A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group
The Jurassic Mount Poster Formation of eastern Ellsworth Land, southern Antarctic Peninsula, comprises silicic ignimbrites related to intracontinental rifting of Gondwana. The identification of less voluminous basaltic and sedimentary facies marginal to the silicic deposits has led to a reclassifica...
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Cambridge University Press
2006
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ftnerc:oai:nora.nerc.ac.uk:955 2024-06-09T07:40:24+00:00 A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group Hunter, M.A. Riley, T.R. Cantrill, D.J. Flowerdew, M.F. Millar, I.L. 2006 http://nora.nerc.ac.uk/id/eprint/955/ https://doi.org/10.1017/S0016756806002597 unknown Cambridge University Press Hunter, M.A.; Riley, T.R. orcid:0000-0002-3333-5021 Cantrill, D.J.; Flowerdew, M.F.; Millar, I.L. 2006 A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group. Geological Magazine, 143 (6). 777-796. https://doi.org/10.1017/S0016756806002597 <https://doi.org/10.1017/S0016756806002597> Earth Sciences Publication - Article PeerReviewed 2006 ftnerc https://doi.org/10.1017/S0016756806002597 2024-05-15T08:39:04Z The Jurassic Mount Poster Formation of eastern Ellsworth Land, southern Antarctic Peninsula, comprises silicic ignimbrites related to intracontinental rifting of Gondwana. The identification of less voluminous basaltic and sedimentary facies marginal to the silicic deposits has led to a reclassification of the volcanic units into the Ellsworth Land Volcanic Group. This is formally subdivided into two formations: the Mount Poster Formation (silicic ignimbrites), and the Sweeney Formation (basaltic and sedimentary facies). The Mount Poster Formation rhyolites are an intracaldera sequence greater than 1 km in thickness. The basaltic and sedimentary facies of the Sweeney Formation are consistent with deposition in a terrestrial setting into, or close to, water. The geochemistry of the Mount Poster Formation is consistent with derivation of the intracaldera rhyolites from a long-lived, upper crustal magma chamber. The basalts of the Sweeney Formation are intermediate between asthenosphere- and lithosphere-derived magmas, with little or no subduction-modified component. The basalt could represent a rare erupted part of the basaltic underplate that acted as the heat source for local generation of the rhyolites. U–Pb ion microprobe zircon geochronology of samples from the Mount Poster Formation yield an average eruption age of 183.4±1.4 Ma. Analysis of detrital zircons from a Sweeney Formation sandstone suggest a maximum age of deposition of 183±4 Ma and the two formations are considered coeval. In addition, these ages are coincident with eruption of the Karoo-Ferrar Igneous Province in southern Africa and East Antarctica. Our interpretation of the Ellsworth Land Volcanic Group is consistent with the model that the Jurassic volcanism of Patagonia and the Antarctic Peninsula took place in response to intracontinental extension driven by arrival of a plume in that area. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic Antarctic Peninsula East Antarctica Ellsworth Land ENVELOPE(-85.000,-85.000,-75.000,-75.000) Latady ENVELOPE(-65.833,-65.833,-75.500,-75.500) Mount Poster ENVELOPE(-65.652,-65.652,-74.688,-74.688) Patagonia The Antarctic Geological Magazine 143 6 777 796 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Earth Sciences |
spellingShingle |
Earth Sciences Hunter, M.A. Riley, T.R. Cantrill, D.J. Flowerdew, M.F. Millar, I.L. A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group |
topic_facet |
Earth Sciences |
description |
The Jurassic Mount Poster Formation of eastern Ellsworth Land, southern Antarctic Peninsula, comprises silicic ignimbrites related to intracontinental rifting of Gondwana. The identification of less voluminous basaltic and sedimentary facies marginal to the silicic deposits has led to a reclassification of the volcanic units into the Ellsworth Land Volcanic Group. This is formally subdivided into two formations: the Mount Poster Formation (silicic ignimbrites), and the Sweeney Formation (basaltic and sedimentary facies). The Mount Poster Formation rhyolites are an intracaldera sequence greater than 1 km in thickness. The basaltic and sedimentary facies of the Sweeney Formation are consistent with deposition in a terrestrial setting into, or close to, water. The geochemistry of the Mount Poster Formation is consistent with derivation of the intracaldera rhyolites from a long-lived, upper crustal magma chamber. The basalts of the Sweeney Formation are intermediate between asthenosphere- and lithosphere-derived magmas, with little or no subduction-modified component. The basalt could represent a rare erupted part of the basaltic underplate that acted as the heat source for local generation of the rhyolites. U–Pb ion microprobe zircon geochronology of samples from the Mount Poster Formation yield an average eruption age of 183.4±1.4 Ma. Analysis of detrital zircons from a Sweeney Formation sandstone suggest a maximum age of deposition of 183±4 Ma and the two formations are considered coeval. In addition, these ages are coincident with eruption of the Karoo-Ferrar Igneous Province in southern Africa and East Antarctica. Our interpretation of the Ellsworth Land Volcanic Group is consistent with the model that the Jurassic volcanism of Patagonia and the Antarctic Peninsula took place in response to intracontinental extension driven by arrival of a plume in that area. |
format |
Article in Journal/Newspaper |
author |
Hunter, M.A. Riley, T.R. Cantrill, D.J. Flowerdew, M.F. Millar, I.L. |
author_facet |
Hunter, M.A. Riley, T.R. Cantrill, D.J. Flowerdew, M.F. Millar, I.L. |
author_sort |
Hunter, M.A. |
title |
A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group |
title_short |
A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group |
title_full |
A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group |
title_fullStr |
A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group |
title_full_unstemmed |
A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group |
title_sort |
new stratigraphy for the latady basin, antarctic peninsula: part 1, ellsworth land volcanic group |
publisher |
Cambridge University Press |
publishDate |
2006 |
url |
http://nora.nerc.ac.uk/id/eprint/955/ https://doi.org/10.1017/S0016756806002597 |
long_lat |
ENVELOPE(-85.000,-85.000,-75.000,-75.000) ENVELOPE(-65.833,-65.833,-75.500,-75.500) ENVELOPE(-65.652,-65.652,-74.688,-74.688) |
geographic |
Antarctic Antarctic Peninsula East Antarctica Ellsworth Land Latady Mount Poster Patagonia The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula East Antarctica Ellsworth Land Latady Mount Poster Patagonia The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica |
op_relation |
Hunter, M.A.; Riley, T.R. orcid:0000-0002-3333-5021 Cantrill, D.J.; Flowerdew, M.F.; Millar, I.L. 2006 A new stratigraphy for the Latady Basin, Antarctic Peninsula: Part 1, Ellsworth Land Volcanic Group. Geological Magazine, 143 (6). 777-796. https://doi.org/10.1017/S0016756806002597 <https://doi.org/10.1017/S0016756806002597> |
op_doi |
https://doi.org/10.1017/S0016756806002597 |
container_title |
Geological Magazine |
container_volume |
143 |
container_issue |
6 |
container_start_page |
777 |
op_container_end_page |
796 |
_version_ |
1801383818239672320 |