the lineation and [010] axes is perpendicular to the assumed foliation in dunites. Olivine LPO in harzburgites is interpreted as being due to a deformation regime in axial compression or transpression. The fabric strength of olivine decreases progressively from protogranular to poikilitic harzburgites and finally to dunites, for which it remains nevertheless significant (J index 3.8). Seismic properties calculated from LPO of minerals indicate that metasomatism at higher melt/rock ratio lowers the P wave velocities. The most significant difference between harzburgites and dunites corresponds to the distribution of S wave anisotropy. Harzburgites display the maximum of anisotropy within the foliation plane and the minimum of anisotropy perpendicular to the foliation plane, whereas the lowest anisotropy is parallel to the lineation for dunites. These modifications of seismic properties as a result of metasomatic processes may induce seismic heterogeneities in the mantle above the Kerguelen plume. ... |
author2 |
Laboratoire Magmas et Volcans (LMV) Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS) Interactions et dynamique des environnements de surface (IDES) Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Bascou, Jerôme Delpech, G. Vauchez, A. Moine, Bertrand N. Cottin, Jean-Yves Barruol, Guilhem |
author_facet |
Bascou, Jerôme Delpech, G. Vauchez, A. Moine, Bertrand N. Cottin, Jean-Yves Barruol, Guilhem |
author_sort |
Bascou, Jerôme |
title |
An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean) |
title_short |
An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean) |
title_full |
An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean) |
title_fullStr |
An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean) |
title_full_unstemmed |
An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean) |
title_sort |
integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the kerguelen plume (indian ocean) |
publisher |
HAL CCSD |
publishDate |
2008 |
url |
https://hal.science/hal-00366222 https://hal.science/hal-00366222/document https://hal.science/hal-00366222/file/bascou_Kerguelen_2007GC001879_hal.pdf https://doi.org/10.1029/2007GC001879 |
geographic |
Kerguelen Kerguelen Islands Indian |
geographic_facet |
Kerguelen Kerguelen Islands Indian |
genre |
Kerguelen Islands |
genre_facet |
Kerguelen Islands |
op_source |
ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems https://hal.science/hal-00366222 Geochemistry, Geophysics, Geosystems, 2008, 9 (Q04039), pp.1-26. ⟨10.1029/2007GC001879⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2007GC001879 hal-00366222 https://hal.science/hal-00366222 https://hal.science/hal-00366222/document https://hal.science/hal-00366222/file/bascou_Kerguelen_2007GC001879_hal.pdf doi:10.1029/2007GC001879 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/2007GC001879 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
9 |
container_issue |
4 |
container_start_page |
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n/a |
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1798848932669816832 |
spelling |
ftunivstetienne:oai:HAL:hal-00366222v1 2024-05-12T08:06:26+00:00 An integrated study of microstructural, geochemical, and seismic properties of the lithospheric mantle above the Kerguelen plume (Indian Ocean) Bascou, Jerôme Delpech, G. Vauchez, A. Moine, Bertrand N. Cottin, Jean-Yves Barruol, Guilhem Laboratoire Magmas et Volcans (LMV) Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS) Interactions et dynamique des environnements de surface (IDES) Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) 2008 https://hal.science/hal-00366222 https://hal.science/hal-00366222/document https://hal.science/hal-00366222/file/bascou_Kerguelen_2007GC001879_hal.pdf https://doi.org/10.1029/2007GC001879 en eng HAL CCSD AGU and the Geochemical Society info:eu-repo/semantics/altIdentifier/doi/10.1029/2007GC001879 hal-00366222 https://hal.science/hal-00366222 https://hal.science/hal-00366222/document https://hal.science/hal-00366222/file/bascou_Kerguelen_2007GC001879_hal.pdf doi:10.1029/2007GC001879 info:eu-repo/semantics/OpenAccess ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems https://hal.science/hal-00366222 Geochemistry, Geophysics, Geosystems, 2008, 9 (Q04039), pp.1-26. ⟨10.1029/2007GC001879⟩ Kerguelen mantle plume seismic anisotropy metasomatism crystallographic fabric lithosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2008 ftunivstetienne https://doi.org/10.1029/2007GC001879 2024-04-18T00:24:25Z International audience Peridotite xenoliths brought up to the surface by the volcanism of the Kerguelen Islands represent a mantle that has been affected by a high degree of partial melting followed by intense melt percolation above the Kerguelen plume. These xenoliths are therefore particularly suitable to investigate effects of melt-rock interaction on crystallographic fabrics (lattice-preferred orientation (LPO)) of peridotite minerals and on the LPO-induced seismic properties of peridotites above a mantle plume. We have studied a suite of 16 ultramafic samples representative of different degrees of partial melting and magma-rock interaction among which the protogranular harzburgites are the least metasomatised xenoliths and dunites are the ultimate stage of metasomatism. Olivine LPO is characterized by high concentration of [010] axes perpendicular to the foliation and [100] axes close to the lineation or distributed in the foliation plane in harzburgites, whereas the high concentration of [100] axes is parallel to the lineation and [010] axes is perpendicular to the assumed foliation in dunites. Olivine LPO in harzburgites is interpreted as being due to a deformation regime in axial compression or transpression. The fabric strength of olivine decreases progressively from protogranular to poikilitic harzburgites and finally to dunites, for which it remains nevertheless significant (J index 3.8). Seismic properties calculated from LPO of minerals indicate that metasomatism at higher melt/rock ratio lowers the P wave velocities. The most significant difference between harzburgites and dunites corresponds to the distribution of S wave anisotropy. Harzburgites display the maximum of anisotropy within the foliation plane and the minimum of anisotropy perpendicular to the foliation plane, whereas the lowest anisotropy is parallel to the lineation for dunites. These modifications of seismic properties as a result of metasomatic processes may induce seismic heterogeneities in the mantle above the Kerguelen plume. ... Article in Journal/Newspaper Kerguelen Islands Université Jean Monnet – Saint-Etienne: HAL Kerguelen Kerguelen Islands Indian Geochemistry, Geophysics, Geosystems 9 4 n/a n/a |