Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position
Kerguelen basic lavas belong to three magmatic series: transitional, mildly alkaline and highly alkaline, showing from the first to the latter, a general increase in alkali and incompatible element contents as well as some of the incompatible trace element ratios [( Ce Yb)n, Nb Zr, Nb Y, Zr Y, Ti Zr...
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ftunivbruxelles:oai:dipot.ulb.ac.be:2013/188552 2023-05-15T17:02:09+02:00 Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position Gautier, Isabelle Weis, Dominique Mennessier, Jean Paul Vidal, Philippe Giret, André Loubet, Michel 1990 1 full-text file(s): application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/188552 https://dipot.ulb.ac.be/dspace/bitstream/2013/188552/1/Elsevier_172179.pdf en eng uri/info:doi/10.1016/0012-821X(90)90176-X uri/info:pii/0012821X9090176X uri/info:scp/0025596334 https://dipot.ulb.ac.be/dspace/bitstream/2013/188552/1/Elsevier_172179.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/188552 1 full-text file(s): info:eu-repo/semantics/restrictedAccess Earth and planetary science letters, 100 (1-3 Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 1990 ftunivbruxelles 2022-06-12T20:40:02Z Kerguelen basic lavas belong to three magmatic series: transitional, mildly alkaline and highly alkaline, showing from the first to the latter, a general increase in alkali and incompatible element contents as well as some of the incompatible trace element ratios [( Ce Yb)n, Nb Zr, Nb Y, Zr Y, Ti Zr]. Ba Nb, La Nb and all ratios involving Th are in the range of those observed for Dupal type OIBs although subtle differences exist mainly reflecting a slight Th enrichment in the Kerguelen basalts relative to other OIBs. New Sr, Nd and Pb isotope data strengthen the previously identified Dupal signature of Kerguelen rocks. While the transitional series, older than 26 Ma, shows slightly depleted Sr and Nd isotopic signatures ( 87Sr 86Sr < 0.705 and ε{lunate}Nd > 0), the alkaline series, between 26 and about 8 Ma, show a slightly enriched signature which is strengthened in the highly alkaline series ( 87Sr 86Sr up to 0.70056), younger than 12 Ma. Pb isotope ratios do not show any significant difference between these three series. These isotopic data coupled with trace element geochemistry indicate a mixing process between a depleted MORB component and an enriched OIB-type component, the Dupal plume. The Pb isotope characteristics indicate the presence of an old recycled component (continentally derived sediment or crust itself) incorporated into the deep plume source-region which may be responsible for this enrichment. The Kerguelen Islands show a geodynamic evolution from an early ridge centered stage, above or close to the South East Indian Ridge (SEIR) 45 Ma ago, to the present day intraplate setting. The geochemical and isotopic variations reflect this geodynamic evolution and correspond to variable degrees of mixing between the two extreme components (SEIR, MORB and the Kerguelen plume) whose relative proportions evolve with the archipelago position, i.e. with the distance from the ridge at the time of eruption. © 1990. SCOPUS: ar.j info:eu-repo/semantics/published Article in Journal/Newspaper Kerguelen Islands DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Kerguelen Kerguelen Islands Indian |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos |
spellingShingle |
Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos Gautier, Isabelle Weis, Dominique Mennessier, Jean Paul Vidal, Philippe Giret, André Loubet, Michel Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position |
topic_facet |
Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos |
description |
Kerguelen basic lavas belong to three magmatic series: transitional, mildly alkaline and highly alkaline, showing from the first to the latter, a general increase in alkali and incompatible element contents as well as some of the incompatible trace element ratios [( Ce Yb)n, Nb Zr, Nb Y, Zr Y, Ti Zr]. Ba Nb, La Nb and all ratios involving Th are in the range of those observed for Dupal type OIBs although subtle differences exist mainly reflecting a slight Th enrichment in the Kerguelen basalts relative to other OIBs. New Sr, Nd and Pb isotope data strengthen the previously identified Dupal signature of Kerguelen rocks. While the transitional series, older than 26 Ma, shows slightly depleted Sr and Nd isotopic signatures ( 87Sr 86Sr < 0.705 and ε{lunate}Nd > 0), the alkaline series, between 26 and about 8 Ma, show a slightly enriched signature which is strengthened in the highly alkaline series ( 87Sr 86Sr up to 0.70056), younger than 12 Ma. Pb isotope ratios do not show any significant difference between these three series. These isotopic data coupled with trace element geochemistry indicate a mixing process between a depleted MORB component and an enriched OIB-type component, the Dupal plume. The Pb isotope characteristics indicate the presence of an old recycled component (continentally derived sediment or crust itself) incorporated into the deep plume source-region which may be responsible for this enrichment. The Kerguelen Islands show a geodynamic evolution from an early ridge centered stage, above or close to the South East Indian Ridge (SEIR) 45 Ma ago, to the present day intraplate setting. The geochemical and isotopic variations reflect this geodynamic evolution and correspond to variable degrees of mixing between the two extreme components (SEIR, MORB and the Kerguelen plume) whose relative proportions evolve with the archipelago position, i.e. with the distance from the ridge at the time of eruption. © 1990. SCOPUS: ar.j info:eu-repo/semantics/published |
format |
Article in Journal/Newspaper |
author |
Gautier, Isabelle Weis, Dominique Mennessier, Jean Paul Vidal, Philippe Giret, André Loubet, Michel |
author_facet |
Gautier, Isabelle Weis, Dominique Mennessier, Jean Paul Vidal, Philippe Giret, André Loubet, Michel |
author_sort |
Gautier, Isabelle |
title |
Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position |
title_short |
Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position |
title_full |
Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position |
title_fullStr |
Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position |
title_full_unstemmed |
Petrology and geochemistry of the Kerguelen Archipelago basalts (South Indian Ocean): evolution of the mantle sources from ridge to intraplate position |
title_sort |
petrology and geochemistry of the kerguelen archipelago basalts (south indian ocean): evolution of the mantle sources from ridge to intraplate position |
publishDate |
1990 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/188552 https://dipot.ulb.ac.be/dspace/bitstream/2013/188552/1/Elsevier_172179.pdf |
geographic |
Kerguelen Kerguelen Islands Indian |
geographic_facet |
Kerguelen Kerguelen Islands Indian |
genre |
Kerguelen Islands |
genre_facet |
Kerguelen Islands |
op_source |
Earth and planetary science letters, 100 (1-3 |
op_relation |
uri/info:doi/10.1016/0012-821X(90)90176-X uri/info:pii/0012821X9090176X uri/info:scp/0025596334 https://dipot.ulb.ac.be/dspace/bitstream/2013/188552/1/Elsevier_172179.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/188552 |
op_rights |
1 full-text file(s): info:eu-repo/semantics/restrictedAccess |
_version_ |
1766055405719388160 |