Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana
New SHRIMP U–Pb zircon, Rb–Sr whole-rock, and 40Ar–39Ar data are presented for the Jurassic silicic volcanic rocks and related granitoids of Patagonia and the Antarctic Peninsula. U–Pb is the only reliable method for dating crystallization in these rocks; Rb–Sr is prone to hydrothermal resetting and...
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Oxford University Press
2000
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ftnerc:oai:nora.nerc.ac.uk:21182 2023-05-15T13:45:12+02:00 Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana Pankhurst, R.J. Riley, T.R. Fanning, C.M. Kelley, S.P. 2000 http://nora.nerc.ac.uk/id/eprint/21182/ https://doi.org/10.1093/petrology/41.5.605 unknown Oxford University Press Pankhurst, R.J.; Riley, T.R. orcid:0000-0002-3333-5021 Fanning, C.M.; Kelley, S.P. 2000 Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana. Journal of Petrology, 41 (5). 605-625. https://doi.org/10.1093/petrology/41.5.605 <https://doi.org/10.1093/petrology/41.5.605> Publication - Article PeerReviewed 2000 ftnerc https://doi.org/10.1093/petrology/41.5.605 2023-02-04T19:33:17Z New SHRIMP U–Pb zircon, Rb–Sr whole-rock, and 40Ar–39Ar data are presented for the Jurassic silicic volcanic rocks and related granitoids of Patagonia and the Antarctic Peninsula. U–Pb is the only reliable method for dating crystallization in these rocks; Rb–Sr is prone to hydrothermal resetting and Ar–Ar is additionally affected by initial excess 40Ar. Volcanism spanned more than 30 My, but three episodes are defined on the basis of peak activity: V1 (188–178 Ma), V2 (172–162 Ma) and V3 (157–153 Ma). The first essentially coincides with the Karoo–Ferrar mafic magmatism of South Africa, Antarctica and Tasmania. The silicic products of V1 are lower-crustal melts that have incorporated upper-crustal material. The geochemistry of V2 and V3 ignimbrites is more characteristic of destructive plate margins, but the presence of inherited zircon still points to a crustal source. The pattern of volcanism corresponds in space and in time to migration away from the Karoo mantle plume towards the proto-Pacific margin of Gondwana during rifting and break-up. The heat required to initiate bulk crustal fusion may have been supplied by the spreading plume-head, but thinning of the crust during continental dispersion would also have facilitated anatexis. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Antarctic Peninsula Patagonia Pacific Journal of Petrology 41 5 605 625 |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
New SHRIMP U–Pb zircon, Rb–Sr whole-rock, and 40Ar–39Ar data are presented for the Jurassic silicic volcanic rocks and related granitoids of Patagonia and the Antarctic Peninsula. U–Pb is the only reliable method for dating crystallization in these rocks; Rb–Sr is prone to hydrothermal resetting and Ar–Ar is additionally affected by initial excess 40Ar. Volcanism spanned more than 30 My, but three episodes are defined on the basis of peak activity: V1 (188–178 Ma), V2 (172–162 Ma) and V3 (157–153 Ma). The first essentially coincides with the Karoo–Ferrar mafic magmatism of South Africa, Antarctica and Tasmania. The silicic products of V1 are lower-crustal melts that have incorporated upper-crustal material. The geochemistry of V2 and V3 ignimbrites is more characteristic of destructive plate margins, but the presence of inherited zircon still points to a crustal source. The pattern of volcanism corresponds in space and in time to migration away from the Karoo mantle plume towards the proto-Pacific margin of Gondwana during rifting and break-up. The heat required to initiate bulk crustal fusion may have been supplied by the spreading plume-head, but thinning of the crust during continental dispersion would also have facilitated anatexis. |
format |
Article in Journal/Newspaper |
author |
Pankhurst, R.J. Riley, T.R. Fanning, C.M. Kelley, S.P. |
spellingShingle |
Pankhurst, R.J. Riley, T.R. Fanning, C.M. Kelley, S.P. Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana |
author_facet |
Pankhurst, R.J. Riley, T.R. Fanning, C.M. Kelley, S.P. |
author_sort |
Pankhurst, R.J. |
title |
Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana |
title_short |
Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana |
title_full |
Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana |
title_fullStr |
Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana |
title_full_unstemmed |
Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana |
title_sort |
episodic silicic volcanism in patagonia and the antarctic peninsula: chronology of magmatism associated with the break-up of gondwana |
publisher |
Oxford University Press |
publishDate |
2000 |
url |
http://nora.nerc.ac.uk/id/eprint/21182/ https://doi.org/10.1093/petrology/41.5.605 |
geographic |
Antarctic The Antarctic Antarctic Peninsula Patagonia Pacific |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Patagonia Pacific |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica |
op_relation |
Pankhurst, R.J.; Riley, T.R. orcid:0000-0002-3333-5021 Fanning, C.M.; Kelley, S.P. 2000 Episodic silicic volcanism in Patagonia and the Antarctic Peninsula: Chronology of magmatism associated with the break-up of Gondwana. Journal of Petrology, 41 (5). 605-625. https://doi.org/10.1093/petrology/41.5.605 <https://doi.org/10.1093/petrology/41.5.605> |
op_doi |
https://doi.org/10.1093/petrology/41.5.605 |
container_title |
Journal of Petrology |
container_volume |
41 |
container_issue |
5 |
container_start_page |
605 |
op_container_end_page |
625 |
_version_ |
1766217283932258304 |