Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex
Abstract Records of Earth's primitive crust are scarce. Eoarchean (older than 3.6 Ga) banded mafic to felsic gneisses have been discovered in the São Francisco Craton, Brazil, pushing back by over 100 million years the oldest gneisses known to date in South America (3.5 Ga). Zircon U‐Pb data yi...
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crwiley:10.1111/ter.12460 2024-09-15T18:13:57+00:00 Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex Oliveira, Elson P. McNaughton, Neal J. Zincone, Stefano A. Talavera, Cristina Fundação de Amparo à Pesquisa do Estado de São Paulo Conselho Nacional de Desenvolvimento Científico e Tecnológico 2020 http://dx.doi.org/10.1111/ter.12460 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fter.12460 https://onlinelibrary.wiley.com/doi/pdf/10.1111/ter.12460 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/ter.12460 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Terra Nova volume 32, issue 4, page 281-289 ISSN 0954-4879 1365-3121 journal-article 2020 crwiley https://doi.org/10.1111/ter.12460 2024-08-06T04:16:17Z Abstract Records of Earth's primitive crust are scarce. Eoarchean (older than 3.6 Ga) banded mafic to felsic gneisses have been discovered in the São Francisco Craton, Brazil, pushing back by over 100 million years the oldest gneisses known to date in South America (3.5 Ga). Zircon U‐Pb data yield rock ages from 3,598 to 3,642 Ma with a few ca. 3.65–3.69 Ga grains suggesting even older rocks in the area. Zircon grains show significantly negative to nearly chondritic initial εHf values and two‐stage model ages from 3.82 to 4.33 Ga, which may indicate the existence of a recycled Hadean to early Eoarchean crust in the region. The felsic gneisses are chemically similar to the low‐pressure Tonalite‐Trondhjemite‐Granodiorite association whereas the mafic gneisses have geochemical signatures that resemble within‐plate basaltic andesite to andesite of Iceland (icelandites). The results are relevant to constrain the composition of Earth's first continental crust. Article in Journal/Newspaper Iceland Wiley Online Library Terra Nova 32 4 281 289 |
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English |
description |
Abstract Records of Earth's primitive crust are scarce. Eoarchean (older than 3.6 Ga) banded mafic to felsic gneisses have been discovered in the São Francisco Craton, Brazil, pushing back by over 100 million years the oldest gneisses known to date in South America (3.5 Ga). Zircon U‐Pb data yield rock ages from 3,598 to 3,642 Ma with a few ca. 3.65–3.69 Ga grains suggesting even older rocks in the area. Zircon grains show significantly negative to nearly chondritic initial εHf values and two‐stage model ages from 3.82 to 4.33 Ga, which may indicate the existence of a recycled Hadean to early Eoarchean crust in the region. The felsic gneisses are chemically similar to the low‐pressure Tonalite‐Trondhjemite‐Granodiorite association whereas the mafic gneisses have geochemical signatures that resemble within‐plate basaltic andesite to andesite of Iceland (icelandites). The results are relevant to constrain the composition of Earth's first continental crust. |
author2 |
Fundação de Amparo à Pesquisa do Estado de São Paulo Conselho Nacional de Desenvolvimento Científico e Tecnológico |
format |
Article in Journal/Newspaper |
author |
Oliveira, Elson P. McNaughton, Neal J. Zincone, Stefano A. Talavera, Cristina |
spellingShingle |
Oliveira, Elson P. McNaughton, Neal J. Zincone, Stefano A. Talavera, Cristina Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex |
author_facet |
Oliveira, Elson P. McNaughton, Neal J. Zincone, Stefano A. Talavera, Cristina |
author_sort |
Oliveira, Elson P. |
title |
Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex |
title_short |
Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex |
title_full |
Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex |
title_fullStr |
Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex |
title_full_unstemmed |
Birthplace of the São Francisco Craton, Brazil: Evidence from 3.60 to 3.64 Ga Gneisses of the Mairi Gneiss Complex |
title_sort |
birthplace of the são francisco craton, brazil: evidence from 3.60 to 3.64 ga gneisses of the mairi gneiss complex |
publisher |
Wiley |
publishDate |
2020 |
url |
http://dx.doi.org/10.1111/ter.12460 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fter.12460 https://onlinelibrary.wiley.com/doi/pdf/10.1111/ter.12460 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/ter.12460 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Terra Nova volume 32, issue 4, page 281-289 ISSN 0954-4879 1365-3121 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/ter.12460 |
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Terra Nova |
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32 |
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4 |
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281 |
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289 |
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1810451729127309312 |