Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance
Geochemical, geochronological, and Lu–Hf isotopic data for mafic–intermediate dykes on Robert Island, West Antarctica, are systematically investigated in order to decipher their petrogenesis and the genetic relationship between the South Shetland Islands and the north‐western Antarctic Peninsula. Th...
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crwiley:10.1002/gj.4402 2024-06-02T07:57:11+00:00 Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance Zheng, Guang‐Gao Liu, Xiaochun Pei, Junling Zhao, Yue Chen, Hong Li, Jianfeng National Natural Science Foundation of China 2022 http://dx.doi.org/10.1002/gj.4402 https://onlinelibrary.wiley.com/doi/pdf/10.1002/gj.4402 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/gj.4402 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Geological Journal volume 57, issue 6, page 2209-2220 ISSN 0072-1050 1099-1034 journal-article 2022 crwiley https://doi.org/10.1002/gj.4402 2024-05-03T12:03:53Z Geochemical, geochronological, and Lu–Hf isotopic data for mafic–intermediate dykes on Robert Island, West Antarctica, are systematically investigated in order to decipher their petrogenesis and the genetic relationship between the South Shetland Islands and the north‐western Antarctic Peninsula. These dykes are enriched in large‐ion lithophile elements with significantly negative Nb and Ta anomalies, and low (Hf/Sm) N and (Nb/La) N and high Ba/La and Ba/Th ratios, with high ε Hf ( t ) values of +8.2 to +14.2. They were derived from partial melting of depleted mantle metasomatized by slab‐derived fluids. Precise ages of 55–54 Ma for the dykes confirm the occurrence of Early Eocene magmatism on Robert Island, corresponding to the final peak of subduction‐related magmatism. The available data suggest that Early Palaeogene (62–54 Ma) igneous rocks on the South Shetland Islands and the north‐western Antarctic Peninsula are products of contemporaneous and different lithofacies magmatism with precursors originating from depleted mantle in a magmatic arc setting. Furthermore, the Early Palaeogene igneous activities were most likely associated with slab rollback and extension in fore‐arc regions resulting from the decreasing convergence rate for the subduction of the Phoenix Plate beneath the Antarctic Plate at ~60 Ma. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Robert Island South Shetland Islands West Antarctica Wiley Online Library Antarctic Antarctic Peninsula Robert Island ENVELOPE(-59.500,-59.500,-62.417,-62.417) South Shetland Islands The Antarctic West Antarctica Geological Journal |
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Open Polar |
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Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Geochemical, geochronological, and Lu–Hf isotopic data for mafic–intermediate dykes on Robert Island, West Antarctica, are systematically investigated in order to decipher their petrogenesis and the genetic relationship between the South Shetland Islands and the north‐western Antarctic Peninsula. These dykes are enriched in large‐ion lithophile elements with significantly negative Nb and Ta anomalies, and low (Hf/Sm) N and (Nb/La) N and high Ba/La and Ba/Th ratios, with high ε Hf ( t ) values of +8.2 to +14.2. They were derived from partial melting of depleted mantle metasomatized by slab‐derived fluids. Precise ages of 55–54 Ma for the dykes confirm the occurrence of Early Eocene magmatism on Robert Island, corresponding to the final peak of subduction‐related magmatism. The available data suggest that Early Palaeogene (62–54 Ma) igneous rocks on the South Shetland Islands and the north‐western Antarctic Peninsula are products of contemporaneous and different lithofacies magmatism with precursors originating from depleted mantle in a magmatic arc setting. Furthermore, the Early Palaeogene igneous activities were most likely associated with slab rollback and extension in fore‐arc regions resulting from the decreasing convergence rate for the subduction of the Phoenix Plate beneath the Antarctic Plate at ~60 Ma. |
author2 |
National Natural Science Foundation of China |
format |
Article in Journal/Newspaper |
author |
Zheng, Guang‐Gao Liu, Xiaochun Pei, Junling Zhao, Yue Chen, Hong Li, Jianfeng |
spellingShingle |
Zheng, Guang‐Gao Liu, Xiaochun Pei, Junling Zhao, Yue Chen, Hong Li, Jianfeng Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance |
author_facet |
Zheng, Guang‐Gao Liu, Xiaochun Pei, Junling Zhao, Yue Chen, Hong Li, Jianfeng |
author_sort |
Zheng, Guang‐Gao |
title |
Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance |
title_short |
Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance |
title_full |
Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance |
title_fullStr |
Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance |
title_full_unstemmed |
Early Palaeogene mafic–intermediate dykes, Robert Island, West Antarctica: Petrogenesis, zircon U–Pb geochronology, and tectonic significance |
title_sort |
early palaeogene mafic–intermediate dykes, robert island, west antarctica: petrogenesis, zircon u–pb geochronology, and tectonic significance |
publisher |
Wiley |
publishDate |
2022 |
url |
http://dx.doi.org/10.1002/gj.4402 https://onlinelibrary.wiley.com/doi/pdf/10.1002/gj.4402 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/gj.4402 |
long_lat |
ENVELOPE(-59.500,-59.500,-62.417,-62.417) |
geographic |
Antarctic Antarctic Peninsula Robert Island South Shetland Islands The Antarctic West Antarctica |
geographic_facet |
Antarctic Antarctic Peninsula Robert Island South Shetland Islands The Antarctic West Antarctica |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Robert Island South Shetland Islands West Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Robert Island South Shetland Islands West Antarctica |
op_source |
Geological Journal volume 57, issue 6, page 2209-2220 ISSN 0072-1050 1099-1034 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/gj.4402 |
container_title |
Geological Journal |
_version_ |
1800739621036883968 |