Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana
The Ellsworth Mountains of West Antarctica represent part of a displaced terrane once situated along the palaeo-Pacific margin of Gondwana, prior to supercontinent break-up, adjacent to South Africa and the Weddell Sea coast of East Antarctica. Middle Cambrian sedimentary rocks of the southern Ellsw...
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ftnerc:oai:nora.nerc.ac.uk:503166 2023-05-15T13:48:07+02:00 Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana Curtis, Michael L. Leat, Philip T. Riley, Teal R. Storey, Bryan C. Millar, Ian L. Randall, Darren E. 1999 http://nora.nerc.ac.uk/id/eprint/503166/ https://doi.org/10.1016/S0040-1951(99)00033-5 unknown Elsevier Curtis, Michael L.; Leat, Philip T.; Riley, Teal R. orcid:0000-0002-3333-5021 Storey, Bryan C.; Millar, Ian L.; Randall, Darren E. 1999 Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana. Tectonophysics, 304 (4). 275-299. https://doi.org/10.1016/S0040-1951(99)00033-5 <https://doi.org/10.1016/S0040-1951(99)00033-5> Publication - Article PeerReviewed 1999 ftnerc https://doi.org/10.1016/S0040-1951(99)00033-5 2023-02-04T19:37:42Z The Ellsworth Mountains of West Antarctica represent part of a displaced terrane once situated along the palaeo-Pacific margin of Gondwana, prior to supercontinent break-up, adjacent to South Africa and the Weddell Sea coast of East Antarctica. Middle Cambrian sedimentary rocks of the southern Ellsworth Mountains host locally thick volcanic and subvolcanic rocks forming five igneous centres. Geochemically, most of the igneous samples are mafic, with a subordinate suite of evolved types. The mafic suite is geochemically varied, ranging from MORB (mid-ocean ridge basalt)-like compositions to shoshonitic and lamprophyric (e.g. LaN/YbN = 0.95 to 15.2), with εNdi values ranging from +5.2 to −2.0, correlating with Ti/Y. They are interpreted as representing melts derived from more than one mantle source, with the MORB-like rocks being derived from a depleted mantle source, and the more enriched compositions representing partial melting of lithospheric mantle. Silicic rocks contain melt contributions from Late Proterozoic crust, which is inferred to form the basement of the Ellsworth Mountains. We interpret these igneous rocks as having been formed in a continental rift environment, with MORB-like basalts erupted near the rift axis, and melts from lithospheric mantle emplaced on the rift shoulder. Such an interpretation is consistent with the sedimentary host-rock palaeogeography and contemporaneous structures. This Middle Cambrian rift event is correlated spatially and temporally with rift-related sedimentary rocks in South Africa. It is currently unclear what rifted off the southern African–Weddell Sea sector of the Gondwana palaeo-Pacific margin at that time. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Weddell Sea West Antarctica Natural Environment Research Council: NERC Open Research Archive Weddell Sea East Antarctica West Antarctica Pacific Weddell Ellsworth Mountains ENVELOPE(-85.000,-85.000,-78.750,-78.750) Tectonophysics 304 4 275 299 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
unknown |
description |
The Ellsworth Mountains of West Antarctica represent part of a displaced terrane once situated along the palaeo-Pacific margin of Gondwana, prior to supercontinent break-up, adjacent to South Africa and the Weddell Sea coast of East Antarctica. Middle Cambrian sedimentary rocks of the southern Ellsworth Mountains host locally thick volcanic and subvolcanic rocks forming five igneous centres. Geochemically, most of the igneous samples are mafic, with a subordinate suite of evolved types. The mafic suite is geochemically varied, ranging from MORB (mid-ocean ridge basalt)-like compositions to shoshonitic and lamprophyric (e.g. LaN/YbN = 0.95 to 15.2), with εNdi values ranging from +5.2 to −2.0, correlating with Ti/Y. They are interpreted as representing melts derived from more than one mantle source, with the MORB-like rocks being derived from a depleted mantle source, and the more enriched compositions representing partial melting of lithospheric mantle. Silicic rocks contain melt contributions from Late Proterozoic crust, which is inferred to form the basement of the Ellsworth Mountains. We interpret these igneous rocks as having been formed in a continental rift environment, with MORB-like basalts erupted near the rift axis, and melts from lithospheric mantle emplaced on the rift shoulder. Such an interpretation is consistent with the sedimentary host-rock palaeogeography and contemporaneous structures. This Middle Cambrian rift event is correlated spatially and temporally with rift-related sedimentary rocks in South Africa. It is currently unclear what rifted off the southern African–Weddell Sea sector of the Gondwana palaeo-Pacific margin at that time. |
format |
Article in Journal/Newspaper |
author |
Curtis, Michael L. Leat, Philip T. Riley, Teal R. Storey, Bryan C. Millar, Ian L. Randall, Darren E. |
spellingShingle |
Curtis, Michael L. Leat, Philip T. Riley, Teal R. Storey, Bryan C. Millar, Ian L. Randall, Darren E. Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana |
author_facet |
Curtis, Michael L. Leat, Philip T. Riley, Teal R. Storey, Bryan C. Millar, Ian L. Randall, Darren E. |
author_sort |
Curtis, Michael L. |
title |
Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana |
title_short |
Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana |
title_full |
Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana |
title_fullStr |
Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana |
title_full_unstemmed |
Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana |
title_sort |
middle cambrian rift-related volcanism in the ellsworth mountains, antarctica: tectonic implications for the palaeo-pacific margin of gondwana |
publisher |
Elsevier |
publishDate |
1999 |
url |
http://nora.nerc.ac.uk/id/eprint/503166/ https://doi.org/10.1016/S0040-1951(99)00033-5 |
long_lat |
ENVELOPE(-85.000,-85.000,-78.750,-78.750) |
geographic |
Weddell Sea East Antarctica West Antarctica Pacific Weddell Ellsworth Mountains |
geographic_facet |
Weddell Sea East Antarctica West Antarctica Pacific Weddell Ellsworth Mountains |
genre |
Antarc* Antarctica East Antarctica Weddell Sea West Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica Weddell Sea West Antarctica |
op_relation |
Curtis, Michael L.; Leat, Philip T.; Riley, Teal R. orcid:0000-0002-3333-5021 Storey, Bryan C.; Millar, Ian L.; Randall, Darren E. 1999 Middle Cambrian rift-related volcanism in the Ellsworth Mountains, Antarctica: tectonic implications for the palaeo-Pacific margin of Gondwana. Tectonophysics, 304 (4). 275-299. https://doi.org/10.1016/S0040-1951(99)00033-5 <https://doi.org/10.1016/S0040-1951(99)00033-5> |
op_doi |
https://doi.org/10.1016/S0040-1951(99)00033-5 |
container_title |
Tectonophysics |
container_volume |
304 |
container_issue |
4 |
container_start_page |
275 |
op_container_end_page |
299 |
_version_ |
1766248681187573760 |