A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation

International audience Low-Ca boninites (LCB) are arc-related magmatic rocks enriched in large ion lithophile elements (LILE), light rare earth elements (LREE), Zr and Hf relative to medium to heavy REE (MREE-HREE). These signatures are commonly attributed to a unique slab-derived agent that metasom...

Full description

Bibliographic Details
Published in:Geochemistry, Geophysics, Geosystems
Main Authors: Bénard, A., Ionov, D. A.
Other Authors: Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet Saint-Étienne (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2012
Subjects:
geo
Online Access:https://doi.org/10.1029/2012GC004145
https://hal.archives-ouvertes.fr/hal-00793975/file/Geochem%20Geophys%20Geosyst%20-%202012%20-%20B%20nard%20-%20A%20new%20petrogenetic%20model%20for%20low%25u2010Ca%20boninites%20Evidence%20from%20veined%20sub%25u2010arc.pdf
https://hal.archives-ouvertes.fr/hal-00793975
id fttriple:oai:gotriple.eu:10670/1.xgguhs
record_format openpolar
spelling fttriple:oai:gotriple.eu:10670/1.xgguhs 2023-05-15T16:58:57+02:00 A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation Bénard, A. Ionov, D. A. Laboratoire Magmas et Volcans (LMV) Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet Saint-Étienne (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) 2012-01-01 https://doi.org/10.1029/2012GC004145 https://hal.archives-ouvertes.fr/hal-00793975/file/Geochem%20Geophys%20Geosyst%20-%202012%20-%20B%20nard%20-%20A%20new%20petrogenetic%20model%20for%20low%25u2010Ca%20boninites%20Evidence%20from%20veined%20sub%25u2010arc.pdf https://hal.archives-ouvertes.fr/hal-00793975 en eng HAL CCSD AGU and the Geochemical Society hal-00793975 doi:10.1029/2012GC004145 10670/1.xgguhs https://hal.archives-ouvertes.fr/hal-00793975/file/Geochem%20Geophys%20Geosyst%20-%202012%20-%20B%20nard%20-%20A%20new%20petrogenetic%20model%20for%20low%25u2010Ca%20boninites%20Evidence%20from%20veined%20sub%25u2010arc.pdf https://hal.archives-ouvertes.fr/hal-00793975 Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 1525-2027 EISSN: 1525-2027 Geochemistry, Geophysics, Geosystems Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2012, 13 (1), pp.Q0AF05. ⟨10.1029/2012GC004145⟩ island arc low-Ca boninite mantle xenolith melt-rock interaction modeling geo archi Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2012 fttriple https://doi.org/10.1029/2012GC004145 2023-01-22T17:03:41Z International audience Low-Ca boninites (LCB) are arc-related magmatic rocks enriched in large ion lithophile elements (LILE), light rare earth elements (LREE), Zr and Hf relative to medium to heavy REE (MREE-HREE). These signatures are commonly attributed to a unique slab-derived agent that metasomatized a depleted mantle source but their origin in such an agent remains enigmatic. We report andesite-hosted refractory spinel harzburgite xenoliths from the Kamchatka arc, which contain a series of orthopyroxene-rich veins; these veins range in thickness, the contents of clinopyroxene and amphibole and degrees of reaction with the host. Vein minerals in reaction zones with host harzburgites show progressive depletion in MREE-HREE at constant Zr-Hf and develop patterns (U-shaped REE with Zr-Hf spikes) that mimic those of LCB. Major and trace element modeling suggests that these veins (1) formed from a high-temperature (≥1400°C), MgO-rich (∼30 wt.%) and silicic (∼54 wt.% SiO2) initial melt, strongly depleted in Al2O3, TiO2and alkalis and (2) record fractionation of the initial melt to form hydrous liquids; the initial melt was equilibrated with metasomatized Kamchatka harzburgites and was similar in trace element abundances to island arc tholeiite (LREE-depleted to flat LREE-MREE patterns, low Nb and Ta but no significant Zr-Hf anomalies, high LILE). We argue that primary magmas of LCB formed by fluid-fluxed (LILE-rich and [Nb, Ta]-depleted fluid) melting of a cpx-free, highly refractory (≥30% melt extraction) harzburgitic source similar to arc peridotites from Kamchatka and elsewhere. This peculiar source may explain the distinctive major element features of LCB primary magmas. We propose that the primary magmas of LCB develop their characteristic trace element patterns through fractionation and reaction with refractory peridotites in the mantle wedge. Slab-related components alone may explain the high LILE in LCB but not their distinctive REE patterns and positive Zr-Hf anomalies. Article in Journal/Newspaper Kamchatka Unknown Geochemistry, Geophysics, Geosystems 13 6 n/a n/a
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic island arc
low-Ca boninite
mantle xenolith
melt-rock interaction
modeling
geo
archi
spellingShingle island arc
low-Ca boninite
mantle xenolith
melt-rock interaction
modeling
geo
archi
Bénard, A.
Ionov, D. A.
A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation
topic_facet island arc
low-Ca boninite
mantle xenolith
melt-rock interaction
modeling
geo
archi
description International audience Low-Ca boninites (LCB) are arc-related magmatic rocks enriched in large ion lithophile elements (LILE), light rare earth elements (LREE), Zr and Hf relative to medium to heavy REE (MREE-HREE). These signatures are commonly attributed to a unique slab-derived agent that metasomatized a depleted mantle source but their origin in such an agent remains enigmatic. We report andesite-hosted refractory spinel harzburgite xenoliths from the Kamchatka arc, which contain a series of orthopyroxene-rich veins; these veins range in thickness, the contents of clinopyroxene and amphibole and degrees of reaction with the host. Vein minerals in reaction zones with host harzburgites show progressive depletion in MREE-HREE at constant Zr-Hf and develop patterns (U-shaped REE with Zr-Hf spikes) that mimic those of LCB. Major and trace element modeling suggests that these veins (1) formed from a high-temperature (≥1400°C), MgO-rich (∼30 wt.%) and silicic (∼54 wt.% SiO2) initial melt, strongly depleted in Al2O3, TiO2and alkalis and (2) record fractionation of the initial melt to form hydrous liquids; the initial melt was equilibrated with metasomatized Kamchatka harzburgites and was similar in trace element abundances to island arc tholeiite (LREE-depleted to flat LREE-MREE patterns, low Nb and Ta but no significant Zr-Hf anomalies, high LILE). We argue that primary magmas of LCB formed by fluid-fluxed (LILE-rich and [Nb, Ta]-depleted fluid) melting of a cpx-free, highly refractory (≥30% melt extraction) harzburgitic source similar to arc peridotites from Kamchatka and elsewhere. This peculiar source may explain the distinctive major element features of LCB primary magmas. We propose that the primary magmas of LCB develop their characteristic trace element patterns through fractionation and reaction with refractory peridotites in the mantle wedge. Slab-related components alone may explain the high LILE in LCB but not their distinctive REE patterns and positive Zr-Hf anomalies.
author2 Laboratoire Magmas et Volcans (LMV)
Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet Saint-Étienne (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC)
Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
format Article in Journal/Newspaper
author Bénard, A.
Ionov, D. A.
author_facet Bénard, A.
Ionov, D. A.
author_sort Bénard, A.
title A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation
title_short A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation
title_full A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation
title_fullStr A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation
title_full_unstemmed A new petrogenetic model for low-Ca boninites: Evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation
title_sort new petrogenetic model for low-ca boninites: evidence from veined sub-arc xenoliths on melt-mantle interaction and melt fractionation
publisher HAL CCSD
publishDate 2012
url https://doi.org/10.1029/2012GC004145
https://hal.archives-ouvertes.fr/hal-00793975/file/Geochem%20Geophys%20Geosyst%20-%202012%20-%20B%20nard%20-%20A%20new%20petrogenetic%20model%20for%20low%25u2010Ca%20boninites%20Evidence%20from%20veined%20sub%25u2010arc.pdf
https://hal.archives-ouvertes.fr/hal-00793975
genre Kamchatka
genre_facet Kamchatka
op_source Hyper Article en Ligne - Sciences de l'Homme et de la Société
ISSN: 1525-2027
EISSN: 1525-2027
Geochemistry, Geophysics, Geosystems
Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2012, 13 (1), pp.Q0AF05. ⟨10.1029/2012GC004145⟩
op_relation hal-00793975
doi:10.1029/2012GC004145
10670/1.xgguhs
https://hal.archives-ouvertes.fr/hal-00793975/file/Geochem%20Geophys%20Geosyst%20-%202012%20-%20B%20nard%20-%20A%20new%20petrogenetic%20model%20for%20low%25u2010Ca%20boninites%20Evidence%20from%20veined%20sub%25u2010arc.pdf
https://hal.archives-ouvertes.fr/hal-00793975
op_doi https://doi.org/10.1029/2012GC004145
container_title Geochemistry, Geophysics, Geosystems
container_volume 13
container_issue 6
container_start_page n/a
op_container_end_page n/a
_version_ 1766051083023548416