Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas
Abstract This study presents an extensive geochemical data set of 23 samples from St. Barthélemy Island, which belongs to the extinct branch of the Lesser Antilles arc and is currently exposed in the northern part of the subduction forearc. Samples were selected to represent all lithologies and main...
Published in: | Geochemistry, Geophysics, Geosystems |
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ftdoajarticles:oai:doaj.org/article:4a8d763121d147968161e2d3d31ac3eb 2023-12-03T10:25:43+01:00 Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas Delphine Bosch Fabienne Zami Mélody Philippon Jean‐Frédéric Lebrun Philippe Münch Jean‐Jacques Cornée Lucie Legendre Alexandre Lemoyne 2022-10-01T00:00:00Z https://doi.org/10.1029/2022GC010482 https://doaj.org/article/4a8d763121d147968161e2d3d31ac3eb EN eng Wiley https://doi.org/10.1029/2022GC010482 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2022GC010482 https://doaj.org/article/4a8d763121d147968161e2d3d31ac3eb Geochemistry, Geophysics, Geosystems, Vol 23, Iss 10, Pp n/a-n/a (2022) geochemistry Lesser Antilles arc isotopes–St. Barthélemy subduction tectonic regime Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.1029/2022GC010482 2023-11-05T01:35:59Z Abstract This study presents an extensive geochemical data set of 23 samples from St. Barthélemy Island, which belongs to the extinct branch of the Lesser Antilles arc and is currently exposed in the northern part of the subduction forearc. Samples were selected to represent all lithologies and main periods of magmatism, that is, Middle‐Late Eocene, Early Oligocene and Late Oligocene. They show enrichment in light rare earth element/medium rare earth element, large ion lithophile elements (Rb and Ba) and isotopic characteristics, suggesting mixing between the mantle and a subduction component (oceanic crust + sediments). Trace element ratios suggest that primary magmas were generated in a normal mid‐oceanic ridge basalt‐type mantle‐wedge that underwent 8%–18% partial melting in the spinel‐stability field. The sediment contribution was low (0.1%–1%) irrespective of the age of the samples. This is similar to what is observed for the northern Lesser Antilles active branch. St. Barthélemy Island shares strong similarities with St. Martin Island, located on the same extinct arc branch, which suggests a similar geodynamic evolution. Oligocene samples displayed an increase in incompatible elements in the magma source, suggesting an increase in sediment melts, which could be correlated with a drastic change in the tectonic regime at that time, characterized by stretching perpendicular to the trench and subsequent basin opening. On Δ7/4Pb versus 206Pb/204Pb, the samples showed a similar trend for both active and extinct islands of the northern Lesser Antilles, suggesting negligible changes in the nature of the magma sources. Article in Journal/Newspaper Martin Island Directory of Open Access Journals: DOAJ Articles Martin Island ENVELOPE(56.967,56.967,-66.733,-66.733) Geochemistry, Geophysics, Geosystems 23 10 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
geochemistry Lesser Antilles arc isotopes–St. Barthélemy subduction tectonic regime Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
geochemistry Lesser Antilles arc isotopes–St. Barthélemy subduction tectonic regime Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 Delphine Bosch Fabienne Zami Mélody Philippon Jean‐Frédéric Lebrun Philippe Münch Jean‐Jacques Cornée Lucie Legendre Alexandre Lemoyne Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas |
topic_facet |
geochemistry Lesser Antilles arc isotopes–St. Barthélemy subduction tectonic regime Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract This study presents an extensive geochemical data set of 23 samples from St. Barthélemy Island, which belongs to the extinct branch of the Lesser Antilles arc and is currently exposed in the northern part of the subduction forearc. Samples were selected to represent all lithologies and main periods of magmatism, that is, Middle‐Late Eocene, Early Oligocene and Late Oligocene. They show enrichment in light rare earth element/medium rare earth element, large ion lithophile elements (Rb and Ba) and isotopic characteristics, suggesting mixing between the mantle and a subduction component (oceanic crust + sediments). Trace element ratios suggest that primary magmas were generated in a normal mid‐oceanic ridge basalt‐type mantle‐wedge that underwent 8%–18% partial melting in the spinel‐stability field. The sediment contribution was low (0.1%–1%) irrespective of the age of the samples. This is similar to what is observed for the northern Lesser Antilles active branch. St. Barthélemy Island shares strong similarities with St. Martin Island, located on the same extinct arc branch, which suggests a similar geodynamic evolution. Oligocene samples displayed an increase in incompatible elements in the magma source, suggesting an increase in sediment melts, which could be correlated with a drastic change in the tectonic regime at that time, characterized by stretching perpendicular to the trench and subsequent basin opening. On Δ7/4Pb versus 206Pb/204Pb, the samples showed a similar trend for both active and extinct islands of the northern Lesser Antilles, suggesting negligible changes in the nature of the magma sources. |
format |
Article in Journal/Newspaper |
author |
Delphine Bosch Fabienne Zami Mélody Philippon Jean‐Frédéric Lebrun Philippe Münch Jean‐Jacques Cornée Lucie Legendre Alexandre Lemoyne |
author_facet |
Delphine Bosch Fabienne Zami Mélody Philippon Jean‐Frédéric Lebrun Philippe Münch Jean‐Jacques Cornée Lucie Legendre Alexandre Lemoyne |
author_sort |
Delphine Bosch |
title |
Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas |
title_short |
Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas |
title_full |
Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas |
title_fullStr |
Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas |
title_full_unstemmed |
Evolution of the Northern Part of the Lesser Antilles Arc—Geochemical Constraints From St. Barthélemy Island Lavas |
title_sort |
evolution of the northern part of the lesser antilles arc—geochemical constraints from st. barthélemy island lavas |
publisher |
Wiley |
publishDate |
2022 |
url |
https://doi.org/10.1029/2022GC010482 https://doaj.org/article/4a8d763121d147968161e2d3d31ac3eb |
long_lat |
ENVELOPE(56.967,56.967,-66.733,-66.733) |
geographic |
Martin Island |
geographic_facet |
Martin Island |
genre |
Martin Island |
genre_facet |
Martin Island |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 23, Iss 10, Pp n/a-n/a (2022) |
op_relation |
https://doi.org/10.1029/2022GC010482 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2022GC010482 https://doaj.org/article/4a8d763121d147968161e2d3d31ac3eb |
op_doi |
https://doi.org/10.1029/2022GC010482 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
23 |
container_issue |
10 |
_version_ |
1784274731498733568 |