Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula
Quantitative estimates of the rates and azimuths of Phoenix plate convergence with the Antarctic Peninsula have been derived from plate rotation calculations for two periods in the Late Cretaceous and early Tertiary (83.0–67.7 and 61.1–53.4 Ma). Published marine magnetic anomaly identifications and...
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Geological Society of London
1998
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ftnerc:oai:nora.nerc.ac.uk:504178 2023-05-15T13:15:17+02:00 Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula McCarron, Joe J. Larter, Robert D. 1998 http://nora.nerc.ac.uk/id/eprint/504178/ https://doi.org/10.1144/gsjgs.155.2.0255 unknown Geological Society of London McCarron, Joe J.; Larter, Robert D. orcid:0000-0002-8414-7389 . 1998 Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula. Journal of the Geological Society, 155 (2). 255-268. https://doi.org/10.1144/gsjgs.155.2.0255 <https://doi.org/10.1144/gsjgs.155.2.0255> Publication - Article PeerReviewed 1998 ftnerc https://doi.org/10.1144/gsjgs.155.2.0255 2023-02-04T19:38:19Z Quantitative estimates of the rates and azimuths of Phoenix plate convergence with the Antarctic Peninsula have been derived from plate rotation calculations for two periods in the Late Cretaceous and early Tertiary (83.0–67.7 and 61.1–53.4 Ma). Published marine magnetic anomaly identifications and ‘flow lines’ interpreted from gravity anomaly maps were used in simple spherical geometry calculations to derive Phoenix–Pacific stage rotations. These were combined with published Pacific–Antarctic rotation data to determine contemporaneous Phoenix–Antarctic stage rotations. The results indicate a significant change in azimuths of relative motion between the Late Cretaceous and early Tertiary. Late Cretaceous, and perhaps earlier, oblique subduction probably caused migration of fore-arc slivers along the margin, resulting in variations in width of the accretionary prism. Comparison between synthetic magnetic profiles and a 900 km long magnetic profile across ocean floor produced at the Antarctic–Phoenix ridge during the early Tertiary establishes the time of a major decrease in spreading rate, and hence also in convergence rate, as chron C23r (52.3 Ma). The associated change in subduction dynamics may have caused the dextral transtensional deformation observed in the George VI Sound region and initiated uplift of blueschist facies rocks now exposed on Smith Island. The calculated convergence history does not provide a simple explanation for the occurrence of high-Mg# andesite lavas on Alexander Island, which were erupted more than 20 Ma before the Antarctic–Phoenix ridge arrived at the margin. The existence of these lavas implies either earlier subduction of another ridge or slab break-up beneath Alexander Island. Article in Journal/Newspaper Alexander Island Antarc* Antarctic Antarctic Peninsula Smith Island Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Antarctic Peninsula Pacific Alexander Island ENVELOPE(-69.895,-69.895,-71.287,-71.287) Smith Island ENVELOPE(-62.520,-62.520,-62.981,-62.981) George VI Sound ENVELOPE(-68.000,-68.000,-71.000,-71.000) Journal of the Geological Society 155 2 255 268 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
Quantitative estimates of the rates and azimuths of Phoenix plate convergence with the Antarctic Peninsula have been derived from plate rotation calculations for two periods in the Late Cretaceous and early Tertiary (83.0–67.7 and 61.1–53.4 Ma). Published marine magnetic anomaly identifications and ‘flow lines’ interpreted from gravity anomaly maps were used in simple spherical geometry calculations to derive Phoenix–Pacific stage rotations. These were combined with published Pacific–Antarctic rotation data to determine contemporaneous Phoenix–Antarctic stage rotations. The results indicate a significant change in azimuths of relative motion between the Late Cretaceous and early Tertiary. Late Cretaceous, and perhaps earlier, oblique subduction probably caused migration of fore-arc slivers along the margin, resulting in variations in width of the accretionary prism. Comparison between synthetic magnetic profiles and a 900 km long magnetic profile across ocean floor produced at the Antarctic–Phoenix ridge during the early Tertiary establishes the time of a major decrease in spreading rate, and hence also in convergence rate, as chron C23r (52.3 Ma). The associated change in subduction dynamics may have caused the dextral transtensional deformation observed in the George VI Sound region and initiated uplift of blueschist facies rocks now exposed on Smith Island. The calculated convergence history does not provide a simple explanation for the occurrence of high-Mg# andesite lavas on Alexander Island, which were erupted more than 20 Ma before the Antarctic–Phoenix ridge arrived at the margin. The existence of these lavas implies either earlier subduction of another ridge or slab break-up beneath Alexander Island. |
format |
Article in Journal/Newspaper |
author |
McCarron, Joe J. Larter, Robert D. |
spellingShingle |
McCarron, Joe J. Larter, Robert D. Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula |
author_facet |
McCarron, Joe J. Larter, Robert D. |
author_sort |
McCarron, Joe J. |
title |
Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula |
title_short |
Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula |
title_full |
Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula |
title_fullStr |
Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula |
title_full_unstemmed |
Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula |
title_sort |
late cretaceous to early tertiary subduction history of the antarctic peninsula |
publisher |
Geological Society of London |
publishDate |
1998 |
url |
http://nora.nerc.ac.uk/id/eprint/504178/ https://doi.org/10.1144/gsjgs.155.2.0255 |
long_lat |
ENVELOPE(-69.895,-69.895,-71.287,-71.287) ENVELOPE(-62.520,-62.520,-62.981,-62.981) ENVELOPE(-68.000,-68.000,-71.000,-71.000) |
geographic |
Antarctic The Antarctic Antarctic Peninsula Pacific Alexander Island Smith Island George VI Sound |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Pacific Alexander Island Smith Island George VI Sound |
genre |
Alexander Island Antarc* Antarctic Antarctic Peninsula Smith Island |
genre_facet |
Alexander Island Antarc* Antarctic Antarctic Peninsula Smith Island |
op_relation |
McCarron, Joe J.; Larter, Robert D. orcid:0000-0002-8414-7389 . 1998 Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula. Journal of the Geological Society, 155 (2). 255-268. https://doi.org/10.1144/gsjgs.155.2.0255 <https://doi.org/10.1144/gsjgs.155.2.0255> |
op_doi |
https://doi.org/10.1144/gsjgs.155.2.0255 |
container_title |
Journal of the Geological Society |
container_volume |
155 |
container_issue |
2 |
container_start_page |
255 |
op_container_end_page |
268 |
_version_ |
1766267884640665600 |