Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes
Ocean floor magnetic anomalies show that New Zealand was the last continental fragment to separate from Antarctica during Gondwana break-up, drifting from Marie Byrd Land, West Antarctica, about 84 Ma ago. Prior to continental drift, a voluminous suite of mafic dykes (dated by Ar–Ar laser stepped he...
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Geological Society of London
1999
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Online Access: | http://nora.nerc.ac.uk/id/eprint/503806/ https://doi.org/10.1144/gsjgs.156.4.0659 |
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ftnerc:oai:nora.nerc.ac.uk:503806 2023-05-15T13:48:08+02:00 Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes Storey, Bryan C. Leat, Philip T. Weaver, Stephen D. Pankhurst, Robert J. Bradshaw, John D. Kelley, Simon 1999 http://nora.nerc.ac.uk/id/eprint/503806/ https://doi.org/10.1144/gsjgs.156.4.0659 unknown Geological Society of London Storey, Bryan C.; Leat, Philip T.; Weaver, Stephen D.; Pankhurst, Robert J.; Bradshaw, John D.; Kelley, Simon. 1999 Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes. Journal of the Geological Society, 156 (4). 659-671. https://doi.org/10.1144/gsjgs.156.4.0659 <https://doi.org/10.1144/gsjgs.156.4.0659> Publication - Article PeerReviewed 1999 ftnerc https://doi.org/10.1144/gsjgs.156.4.0659 2023-02-04T19:38:02Z Ocean floor magnetic anomalies show that New Zealand was the last continental fragment to separate from Antarctica during Gondwana break-up, drifting from Marie Byrd Land, West Antarctica, about 84 Ma ago. Prior to continental drift, a voluminous suite of mafic dykes (dated by Ar–Ar laser stepped heating at 107 ± 5 Ma) and anorogenic silicic rocks, including syenites and peralkaline granitoids (95–102 Ma), were emplaced in Marie Byrd Land during a rifting event. The mafic dyke suite includes both high- and low-Ti basalts. Trace element and Sr and Nd isotope compositions of the mafic dykes may be modelled by mixing between tholeiitic OIB (asthenosphere-derived) and alkaline high- to low-Ti alkaline magmas (lithospheric mantle derived). Pb isotopes indicate that the OIB component had a HIMU composition. We suggest that the rift-related magmatism was generated in the vicinity of a mantle plume. The plume helped to control the position of continental separation within the very wide region of continental extension that developed when the Pacific–Phoenix spreading ridge approached the subduction zone. Separation of New Zealand from Antarctica occurred when the Pacific–Phoenix spreading centre propagated into the Antarctic continent. Sea floor spreading in the region of the mantle plume may have caused an outburst of volcanism along the spreading ridge generating an oceanic plateau, now represented by the 10–15 km thick Hikurangi Plateau situated alongside the Chatham Rise, New Zealand. The plateau consists of tholeiitic OIB-MORB basalt, regarded as Cretaceous in age, and similar in composition to the putative tholeiitic end-member in the Marie Byrd Land dykes. The mantle plume is proposed to now underlie the western Ross Sea, centred beneath Mount Erebus, where it was largely responsible for the very voluminous, intraplate, alkaline McMurdo Volcanic Group. A second mantle plume beneath Marie Byrd Land formed the Cenozoic alkaline volcanic province. Article in Journal/Newspaper Antarc* Antarctic Antarctica Antarctica New Zealand Marie Byrd Land Ross Sea West Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Ross Sea West Antarctica Pacific New Zealand Byrd Marie Byrd Land ENVELOPE(-130.000,-130.000,-78.000,-78.000) Mount Erebus ENVELOPE(167.167,167.167,-77.533,-77.533) Journal of the Geological Society 156 4 659 671 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
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description |
Ocean floor magnetic anomalies show that New Zealand was the last continental fragment to separate from Antarctica during Gondwana break-up, drifting from Marie Byrd Land, West Antarctica, about 84 Ma ago. Prior to continental drift, a voluminous suite of mafic dykes (dated by Ar–Ar laser stepped heating at 107 ± 5 Ma) and anorogenic silicic rocks, including syenites and peralkaline granitoids (95–102 Ma), were emplaced in Marie Byrd Land during a rifting event. The mafic dyke suite includes both high- and low-Ti basalts. Trace element and Sr and Nd isotope compositions of the mafic dykes may be modelled by mixing between tholeiitic OIB (asthenosphere-derived) and alkaline high- to low-Ti alkaline magmas (lithospheric mantle derived). Pb isotopes indicate that the OIB component had a HIMU composition. We suggest that the rift-related magmatism was generated in the vicinity of a mantle plume. The plume helped to control the position of continental separation within the very wide region of continental extension that developed when the Pacific–Phoenix spreading ridge approached the subduction zone. Separation of New Zealand from Antarctica occurred when the Pacific–Phoenix spreading centre propagated into the Antarctic continent. Sea floor spreading in the region of the mantle plume may have caused an outburst of volcanism along the spreading ridge generating an oceanic plateau, now represented by the 10–15 km thick Hikurangi Plateau situated alongside the Chatham Rise, New Zealand. The plateau consists of tholeiitic OIB-MORB basalt, regarded as Cretaceous in age, and similar in composition to the putative tholeiitic end-member in the Marie Byrd Land dykes. The mantle plume is proposed to now underlie the western Ross Sea, centred beneath Mount Erebus, where it was largely responsible for the very voluminous, intraplate, alkaline McMurdo Volcanic Group. A second mantle plume beneath Marie Byrd Land formed the Cenozoic alkaline volcanic province. |
format |
Article in Journal/Newspaper |
author |
Storey, Bryan C. Leat, Philip T. Weaver, Stephen D. Pankhurst, Robert J. Bradshaw, John D. Kelley, Simon |
spellingShingle |
Storey, Bryan C. Leat, Philip T. Weaver, Stephen D. Pankhurst, Robert J. Bradshaw, John D. Kelley, Simon Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes |
author_facet |
Storey, Bryan C. Leat, Philip T. Weaver, Stephen D. Pankhurst, Robert J. Bradshaw, John D. Kelley, Simon |
author_sort |
Storey, Bryan C. |
title |
Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes |
title_short |
Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes |
title_full |
Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes |
title_fullStr |
Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes |
title_full_unstemmed |
Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes |
title_sort |
mantle plumes and antarctica-new zealand rifting: evidence from mid-cretaceous mafic dykes |
publisher |
Geological Society of London |
publishDate |
1999 |
url |
http://nora.nerc.ac.uk/id/eprint/503806/ https://doi.org/10.1144/gsjgs.156.4.0659 |
long_lat |
ENVELOPE(-130.000,-130.000,-78.000,-78.000) ENVELOPE(167.167,167.167,-77.533,-77.533) |
geographic |
Antarctic The Antarctic Ross Sea West Antarctica Pacific New Zealand Byrd Marie Byrd Land Mount Erebus |
geographic_facet |
Antarctic The Antarctic Ross Sea West Antarctica Pacific New Zealand Byrd Marie Byrd Land Mount Erebus |
genre |
Antarc* Antarctic Antarctica Antarctica New Zealand Marie Byrd Land Ross Sea West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Antarctica New Zealand Marie Byrd Land Ross Sea West Antarctica |
op_relation |
Storey, Bryan C.; Leat, Philip T.; Weaver, Stephen D.; Pankhurst, Robert J.; Bradshaw, John D.; Kelley, Simon. 1999 Mantle plumes and Antarctica-New Zealand rifting: evidence from mid-Cretaceous mafic dykes. Journal of the Geological Society, 156 (4). 659-671. https://doi.org/10.1144/gsjgs.156.4.0659 <https://doi.org/10.1144/gsjgs.156.4.0659> |
op_doi |
https://doi.org/10.1144/gsjgs.156.4.0659 |
container_title |
Journal of the Geological Society |
container_volume |
156 |
container_issue |
4 |
container_start_page |
659 |
op_container_end_page |
671 |
_version_ |
1766248702464229376 |