Ages of the Magmatism and the Opening of the South Atlantic Ocean
The analysis of published and unpublished 368 K/Ar radiometric ages of basic, intermediate and alkaline volcanic rocks, related to the post-Paleozoic magmatism linked to the opening of the South Atlantic Ocean, yields some important evidence concerning the break up of the Gondwana supercontinent. At...
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Instituto de Geociências /Universidade Federal do Rio Grande do Sul
1998
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Online Access: | https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/21166 |
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ftunivfrgsojs:oai:seer.ufrgs.br:article/21166 2023-07-16T04:00:52+02:00 Ages of the Magmatism and the Opening of the South Atlantic Ocean MIZUSAKI, ANA MARIA PIMENTEL THOMAZ FILHO, ANTONIO DE CESERO, PEDRO 1998-12-31 application/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/21166 por por Instituto de Geociências /Universidade Federal do Rio Grande do Sul https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/21166/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/21166 Pesquisas em Geociências; v. 25 n. 2 (1998): Pesquisas; 47-57 1807-9806 1518-2398 radiometric ages magmatism South Atlantic Ocean Geociências info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1998 ftunivfrgsojs 2023-06-25T21:32:03Z The analysis of published and unpublished 368 K/Ar radiometric ages of basic, intermediate and alkaline volcanic rocks, related to the post-Paleozoic magmatism linked to the opening of the South Atlantic Ocean, yields some important evidence concerning the break up of the Gondwana supercontinent. At the Brazilian Equatorial margin, the Gondwana break up started in the Permo-Triassic, when the opening of the Equatorial South Atlantic Ocean began and spread out south-eastward up to the present day Amazon River mouth. During the middle Jurassic/lower Cretaceous (pre-Aptian), the continuity of this separation, towards the Potiguar Basin, was coeval with the northward opening of the south-east Brazilian margin, up to the Espírito Santo State latitude. The relationship between large volcanic events in the basins and the resistance to the rifting process development offered by the cratonic area was shown by the trend of the magmatic age. Along the equatorial margin, the fragmentation resistance caused by the São Luis / West African craton is manifested by a large basic magmatism described in the Tacutu, Acre, Solimões, Amazonas and Parnaíba basins. A similar mechanism along the south-east margin, is proposed for the magmatism described in the Paraná Basin which is associated with the fracturing resistance offered by the São Francisco/Congo cratonic area. The integration of geochronological, micropalentological, sedimentological and geochemical data from the basins of the east Brazilian continental margin supports a model to explain the final disruption between South America and Africa during Cenonian/Turonian time. This model implies that 90 Ma basic magmatic rocks, related to the oceanic crust formation, probably occur offshore from the present-day eastern Brazilian coast line. Article in Journal/Newspaper South Atlantic Ocean Periódicos Científicos da UFRGS (Universidade Federal do Rio Grande do Sul) Pesquisas em Geociências 25 2 47 |
institution |
Open Polar |
collection |
Periódicos Científicos da UFRGS (Universidade Federal do Rio Grande do Sul) |
op_collection_id |
ftunivfrgsojs |
language |
Portuguese |
topic |
radiometric ages magmatism South Atlantic Ocean Geociências |
spellingShingle |
radiometric ages magmatism South Atlantic Ocean Geociências MIZUSAKI, ANA MARIA PIMENTEL THOMAZ FILHO, ANTONIO DE CESERO, PEDRO Ages of the Magmatism and the Opening of the South Atlantic Ocean |
topic_facet |
radiometric ages magmatism South Atlantic Ocean Geociências |
description |
The analysis of published and unpublished 368 K/Ar radiometric ages of basic, intermediate and alkaline volcanic rocks, related to the post-Paleozoic magmatism linked to the opening of the South Atlantic Ocean, yields some important evidence concerning the break up of the Gondwana supercontinent. At the Brazilian Equatorial margin, the Gondwana break up started in the Permo-Triassic, when the opening of the Equatorial South Atlantic Ocean began and spread out south-eastward up to the present day Amazon River mouth. During the middle Jurassic/lower Cretaceous (pre-Aptian), the continuity of this separation, towards the Potiguar Basin, was coeval with the northward opening of the south-east Brazilian margin, up to the Espírito Santo State latitude. The relationship between large volcanic events in the basins and the resistance to the rifting process development offered by the cratonic area was shown by the trend of the magmatic age. Along the equatorial margin, the fragmentation resistance caused by the São Luis / West African craton is manifested by a large basic magmatism described in the Tacutu, Acre, Solimões, Amazonas and Parnaíba basins. A similar mechanism along the south-east margin, is proposed for the magmatism described in the Paraná Basin which is associated with the fracturing resistance offered by the São Francisco/Congo cratonic area. The integration of geochronological, micropalentological, sedimentological and geochemical data from the basins of the east Brazilian continental margin supports a model to explain the final disruption between South America and Africa during Cenonian/Turonian time. This model implies that 90 Ma basic magmatic rocks, related to the oceanic crust formation, probably occur offshore from the present-day eastern Brazilian coast line. |
format |
Article in Journal/Newspaper |
author |
MIZUSAKI, ANA MARIA PIMENTEL THOMAZ FILHO, ANTONIO DE CESERO, PEDRO |
author_facet |
MIZUSAKI, ANA MARIA PIMENTEL THOMAZ FILHO, ANTONIO DE CESERO, PEDRO |
author_sort |
MIZUSAKI, ANA MARIA PIMENTEL |
title |
Ages of the Magmatism and the Opening of the South Atlantic Ocean |
title_short |
Ages of the Magmatism and the Opening of the South Atlantic Ocean |
title_full |
Ages of the Magmatism and the Opening of the South Atlantic Ocean |
title_fullStr |
Ages of the Magmatism and the Opening of the South Atlantic Ocean |
title_full_unstemmed |
Ages of the Magmatism and the Opening of the South Atlantic Ocean |
title_sort |
ages of the magmatism and the opening of the south atlantic ocean |
publisher |
Instituto de Geociências /Universidade Federal do Rio Grande do Sul |
publishDate |
1998 |
url |
https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/21166 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
Pesquisas em Geociências; v. 25 n. 2 (1998): Pesquisas; 47-57 1807-9806 1518-2398 |
op_relation |
https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/21166/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/21166 |
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Pesquisas em Geociências |
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25 |
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47 |
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1771550131063095296 |