Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly?
The age and origin of the Late Cretaceous magmatism on the North American and Iberian-African margins and the adjacent northern Central and Southern North Atlantic ocean are not well constrained due to the lack of ap- propriate data. To solve this issue, we used the 40Ar/39Ar geochronology and Sr-Nd...
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ftunivgeneve:oai:unige.ch:aou:unige:120450 2023-10-01T03:58:06+02:00 Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly? Merle, Renaud E. Jourdan, Fred Chiaradia, Massimo Olierook, Hugo K.H. Manatschal, Gianreto 2019 https://archive-ouverte.unige.ch/unige:120450 eng eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.lithos.2019.06.002 https://archive-ouverte.unige.ch/unige:120450 unige:120450 info:eu-repo/semantics/restrictedAccess ISSN: 0024-4937 Lithos, vol. 342-343 (2019) p. 480-498 info:eu-repo/classification/ddc/550 Central Atlantic Ocean New England Seamounts Geochronology Cretaceous alkaline magmatism Tore–Madeira Rise info:eu-repo/semantics/article Text Article scientifique info:eu-repo/semantics/publishedVersion 2019 ftunivgeneve https://doi.org/10.1016/j.lithos.2019.06.002 2023-09-07T07:51:11Z The age and origin of the Late Cretaceous magmatism on the North American and Iberian-African margins and the adjacent northern Central and Southern North Atlantic ocean are not well constrained due to the lack of ap- propriate data. To solve this issue, we used the 40Ar/39Ar geochronology and Sr-Nd-Pb isotopes geochemistry of basalts from the New England Seamounts (NES) and the J-Anomaly Ridge (JAR) as these localities on the North American margin are still poorly investigated. We obtained a reliable age of 82.39 ± 0.12 Ma (2σ) for the Nash- ville Seamount (NES) and an alteration age of ca. 76 Ma for the JAR. Our new dates from the New England Sea- mounts, combined with those available from the Tore–Madeira Rise and SW Portugal, on the Iberia–African margins, confirm an overlapping period of activity around 105-80 Ma on both the North American and Iberian-African margins and the adjacent oceanic basins. Plate kinematic reconstructions indicate that these mag- matic occurrences were located within a ~1000 km radius within the yet narrow Atlantic Ocean. The J-Anomaly Ridge samples were most likely formed at the mid-Atlantic ridge around ~120 Ma. The Sr-Nd-Pb initial isotopic ratios from the New England seamounts show similarities with the chemical signa- ture of the Tore–Madeira Rise and, to a lesser extent, SW Portugal. Moreover, New England Seamounts display a trend toward EMI isotopic end-member, similar to those documented in at the Late Cretaceous Godzilla sea- mount on the Tore–Madeira Rise and sills from ODP Site 1276. The shared chemical signature is distributed across a torus-shaped area of ~2000 × 2000 km at a near-fixed location on Earth and is not temporally-controlled, sug- gesting a large-scale chemical anomaly in the shallow mantle. Therefore, geochronological, geochemical and plate reconstructions imply a large-scale, anomalously fertile mantle source that generated widespread magmatism during the Late Cretaceous in the northern Central Atlantic. Article in Journal/Newspaper North Atlantic Université de Genève: Archive ouverte UNIGE Mid-Atlantic Ridge Nash ENVELOPE(-62.350,-62.350,-74.233,-74.233) Nes ENVELOPE(7.634,7.634,62.795,62.795) Nes’ ENVELOPE(44.681,44.681,66.600,66.600) Lithos 342-343 480 498 |
institution |
Open Polar |
collection |
Université de Genève: Archive ouverte UNIGE |
op_collection_id |
ftunivgeneve |
language |
English |
topic |
info:eu-repo/classification/ddc/550 Central Atlantic Ocean New England Seamounts Geochronology Cretaceous alkaline magmatism Tore–Madeira Rise |
spellingShingle |
info:eu-repo/classification/ddc/550 Central Atlantic Ocean New England Seamounts Geochronology Cretaceous alkaline magmatism Tore–Madeira Rise Merle, Renaud E. Jourdan, Fred Chiaradia, Massimo Olierook, Hugo K.H. Manatschal, Gianreto Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly? |
topic_facet |
info:eu-repo/classification/ddc/550 Central Atlantic Ocean New England Seamounts Geochronology Cretaceous alkaline magmatism Tore–Madeira Rise |
description |
The age and origin of the Late Cretaceous magmatism on the North American and Iberian-African margins and the adjacent northern Central and Southern North Atlantic ocean are not well constrained due to the lack of ap- propriate data. To solve this issue, we used the 40Ar/39Ar geochronology and Sr-Nd-Pb isotopes geochemistry of basalts from the New England Seamounts (NES) and the J-Anomaly Ridge (JAR) as these localities on the North American margin are still poorly investigated. We obtained a reliable age of 82.39 ± 0.12 Ma (2σ) for the Nash- ville Seamount (NES) and an alteration age of ca. 76 Ma for the JAR. Our new dates from the New England Sea- mounts, combined with those available from the Tore–Madeira Rise and SW Portugal, on the Iberia–African margins, confirm an overlapping period of activity around 105-80 Ma on both the North American and Iberian-African margins and the adjacent oceanic basins. Plate kinematic reconstructions indicate that these mag- matic occurrences were located within a ~1000 km radius within the yet narrow Atlantic Ocean. The J-Anomaly Ridge samples were most likely formed at the mid-Atlantic ridge around ~120 Ma. The Sr-Nd-Pb initial isotopic ratios from the New England seamounts show similarities with the chemical signa- ture of the Tore–Madeira Rise and, to a lesser extent, SW Portugal. Moreover, New England Seamounts display a trend toward EMI isotopic end-member, similar to those documented in at the Late Cretaceous Godzilla sea- mount on the Tore–Madeira Rise and sills from ODP Site 1276. The shared chemical signature is distributed across a torus-shaped area of ~2000 × 2000 km at a near-fixed location on Earth and is not temporally-controlled, sug- gesting a large-scale chemical anomaly in the shallow mantle. Therefore, geochronological, geochemical and plate reconstructions imply a large-scale, anomalously fertile mantle source that generated widespread magmatism during the Late Cretaceous in the northern Central Atlantic. |
format |
Article in Journal/Newspaper |
author |
Merle, Renaud E. Jourdan, Fred Chiaradia, Massimo Olierook, Hugo K.H. Manatschal, Gianreto |
author_facet |
Merle, Renaud E. Jourdan, Fred Chiaradia, Massimo Olierook, Hugo K.H. Manatschal, Gianreto |
author_sort |
Merle, Renaud E. |
title |
Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly? |
title_short |
Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly? |
title_full |
Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly? |
title_fullStr |
Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly? |
title_full_unstemmed |
Origin of widespread Cretaceous alkaline magmatism in the Central Atlantic: a single melting anomaly? |
title_sort |
origin of widespread cretaceous alkaline magmatism in the central atlantic: a single melting anomaly? |
publishDate |
2019 |
url |
https://archive-ouverte.unige.ch/unige:120450 |
long_lat |
ENVELOPE(-62.350,-62.350,-74.233,-74.233) ENVELOPE(7.634,7.634,62.795,62.795) ENVELOPE(44.681,44.681,66.600,66.600) |
geographic |
Mid-Atlantic Ridge Nash Nes Nes’ |
geographic_facet |
Mid-Atlantic Ridge Nash Nes Nes’ |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0024-4937 Lithos, vol. 342-343 (2019) p. 480-498 |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.lithos.2019.06.002 https://archive-ouverte.unige.ch/unige:120450 unige:120450 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.lithos.2019.06.002 |
container_title |
Lithos |
container_volume |
342-343 |
container_start_page |
480 |
op_container_end_page |
498 |
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1778530556275851264 |