The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province
The field occurrence, age, classification and geochemistry of the Mesozoic volcanic rocks of Patagonia and West Antarctica are reviewed, using published and new information. Dominated by rhyolitic ignimbrites, which form a bimodal association with minor mafic and intermediate lavas, these constitute...
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1998
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ftnerc:oai:nora.nerc.ac.uk:504224 2023-05-15T13:48:08+02:00 The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province Pankhurst, R.J Leat, P.T. Sruoga, P Rapela, C.W Márquez, M Storey, B.C Riley, T.R. 1998 http://nora.nerc.ac.uk/id/eprint/504224/ https://doi.org/10.1016/S0377-0273(97)00070-X unknown Elsevier Pankhurst, R.J; Leat, P.T.; Sruoga, P; Rapela, C.W; Márquez, M; Storey, B.C; Riley, T.R. orcid:0000-0002-3333-5021 . 1998 The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province. Journal of Volcanology and Geothermal Research, 81 (1-2). 113-136. https://doi.org/10.1016/S0377-0273(97)00070-X <https://doi.org/10.1016/S0377-0273(97)00070-X> Publication - Article PeerReviewed 1998 ftnerc https://doi.org/10.1016/S0377-0273(97)00070-X 2023-02-04T19:38:19Z The field occurrence, age, classification and geochemistry of the Mesozoic volcanic rocks of Patagonia and West Antarctica are reviewed, using published and new information. Dominated by rhyolitic ignimbrites, which form a bimodal association with minor mafic and intermediate lavas, these constitute one of the largest silicic igneous provinces known, equivalent in size to many mafic LIPs. Diachronism is recognized between the Early–Middle Jurassic volcanism of eastern Patagonia (Marifil and Chon Aike formations) and the Middle Jurassic–earliest Cretaceous volcanism of the Andean Cordillera (El Quemado, Ibañez and Tobı́fera formations). This is accompanied by a change in geochemical characteristics, from relatively high-Zr and -Nb types in the east to subalkaline arc-related rocks in the west, although the predominance of rhyolites remains a constant factor. All of the associated mafic rocks are well fractionated compared to direct mantle derivatives. Petrogenetic models favour partial melting of immature lower crust as a result of the intrusion of basaltic magmas, possibly with some hybridisation of the liquids and subsequent fractionation by crystal settling or solidification and remelting. The formation of large amounts of intracrustal silicic melt acted as a density barrier against the further rise of mafic magmas, which are thus rare in the province. Article in Journal/Newspaper Antarc* Antarctica West Antarctica Natural Environment Research Council: NERC Open Research Archive Patagonia West Antarctica Ibañez ENVELOPE(-58.100,-58.100,-64.250,-64.250) Journal of Volcanology and Geothermal Research 81 1-2 113 136 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
The field occurrence, age, classification and geochemistry of the Mesozoic volcanic rocks of Patagonia and West Antarctica are reviewed, using published and new information. Dominated by rhyolitic ignimbrites, which form a bimodal association with minor mafic and intermediate lavas, these constitute one of the largest silicic igneous provinces known, equivalent in size to many mafic LIPs. Diachronism is recognized between the Early–Middle Jurassic volcanism of eastern Patagonia (Marifil and Chon Aike formations) and the Middle Jurassic–earliest Cretaceous volcanism of the Andean Cordillera (El Quemado, Ibañez and Tobı́fera formations). This is accompanied by a change in geochemical characteristics, from relatively high-Zr and -Nb types in the east to subalkaline arc-related rocks in the west, although the predominance of rhyolites remains a constant factor. All of the associated mafic rocks are well fractionated compared to direct mantle derivatives. Petrogenetic models favour partial melting of immature lower crust as a result of the intrusion of basaltic magmas, possibly with some hybridisation of the liquids and subsequent fractionation by crystal settling or solidification and remelting. The formation of large amounts of intracrustal silicic melt acted as a density barrier against the further rise of mafic magmas, which are thus rare in the province. |
format |
Article in Journal/Newspaper |
author |
Pankhurst, R.J Leat, P.T. Sruoga, P Rapela, C.W Márquez, M Storey, B.C Riley, T.R. |
spellingShingle |
Pankhurst, R.J Leat, P.T. Sruoga, P Rapela, C.W Márquez, M Storey, B.C Riley, T.R. The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province |
author_facet |
Pankhurst, R.J Leat, P.T. Sruoga, P Rapela, C.W Márquez, M Storey, B.C Riley, T.R. |
author_sort |
Pankhurst, R.J |
title |
The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province |
title_short |
The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province |
title_full |
The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province |
title_fullStr |
The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province |
title_full_unstemmed |
The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province |
title_sort |
chon aike province of patagonia and related rocks in west antarctica: a silicic large igneous province |
publisher |
Elsevier |
publishDate |
1998 |
url |
http://nora.nerc.ac.uk/id/eprint/504224/ https://doi.org/10.1016/S0377-0273(97)00070-X |
long_lat |
ENVELOPE(-58.100,-58.100,-64.250,-64.250) |
geographic |
Patagonia West Antarctica Ibañez |
geographic_facet |
Patagonia West Antarctica Ibañez |
genre |
Antarc* Antarctica West Antarctica |
genre_facet |
Antarc* Antarctica West Antarctica |
op_relation |
Pankhurst, R.J; Leat, P.T.; Sruoga, P; Rapela, C.W; Márquez, M; Storey, B.C; Riley, T.R. orcid:0000-0002-3333-5021 . 1998 The Chon Aike province of Patagonia and related rocks in West Antarctica: A silicic large igneous province. Journal of Volcanology and Geothermal Research, 81 (1-2). 113-136. https://doi.org/10.1016/S0377-0273(97)00070-X <https://doi.org/10.1016/S0377-0273(97)00070-X> |
op_doi |
https://doi.org/10.1016/S0377-0273(97)00070-X |
container_title |
Journal of Volcanology and Geothermal Research |
container_volume |
81 |
container_issue |
1-2 |
container_start_page |
113 |
op_container_end_page |
136 |
_version_ |
1766248727670947840 |