Evolution of the northern part of the Lesser Antilles arc – Geochemical constraints from St. Barthélemy Island lavas
This study presents an extensive geochemical dataset 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 o...
Main Authors: | , , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Zenodo
2022
|
Subjects: | |
Online Access: | https://doi.org/10.5281/zenodo.6939885 |
id |
ftzenodo:oai:zenodo.org:6939885 |
---|---|
record_format |
openpolar |
spelling |
ftzenodo:oai:zenodo.org:6939885 2024-09-15T18:18:22+00:00 Evolution of the northern part of the Lesser Antilles arc – Geochemical constraints from St. Barthélemy Island lavas Bosch Delphine Zami Fabienne Philippon Mélody Lebrun Jean-Frédéric Munch Philippe Cornee Jean-Jacques Legendre Lucie Lemoyne Alexandre 2022-07-29 https://doi.org/10.5281/zenodo.6939885 unknown Zenodo https://doi.org/10.5281/zenodo.6939884 https://doi.org/10.5281/zenodo.6939885 oai:zenodo.org:6939885 info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode geochemistry - Lesser Antilles arc – isotopes– St. Barthélemy – subduction – tectonic regime info:eu-repo/semantics/article 2022 ftzenodo https://doi.org/10.5281/zenodo.693988510.5281/zenodo.6939884 2024-07-26T14:45:28Z This study presents an extensive geochemical dataset 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, i.e. 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 D7/4Pb versus 206 Pb/ 204 Pb, 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. Keywords: geochemistry - Lesser Antilles arc – isotopes– St. Barthélemy – subduction – tectonic regime Article in Journal/Newspaper Martin Island Zenodo |
institution |
Open Polar |
collection |
Zenodo |
op_collection_id |
ftzenodo |
language |
unknown |
topic |
geochemistry - Lesser Antilles arc – isotopes– St. Barthélemy – subduction – tectonic regime |
spellingShingle |
geochemistry - Lesser Antilles arc – isotopes– St. Barthélemy – subduction – tectonic regime Bosch Delphine Zami Fabienne Philippon Mélody Lebrun Jean-Frédéric Munch Philippe Cornee Jean-Jacques Legendre Lucie Lemoyne Alexandre 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 |
description |
This study presents an extensive geochemical dataset 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, i.e. 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 D7/4Pb versus 206 Pb/ 204 Pb, 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. Keywords: geochemistry - Lesser Antilles arc – isotopes– St. Barthélemy – subduction – tectonic regime |
format |
Article in Journal/Newspaper |
author |
Bosch Delphine Zami Fabienne Philippon Mélody Lebrun Jean-Frédéric Munch Philippe Cornee Jean-Jacques Legendre Lucie Lemoyne Alexandre |
author_facet |
Bosch Delphine Zami Fabienne Philippon Mélody Lebrun Jean-Frédéric Munch Philippe Cornee Jean-Jacques Legendre Lucie Lemoyne Alexandre |
author_sort |
Bosch Delphine |
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 |
Zenodo |
publishDate |
2022 |
url |
https://doi.org/10.5281/zenodo.6939885 |
genre |
Martin Island |
genre_facet |
Martin Island |
op_relation |
https://doi.org/10.5281/zenodo.6939884 https://doi.org/10.5281/zenodo.6939885 oai:zenodo.org:6939885 |
op_rights |
info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.5281/zenodo.693988510.5281/zenodo.6939884 |
_version_ |
1810456490010476544 |