Cerium isotope systematics of oceanic carbonatites
International audience Oceanic carbonatites have been reported only at the Cape Verde and Canary archipelagos, North Atlantic Ocean. Geochemical studies based on stable, radiogenic and noble gas isotopes have led to the general consensus that their parental magmas originate in the mantle. Two contra...
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ftinsu:oai:HAL:hal-02570326v1 2023-06-18T03:42:09+02:00 Cerium isotope systematics of oceanic carbonatites Doucelance, Régis Bellot, Nina Boyet, Maud Hammouda, Tahar Laboratoire Magmas et Volcans (LMV) Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-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) Florence, Italy 2013-08-25 https://hal.science/hal-02570326 en eng HAL CCSD hal-02570326 https://hal.science/hal-02570326 Goldschmidt Conference https://hal.science/hal-02570326 Goldschmidt Conference, Aug 2013, Florence, Italy [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry info:eu-repo/semantics/conferenceObject Poster communications 2013 ftinsu 2023-06-05T23:09:21Z International audience Oceanic carbonatites have been reported only at the Cape Verde and Canary archipelagos, North Atlantic Ocean. Geochemical studies based on stable, radiogenic and noble gas isotopes have led to the general consensus that their parental magmas originate in the mantle. Two contrasted models, however, have been proposed for the origin of the carbon of their source: recycled marine carbonates via subduction [Hoernle et al. (2002) Cont. Mineral. Petrol. 142, 520-542; Doucelance et al. (2010) GCA 74, 7261-7282] vs. primordial carbon [Mata et al. (2010) EPSL 291, 70-83].Marine carbonates [Plank & Langmuir (1998) Chem. Geol. 145, 325-394] show REE patterns distinct from those assumed or measured for mantle and mantle-derived reservoirs (D’’: [Tolstikhin et al. (2006) Chem. Geol. 226, 79-99]; Lower Mantle: [Doucelance et al. (2003) GCA 67, 3717- 3733]; DMM: [Workman & Hart (2005) EPSL 231, 53-72]; MORB: [Hofmann (1988) EPSL 90, 297-314]). Notably chondrite-normalized La/Ce and Sm/Nd ratios have inverse values. Consequently old recycled carbonates are likely to display εCe>0 (εCe is the 138Ce/142Ce variation relative to the Bulk Earth x10000) and εNd<0 (143Nd/144Nd variation relative to the Bulk Earth x10000) with time, whereas mantle-related materials will show εCe≤0 and εNd≥0. Thus coupled Ce and Nd isotope systematics appear to be a powerful tool to decipher between the two proposed origins for the carbon of oceanic carbonatites.We have measured Ce and Nd data on carbonatites from the Cape Verde and Canaries archipelagos, together with basaltic samples from the same locations. We have also determined εCe and εNd values for Tamazert carbonatites (Marocco) as it has been proposed that the Cape Verde, Canary and Tamazert carbonatites share a common source [Bouabdellah et al. (2010) J. Petrol. 51, 1655-168]. Our first measurements on oceanic samples argue in favor of recycled marine carbonates in the source of oceanic carbonatites. Conference Object North Atlantic Institut national des sciences de l'Univers: HAL-INSU Hofmann ENVELOPE(160.600,160.600,-82.667,-82.667) Langmuir ENVELOPE(-67.150,-67.150,-66.967,-66.967) Workman ENVELOPE(-65.683,-65.683,-66.392,-66.392) |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
spellingShingle |
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Doucelance, Régis Bellot, Nina Boyet, Maud Hammouda, Tahar Cerium isotope systematics of oceanic carbonatites |
topic_facet |
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry |
description |
International audience Oceanic carbonatites have been reported only at the Cape Verde and Canary archipelagos, North Atlantic Ocean. Geochemical studies based on stable, radiogenic and noble gas isotopes have led to the general consensus that their parental magmas originate in the mantle. Two contrasted models, however, have been proposed for the origin of the carbon of their source: recycled marine carbonates via subduction [Hoernle et al. (2002) Cont. Mineral. Petrol. 142, 520-542; Doucelance et al. (2010) GCA 74, 7261-7282] vs. primordial carbon [Mata et al. (2010) EPSL 291, 70-83].Marine carbonates [Plank & Langmuir (1998) Chem. Geol. 145, 325-394] show REE patterns distinct from those assumed or measured for mantle and mantle-derived reservoirs (D’’: [Tolstikhin et al. (2006) Chem. Geol. 226, 79-99]; Lower Mantle: [Doucelance et al. (2003) GCA 67, 3717- 3733]; DMM: [Workman & Hart (2005) EPSL 231, 53-72]; MORB: [Hofmann (1988) EPSL 90, 297-314]). Notably chondrite-normalized La/Ce and Sm/Nd ratios have inverse values. Consequently old recycled carbonates are likely to display εCe>0 (εCe is the 138Ce/142Ce variation relative to the Bulk Earth x10000) and εNd<0 (143Nd/144Nd variation relative to the Bulk Earth x10000) with time, whereas mantle-related materials will show εCe≤0 and εNd≥0. Thus coupled Ce and Nd isotope systematics appear to be a powerful tool to decipher between the two proposed origins for the carbon of oceanic carbonatites.We have measured Ce and Nd data on carbonatites from the Cape Verde and Canaries archipelagos, together with basaltic samples from the same locations. We have also determined εCe and εNd values for Tamazert carbonatites (Marocco) as it has been proposed that the Cape Verde, Canary and Tamazert carbonatites share a common source [Bouabdellah et al. (2010) J. Petrol. 51, 1655-168]. Our first measurements on oceanic samples argue in favor of recycled marine carbonates in the source of oceanic carbonatites. |
author2 |
Laboratoire Magmas et Volcans (LMV) Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-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) |
format |
Conference Object |
author |
Doucelance, Régis Bellot, Nina Boyet, Maud Hammouda, Tahar |
author_facet |
Doucelance, Régis Bellot, Nina Boyet, Maud Hammouda, Tahar |
author_sort |
Doucelance, Régis |
title |
Cerium isotope systematics of oceanic carbonatites |
title_short |
Cerium isotope systematics of oceanic carbonatites |
title_full |
Cerium isotope systematics of oceanic carbonatites |
title_fullStr |
Cerium isotope systematics of oceanic carbonatites |
title_full_unstemmed |
Cerium isotope systematics of oceanic carbonatites |
title_sort |
cerium isotope systematics of oceanic carbonatites |
publisher |
HAL CCSD |
publishDate |
2013 |
url |
https://hal.science/hal-02570326 |
op_coverage |
Florence, Italy |
long_lat |
ENVELOPE(160.600,160.600,-82.667,-82.667) ENVELOPE(-67.150,-67.150,-66.967,-66.967) ENVELOPE(-65.683,-65.683,-66.392,-66.392) |
geographic |
Hofmann Langmuir Workman |
geographic_facet |
Hofmann Langmuir Workman |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Goldschmidt Conference https://hal.science/hal-02570326 Goldschmidt Conference, Aug 2013, Florence, Italy |
op_relation |
hal-02570326 https://hal.science/hal-02570326 |
_version_ |
1769007978769285120 |