Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction
Abstract The Southern Atlantic-Southwest Indian ridges (SASWIR) host mid-ocean ridge basalts with a residual subduction-related geochemical fingerprint (i.e., a ghost-arc signature) of unclear origin. Here, we show through an analysis of plate kinematic reconstructions and seismic tomography models...
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ftdoajarticles:oai:doaj.org/article:ce5a691371a044f1a10866b02d27b900 2023-06-11T04:04:53+02:00 Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction Guido M. Gianni Jeremías Likerman César R. Navarrete Conrado R. Gianni Sergio Zlotnik 2023-04-01T00:00:00Z https://doi.org/10.1038/s41467-023-37799-w https://doaj.org/article/ce5a691371a044f1a10866b02d27b900 EN eng Nature Portfolio https://doi.org/10.1038/s41467-023-37799-w https://doaj.org/toc/2041-1723 doi:10.1038/s41467-023-37799-w 2041-1723 https://doaj.org/article/ce5a691371a044f1a10866b02d27b900 Nature Communications, Vol 14, Iss 1, Pp 1-13 (2023) Science Q article 2023 ftdoajarticles https://doi.org/10.1038/s41467-023-37799-w 2023-04-23T00:36:37Z Abstract The Southern Atlantic-Southwest Indian ridges (SASWIR) host mid-ocean ridge basalts with a residual subduction-related geochemical fingerprint (i.e., a ghost-arc signature) of unclear origin. Here, we show through an analysis of plate kinematic reconstructions and seismic tomography models that the SASWIR subduction-modified mantle source formed in the Jurassic close to the Georgia Islands slab (GI) and remained near-stationary in the mantle reference frame. In this analysis, the GI lies far inboard the Jurassic Patagonian-Antarctic Peninsula active margin. This was formerly attributed to a large-scale flat subduction event in the Late Triassic-Early Jurassic. We propose that during this flat slab stage, the subduction-modified mantle areas beneath the Mesozoic active margin and surrounding sutures zones may have been bulldozed inland by >2280 km. After the demise of the flat slab, this mantle anomaly remained near-stationary and was sampled by the Karoo mantle plume 183 Million years (Myr) ago and again since 55 Myr ago by the SASWIR. We refer to this process as asthenospheric anomaly telescoping. This study provides a hitherto unrecognized geodynamic effect of flat subduction, the viability of which we support through numerical modeling. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Directory of Open Access Journals: DOAJ Articles Antarctic Antarctic Peninsula Indian Nature Communications 14 1 |
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English |
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Science Q Guido M. Gianni Jeremías Likerman César R. Navarrete Conrado R. Gianni Sergio Zlotnik Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction |
topic_facet |
Science Q |
description |
Abstract The Southern Atlantic-Southwest Indian ridges (SASWIR) host mid-ocean ridge basalts with a residual subduction-related geochemical fingerprint (i.e., a ghost-arc signature) of unclear origin. Here, we show through an analysis of plate kinematic reconstructions and seismic tomography models that the SASWIR subduction-modified mantle source formed in the Jurassic close to the Georgia Islands slab (GI) and remained near-stationary in the mantle reference frame. In this analysis, the GI lies far inboard the Jurassic Patagonian-Antarctic Peninsula active margin. This was formerly attributed to a large-scale flat subduction event in the Late Triassic-Early Jurassic. We propose that during this flat slab stage, the subduction-modified mantle areas beneath the Mesozoic active margin and surrounding sutures zones may have been bulldozed inland by >2280 km. After the demise of the flat slab, this mantle anomaly remained near-stationary and was sampled by the Karoo mantle plume 183 Million years (Myr) ago and again since 55 Myr ago by the SASWIR. We refer to this process as asthenospheric anomaly telescoping. This study provides a hitherto unrecognized geodynamic effect of flat subduction, the viability of which we support through numerical modeling. |
format |
Article in Journal/Newspaper |
author |
Guido M. Gianni Jeremías Likerman César R. Navarrete Conrado R. Gianni Sergio Zlotnik |
author_facet |
Guido M. Gianni Jeremías Likerman César R. Navarrete Conrado R. Gianni Sergio Zlotnik |
author_sort |
Guido M. Gianni |
title |
Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction |
title_short |
Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction |
title_full |
Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction |
title_fullStr |
Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction |
title_full_unstemmed |
Ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction |
title_sort |
ghost-arc geochemical anomaly at a spreading ridge caused by supersized flat subduction |
publisher |
Nature Portfolio |
publishDate |
2023 |
url |
https://doi.org/10.1038/s41467-023-37799-w https://doaj.org/article/ce5a691371a044f1a10866b02d27b900 |
geographic |
Antarctic Antarctic Peninsula Indian |
geographic_facet |
Antarctic Antarctic Peninsula Indian |
genre |
Antarc* Antarctic Antarctic Peninsula |
genre_facet |
Antarc* Antarctic Antarctic Peninsula |
op_source |
Nature Communications, Vol 14, Iss 1, Pp 1-13 (2023) |
op_relation |
https://doi.org/10.1038/s41467-023-37799-w https://doaj.org/toc/2041-1723 doi:10.1038/s41467-023-37799-w 2041-1723 https://doaj.org/article/ce5a691371a044f1a10866b02d27b900 |
op_doi |
https://doi.org/10.1038/s41467-023-37799-w |
container_title |
Nature Communications |
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14 |
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1 |
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1768391584227786752 |