Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil
The basaltic flows from Tapirapuã Formation are exposed at Tangará da Serra region, 250 km from Cuiabá (MT) and the thickness can reach 310 meters. The basalts range from massive dark gray, with colunar disjunctions at the base to purple amygdaloidal at the top. They are generally fine-grained, howe...
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Instituto de Geociências /Universidade Federal do Rio Grande do Sul
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ftunivfrgsojs:oai:seer.ufrgs.br:article/19515 2023-07-16T03:59:59+02:00 Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil Petrografia, Geoquímica, Análises Isotópicas (Sr, Nd) e Geocronologia Ar-Ar dos Basaltos de Tapirapuã (Tangará da Serra, Mato Grosso, Brasil) BARROS, MÁRCIA APARECIDA DE SANT’ANA MIZUSAKI, ANA MARIA WESKA, RICARDO DE BORBA, ANDRÉ CHEMALE JR, FARID DA COSTA, ELISON CARMO 2006-06-29 application/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/19515 por por Instituto de Geociências /Universidade Federal do Rio Grande do Sul https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/19515/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/19515 Pesquisas em Geociências; v. 33 n. 2 (2006): Pesquisas em Geociências; 71 - 77 1807-9806 1518-2398 Tapirapuã basalts petrography geochemistry Mato Grosso Geociências info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2006 ftunivfrgsojs 2023-06-25T21:31:48Z The basaltic flows from Tapirapuã Formation are exposed at Tangará da Serra region, 250 km from Cuiabá (MT) and the thickness can reach 310 meters. The basalts range from massive dark gray, with colunar disjunctions at the base to purple amygdaloidal at the top. They are generally fine-grained, however gabroics portions have been identified. In thin section the Tapirapuã basalts show subophitic texture. Chemical analyses in these rocks suggest tholeiitic compositions, within continental tectonic environment. There is an enrichment of light rare earth elements when compared to heavy rare earth elements. The studied samples have low contents of TiO2 and P2O5 being similar to low P2O5 and TiO2 group from Serra Geral Formation (Paraná Basin). Analyses of Sr and Nd isotopes show the following results: 87Sr/86Sr between 0.703 and 0.707, ∈Nd from –0.01 to + 2.32 and model ages (TDM)= (931 to 1.267 Ma). 40Ar / 39Ar geochronology of plagioclase crystals from Tapirapuã basalts presented a plateau age of 206 ± 6 Ma, in agreement with previous ages obtained from Anari and Tapirapuã sub-provinces. This result places the volcanic event at the limit of the Triassic-Jurassic periods, related to the opening of the North Atlantic. The basaltic flows from Tapirapuã Formation are exposed at Tangará da Serra region, 250 km from Cuiabá (MT) and the thickness can reach 310 meters. The basalts range from massive dark gray, with colunar disjunctions at the base to purple amygdaloidal at the top. They are generally fine-grained, however gabroics portions have been identified. In thin section the Tapirapuã basalts show subophitic texture. Chemical analyses in these rocks suggest tholeiitic compositions, within continental tectonic environment. There is an enrichment of light rare earth elements when compared to heavy rare earth elements. The studied samples have low contents of TiO2 and P2O5 being similar to low P2O5 and TiO2 group from Serra Geral Formation (Paraná Basin). Analyses of Sr and Nd isotopes show the following results: ... Article in Journal/Newspaper North Atlantic Periódicos Científicos da UFRGS (Universidade Federal do Rio Grande do Sul) Pesquisas em Geociências 33 2 71 |
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Open Polar |
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Periódicos Científicos da UFRGS (Universidade Federal do Rio Grande do Sul) |
op_collection_id |
ftunivfrgsojs |
language |
Portuguese |
topic |
Tapirapuã basalts petrography geochemistry Mato Grosso Geociências |
spellingShingle |
Tapirapuã basalts petrography geochemistry Mato Grosso Geociências BARROS, MÁRCIA APARECIDA DE SANT’ANA MIZUSAKI, ANA MARIA WESKA, RICARDO DE BORBA, ANDRÉ CHEMALE JR, FARID DA COSTA, ELISON CARMO Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil |
topic_facet |
Tapirapuã basalts petrography geochemistry Mato Grosso Geociências |
description |
The basaltic flows from Tapirapuã Formation are exposed at Tangará da Serra region, 250 km from Cuiabá (MT) and the thickness can reach 310 meters. The basalts range from massive dark gray, with colunar disjunctions at the base to purple amygdaloidal at the top. They are generally fine-grained, however gabroics portions have been identified. In thin section the Tapirapuã basalts show subophitic texture. Chemical analyses in these rocks suggest tholeiitic compositions, within continental tectonic environment. There is an enrichment of light rare earth elements when compared to heavy rare earth elements. The studied samples have low contents of TiO2 and P2O5 being similar to low P2O5 and TiO2 group from Serra Geral Formation (Paraná Basin). Analyses of Sr and Nd isotopes show the following results: 87Sr/86Sr between 0.703 and 0.707, ∈Nd from –0.01 to + 2.32 and model ages (TDM)= (931 to 1.267 Ma). 40Ar / 39Ar geochronology of plagioclase crystals from Tapirapuã basalts presented a plateau age of 206 ± 6 Ma, in agreement with previous ages obtained from Anari and Tapirapuã sub-provinces. This result places the volcanic event at the limit of the Triassic-Jurassic periods, related to the opening of the North Atlantic. The basaltic flows from Tapirapuã Formation are exposed at Tangará da Serra region, 250 km from Cuiabá (MT) and the thickness can reach 310 meters. The basalts range from massive dark gray, with colunar disjunctions at the base to purple amygdaloidal at the top. They are generally fine-grained, however gabroics portions have been identified. In thin section the Tapirapuã basalts show subophitic texture. Chemical analyses in these rocks suggest tholeiitic compositions, within continental tectonic environment. There is an enrichment of light rare earth elements when compared to heavy rare earth elements. The studied samples have low contents of TiO2 and P2O5 being similar to low P2O5 and TiO2 group from Serra Geral Formation (Paraná Basin). Analyses of Sr and Nd isotopes show the following results: ... |
format |
Article in Journal/Newspaper |
author |
BARROS, MÁRCIA APARECIDA DE SANT’ANA MIZUSAKI, ANA MARIA WESKA, RICARDO DE BORBA, ANDRÉ CHEMALE JR, FARID DA COSTA, ELISON CARMO |
author_facet |
BARROS, MÁRCIA APARECIDA DE SANT’ANA MIZUSAKI, ANA MARIA WESKA, RICARDO DE BORBA, ANDRÉ CHEMALE JR, FARID DA COSTA, ELISON CARMO |
author_sort |
BARROS, MÁRCIA APARECIDA DE SANT’ANA |
title |
Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil |
title_short |
Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil |
title_full |
Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil |
title_fullStr |
Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil |
title_full_unstemmed |
Petrography, geochemistry, Sr and Nd isotope analyses and Ar-Ar geochronology of Tapirapuã Basalts,Tangará da Serra, Mato Grosso, Brasil |
title_sort |
petrography, geochemistry, sr and nd isotope analyses and ar-ar geochronology of tapirapuã basalts,tangará da serra, mato grosso, brasil |
publisher |
Instituto de Geociências /Universidade Federal do Rio Grande do Sul |
publishDate |
2006 |
url |
https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/19515 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Pesquisas em Geociências; v. 33 n. 2 (2006): Pesquisas em Geociências; 71 - 77 1807-9806 1518-2398 |
op_relation |
https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/19515/pdf https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/19515 |
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Pesquisas em Geociências |
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33 |
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2 |
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71 |
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1771548398239875072 |