Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica
Thurston Island, and the adjacent Eights Coast and Jones Mountains, record Pacific margin magmatism from Carboniferous to Late Cretaceous times. The igneous rocks form a uniformly calc-alkaline, high-alumina, dominantly metaluminous suite; some relatively fractionated granitoids are mildly peralumin...
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Cambridge University Press
1993
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ftnerc:oai:nora.nerc.ac.uk:517870 2023-05-15T13:49:34+02:00 Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica Leat, Philip T. Storey, Bryan C. Pankhurst, Robert J. 1993-09 http://nora.nerc.ac.uk/id/eprint/517870/ https://doi.org/10.1017/S0954102093000380 unknown Cambridge University Press Leat, Philip T.; Storey, Bryan C.; Pankhurst, Robert J. 1993 Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica. Antarctic Science, 5 (03). 281-296. https://doi.org/10.1017/S0954102093000380 <https://doi.org/10.1017/S0954102093000380> Publication - Article PeerReviewed 1993 ftnerc https://doi.org/10.1017/S0954102093000380 2023-02-04T19:45:24Z Thurston Island, and the adjacent Eights Coast and Jones Mountains, record Pacific margin magmatism from Carboniferous to Late Cretaceous times. The igneous rocks form a uniformly calc-alkaline, high-alumina, dominantly metaluminous suite; some relatively fractionated granitoids are mildly peraluminous. The magmas were hydrous, a result of subduction. Gabbros have compositions outside the range of mafic volcanic and hypabyssal rocks, as a result of cumulate processes. Trace element compositions of the mafic magmas range from a low La/Yb, Th/Ta end-member close to E-MORB in composition, perhaps contaminated by crust, to a high La/Yb, Th/Ta end-member, close to shoshonite, with strong magmatic arc trace element character. This variation may be a result of mixing of tholeiitic and shoshonitic end-members. Most silicic rocks could have been generated batch-wise from mafic magmas by fractional crystallization of a phenocryst assemblage dominated by plagioclase, pyroxene ± amphibole, as seen in the cumulates. Cessation of magmatism at about 90 Ma approximately coincided with collison of a spreading centre between the Phoenix and Pacific oceanic plates with the continent margin subduction zone. The rifting of New Zealand from West Antarctica and associated extension probably was responsible for emplacement of a coast-parallel Cretaceous dyke swarm. Article in Journal/Newspaper Antarc* Antarctic Science Antarctica Thurston Island West Antarctica Natural Environment Research Council: NERC Open Research Archive West Antarctica Pacific New Zealand Thurston ENVELOPE(-97.500,-97.500,-71.833,-71.833) Thurston Island ENVELOPE(-99.000,-99.000,-72.167,-72.167) Jones Mountains ENVELOPE(-94.000,-94.000,-73.667,-73.667) Eights Coast ENVELOPE(-96.000,-96.000,-73.500,-73.500) Antarctic Science 5 3 281 296 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
Thurston Island, and the adjacent Eights Coast and Jones Mountains, record Pacific margin magmatism from Carboniferous to Late Cretaceous times. The igneous rocks form a uniformly calc-alkaline, high-alumina, dominantly metaluminous suite; some relatively fractionated granitoids are mildly peraluminous. The magmas were hydrous, a result of subduction. Gabbros have compositions outside the range of mafic volcanic and hypabyssal rocks, as a result of cumulate processes. Trace element compositions of the mafic magmas range from a low La/Yb, Th/Ta end-member close to E-MORB in composition, perhaps contaminated by crust, to a high La/Yb, Th/Ta end-member, close to shoshonite, with strong magmatic arc trace element character. This variation may be a result of mixing of tholeiitic and shoshonitic end-members. Most silicic rocks could have been generated batch-wise from mafic magmas by fractional crystallization of a phenocryst assemblage dominated by plagioclase, pyroxene ± amphibole, as seen in the cumulates. Cessation of magmatism at about 90 Ma approximately coincided with collison of a spreading centre between the Phoenix and Pacific oceanic plates with the continent margin subduction zone. The rifting of New Zealand from West Antarctica and associated extension probably was responsible for emplacement of a coast-parallel Cretaceous dyke swarm. |
format |
Article in Journal/Newspaper |
author |
Leat, Philip T. Storey, Bryan C. Pankhurst, Robert J. |
spellingShingle |
Leat, Philip T. Storey, Bryan C. Pankhurst, Robert J. Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica |
author_facet |
Leat, Philip T. Storey, Bryan C. Pankhurst, Robert J. |
author_sort |
Leat, Philip T. |
title |
Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica |
title_short |
Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica |
title_full |
Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica |
title_fullStr |
Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica |
title_full_unstemmed |
Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica |
title_sort |
geochemistry of palaeozoic–mesozoic pacific rim orogenic magmatism, thurston island area, west antarctica |
publisher |
Cambridge University Press |
publishDate |
1993 |
url |
http://nora.nerc.ac.uk/id/eprint/517870/ https://doi.org/10.1017/S0954102093000380 |
long_lat |
ENVELOPE(-97.500,-97.500,-71.833,-71.833) ENVELOPE(-99.000,-99.000,-72.167,-72.167) ENVELOPE(-94.000,-94.000,-73.667,-73.667) ENVELOPE(-96.000,-96.000,-73.500,-73.500) |
geographic |
West Antarctica Pacific New Zealand Thurston Thurston Island Jones Mountains Eights Coast |
geographic_facet |
West Antarctica Pacific New Zealand Thurston Thurston Island Jones Mountains Eights Coast |
genre |
Antarc* Antarctic Science Antarctica Thurston Island West Antarctica |
genre_facet |
Antarc* Antarctic Science Antarctica Thurston Island West Antarctica |
op_relation |
Leat, Philip T.; Storey, Bryan C.; Pankhurst, Robert J. 1993 Geochemistry of Palaeozoic–Mesozoic Pacific rim orogenic magmatism, Thurston Island area, West Antarctica. Antarctic Science, 5 (03). 281-296. https://doi.org/10.1017/S0954102093000380 <https://doi.org/10.1017/S0954102093000380> |
op_doi |
https://doi.org/10.1017/S0954102093000380 |
container_title |
Antarctic Science |
container_volume |
5 |
container_issue |
3 |
container_start_page |
281 |
op_container_end_page |
296 |
_version_ |
1766251692749225984 |