Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica
Rb-Sr ages of Swanson Formation on Edward VII Peninsula, West Antarctica, indicate a late Ordovician age, 421–432 Ma for regional metamorphism. K-Ar ages of 113–440 Ma, reflect a second thermal metamorphism during emplacement of widespread Cretaceous granites. Rb-Sr ages of five monzogranite/syenogr...
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/s095410209500037x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095410209500037X |
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crcambridgeupr:10.1017/s095410209500037x 2024-06-23T07:47:10+00:00 Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica Adams, C.J. Seward, D. Weaver, S.D. 1995 http://dx.doi.org/10.1017/s095410209500037x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095410209500037X en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Antarctic Science volume 7, issue 3, page 265-276 ISSN 0954-1020 1365-2079 journal-article 1995 crcambridgeupr https://doi.org/10.1017/s095410209500037x 2024-06-12T04:02:19Z Rb-Sr ages of Swanson Formation on Edward VII Peninsula, West Antarctica, indicate a late Ordovician age, 421–432 Ma for regional metamorphism. K-Ar ages of 113–440 Ma, reflect a second thermal metamorphism during emplacement of widespread Cretaceous granites. Rb-Sr ages of five monzogranite/syenogranitic plutons of Byrd Coast Granite are in the range 95–105 Ma (initial 87 Sr/ 86 Sr ratios 0.710–0.715) and represent stages of crystallization of anorogenic granite (A subtype). These correlate with Byrd Coast Granite (100–110 Ma) farther east in Marie Byrd Land, and with Cretaceous granitoids on the Campbell Plateau and in southern New Zealand. K-Ar mica/hornblende and fission-track apatite/zircon ages indicate that regional cooling began c. 90–100 M.y. ago immediately after granite emplacement. Uplift continued throughout the peninsula during the period 55–100 Ma (late Cretaceous-early Tertiary), associated with regional uplift in the rift-drift stages of Gondwana break-up at the South-west Pacific spreading centre. Apatite fission track ages show that during late Cretaceous-early Tertiary time the peninsula behaved as two blocks. The Alexandra Mountains were exhumed 20 m.y. before the Rockefeller Mountains and are possibly separated by a fault active initially in the mid-Cretaceous or earlier, and later reactivated in the late Cretaceous-early Tertiary. An averaged uplift rate (50–100 Ma) of 0.025 mm yr −1 is characteristic of the inferred intraplate tectonic setting. Article in Journal/Newspaper Antarc* Antarctic Science Antarctica Marie Byrd Land West Antarctica Cambridge University Press Alexandra Mountains ENVELOPE(-153.500,-153.500,-77.417,-77.417) Byrd Campbell Plateau ENVELOPE(171.000,171.000,-50.667,-50.667) Edward VII Peninsula ENVELOPE(-155.000,-155.000,-77.667,-77.667) Marie Byrd Land ENVELOPE(-130.000,-130.000,-78.000,-78.000) New Zealand Pacific Rockefeller Mountains ENVELOPE(-155.000,-155.000,-78.000,-78.000) West Antarctica Antarctic Science 7 3 265 276 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Rb-Sr ages of Swanson Formation on Edward VII Peninsula, West Antarctica, indicate a late Ordovician age, 421–432 Ma for regional metamorphism. K-Ar ages of 113–440 Ma, reflect a second thermal metamorphism during emplacement of widespread Cretaceous granites. Rb-Sr ages of five monzogranite/syenogranitic plutons of Byrd Coast Granite are in the range 95–105 Ma (initial 87 Sr/ 86 Sr ratios 0.710–0.715) and represent stages of crystallization of anorogenic granite (A subtype). These correlate with Byrd Coast Granite (100–110 Ma) farther east in Marie Byrd Land, and with Cretaceous granitoids on the Campbell Plateau and in southern New Zealand. K-Ar mica/hornblende and fission-track apatite/zircon ages indicate that regional cooling began c. 90–100 M.y. ago immediately after granite emplacement. Uplift continued throughout the peninsula during the period 55–100 Ma (late Cretaceous-early Tertiary), associated with regional uplift in the rift-drift stages of Gondwana break-up at the South-west Pacific spreading centre. Apatite fission track ages show that during late Cretaceous-early Tertiary time the peninsula behaved as two blocks. The Alexandra Mountains were exhumed 20 m.y. before the Rockefeller Mountains and are possibly separated by a fault active initially in the mid-Cretaceous or earlier, and later reactivated in the late Cretaceous-early Tertiary. An averaged uplift rate (50–100 Ma) of 0.025 mm yr −1 is characteristic of the inferred intraplate tectonic setting. |
format |
Article in Journal/Newspaper |
author |
Adams, C.J. Seward, D. Weaver, S.D. |
spellingShingle |
Adams, C.J. Seward, D. Weaver, S.D. Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica |
author_facet |
Adams, C.J. Seward, D. Weaver, S.D. |
author_sort |
Adams, C.J. |
title |
Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica |
title_short |
Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica |
title_full |
Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica |
title_fullStr |
Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica |
title_full_unstemmed |
Geochronology of Cretaceous granites and metasedimentary basement on Edward VII Peninsula, Marie Byrd Land, West Antarctica |
title_sort |
geochronology of cretaceous granites and metasedimentary basement on edward vii peninsula, marie byrd land, west antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1995 |
url |
http://dx.doi.org/10.1017/s095410209500037x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095410209500037X |
long_lat |
ENVELOPE(-153.500,-153.500,-77.417,-77.417) ENVELOPE(171.000,171.000,-50.667,-50.667) ENVELOPE(-155.000,-155.000,-77.667,-77.667) ENVELOPE(-130.000,-130.000,-78.000,-78.000) ENVELOPE(-155.000,-155.000,-78.000,-78.000) |
geographic |
Alexandra Mountains Byrd Campbell Plateau Edward VII Peninsula Marie Byrd Land New Zealand Pacific Rockefeller Mountains West Antarctica |
geographic_facet |
Alexandra Mountains Byrd Campbell Plateau Edward VII Peninsula Marie Byrd Land New Zealand Pacific Rockefeller Mountains West Antarctica |
genre |
Antarc* Antarctic Science Antarctica Marie Byrd Land West Antarctica |
genre_facet |
Antarc* Antarctic Science Antarctica Marie Byrd Land West Antarctica |
op_source |
Antarctic Science volume 7, issue 3, page 265-276 ISSN 0954-1020 1365-2079 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s095410209500037x |
container_title |
Antarctic Science |
container_volume |
7 |
container_issue |
3 |
container_start_page |
265 |
op_container_end_page |
276 |
_version_ |
1802651251150684160 |