The Barreiro suite in the central Ribeira Belt (SE-Brazil): a late Tonian tholeiitic intraplate magmatic event in the distal passive margin of the São Francisco Paleocontinent
| Autor: | Marcela Lobato, Caroline Menezes Nunes de Oliveira, Eduardo Socoloff, Monica Heilbron, Ivo Dussin, Antonio Simonetti, Elton Luiz Dantas, Henrique Bruno, Felipe Corrales, Claudio de Morisson Valeriano |
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| Rok vydání: | 2019 |
| Předmět: |
010506 paleontology
Basalto Geochemistry Lu-Hf 010502 geochemistry & geophysics 01 natural sciences Sm-Nd Passive margin Grupo Andrelândia Andrelândia Group 0105 earth and related environmental sciences Terrane Basalt lcsh:QE1-996.5 U-Pb within-plate basalts Statherian lcsh:Geology Tonian Geocronologia Rhyacian General Earth and Planetary Sciences Island arc Mafic Datação arqueológica Geology |
| Zdroj: | Brazilian Journal of Geology, Vol 49, Iss 2 (2019) Brazilian Journal of Geology v.49 n.2 2019 Brazilian Journal of Geology Sociedade Brasileira de Geologia (SBGEO) instacron:SBGEO Brazilian Journal of Geology, Volume: 49, Issue: 2, Article number: e20180129, Published: 20 MAY 2019 Repositório Institucional da UnB Universidade de Brasília (UnB) instacron:UNB |
| ISSN: | 2317-4692 2317-4889 |
| DOI: | 10.1590/2317-4889201920180129 |
| Popis: | New geochemical, U-Pb, Lu-Hf and Sr-Nd data from the Barreiro Suite metabasites in comparison with enclaves within the distal Andrelândia Group and the orthogranulites of the Juiz de Fora Complex are presented. Geochemical data suggest intraplate setting, with high and low- TiO 2 , TDM Nd ages between 1.80 and 1.41 Ga, negative ENd t and ( 87 Sr/ 86 Sr) i between 0.714 and 0.747. Results contrast with part of the Juiz de Fora Complex enclaves, with island arc tholeiites- calcalkaline basalts (IAT-CAB) geochemical signatures, TDM Nd ages between 2.58 and 2.16 Ga, positive ENd t values and ( 87 Sr/ 86 Sr) i between 0.700 and 0.712. U-Pb data for the Barreiro Suite yielded a crystallization age of 766 ± 13 Ma and a metamorphic overprint of 619 ± 6 Ma. The results indicate three episodes of mafic magmatism in the Occidental terrane of the Ribeira Belt. The two older episodes are related to Rhyacian arc evolution (ca. 2.2 to 2.1 Ga) and to the Statherian (ca. 1.7 Ga) tectonics, and occur only within the Juiz de Fora Complex, while the younger ca. 766 Ma episode constrains the timing of distal passive margin evolution. An important implication is that these late Tonian metabasic rocks could have been a source of detrital zircons for the sedimentation along the distal Andrelândia basin. |
| Databáze: | OpenAIRE |
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