Reavaliação Da Evolução Geológica Em Terrenos Pré-Cambrianos Brasileiros Com Base Em Novos Dados U-Pb Shrimp, Parte Ii: Orógeno Araçuaí, Cinturão Mineiro E Cráton São Francisco Meridional

Silva, Luiz Carlos da; Armstrong, Richard; Noce, Carlos Maurício; Carneiro, Maurício Antônio; Pimentel, Márcio Martins; Pedrosa-Soares, Antônio Carlos; LEITE, CARLOS AUGUSTO; VIEIRA, VÁLTER SALINO; SILVA, MÁRCIO ANTONIO DA; PAES, VINÍCIUS JOSÉ DE CASTRO; FILHO, JOÃO MORAES CARDOSO

doi:10.25249/0375-7536.2002324513528

Cited by 125 publications

(158 citation statements)

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“…5A). The magmatic crystallization age and metamorphic age presented here for the TN-8A amphibolite are equal (considering the analytical errors) to the values obtained in another amphibolite lens in the nearby area (Bananal site) by Silva et al (2002); ■ Sample P2A: meter-thick boudin of amphibolite interleaved in the Pocrane Complex orthogneiss. It features a fine-grained and massive rock, but with quite a distinct foliation.…”

Section: Methodsmentioning

confidence: 99%

“…Despite being regarded as part of the Espinhaço-Chapada Diamantina System (Danderfer et al 2009;Babinski et al 1994Babinski et al , 2012Chemale Jr. et al 2012;Silveira et al 2013;Guadagnin et al 2015), there is only one reference to this event in the Araçuaí Orogen metamorphic core (U-Pb age by Silva et al 2002). The new data from this paper displays a tholeiitic composition amphibolite with crystallization age at 1,529 ± 37 Ma.…”

Section: Continental Basinmentioning

confidence: 96%

“…2) usually occur interlayered in this gneiss (Silva et al 1987;Novo 2013), as sills or tectonic slices. Previous reports on these metamafic rocks (Paes 1999, Silva et al 2002 point out the variability of their genesis. In the available geological maps (Tuller 2000;Féboli & Paes 2000;Oliveira 2000), lenses and layers of ultramafic and metasedimentary rocks (e.g., calcissilicatic rock, mica schist, paragneiss, quartzites, marble and paraconglomerate) were described as intercalations in the Pocrane Complex orthogneiss.…”

Section: Pocrane Complexmentioning

confidence: 99%

“…et al 2003;Heilbron et al 2010). The Calymmian heritage relates to the mafic magmatism represented by amphibolites co-genetic to sample TN-8A (this paper) and Bananal (Silva et al 2002).…”

Section: Methodsmentioning

confidence: 99%

“…The oldest intervals reveal contributions from Rhyacian to Stenian sources, and the absence of pre 2.05 Ga zircon grains discards São Francisco and Congo cratons basement complexes. They also require a younger source with no inheritance, which may correspond mainly to Juiz de Fora and Pocrane basement complexes from Araçuaí-West Congo Orogen (Novo, 2013;Teixeira et al 2000, Silva et al 2002, Barbosa & Sabaté 2004, Noce et al 2007. Correspondingly, the source of this interval could also be associated to rift related granites (e.g., Borrachudos Suite).…”

Section: Continental Basinmentioning

confidence: 99%

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Records of Mesoproterozoic taphrogenic events in the eastern basement of the Araçuaí Orogen, southeast Brazil

et al. 2017

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ABSTRACT:The history of palaeocontinents alternates long fragmentation to drift periods with relatively short agglutination intervals. One of the products of a Rhyacian-Orosirian orogeny was a palaeocontinent that brought together the basement of the Araçuaí-West Congo orogen (AWCO) with regions now located in the São Francisco and Congo cratons. From ca. 2 Ga to ca. 0.7 Ga, this large region of the São Francisco-Congo palaeocontinent was spared of orogenic events, but underwent at least five taphrogenic events recorded by anorogenic magmatism and/or sedimentation. The taphrogenic events are well documented in the AWCO proximal portions and neighboring cratonic regions, but lack evidence in the AWCO high-grade core. Our studies on amphibolites intercalated in the Rhyacian Pocrane complex, basement of the Rio Doce magmatic arc, allowed to the recognition of two Mesoproterozoic taphrogenic episodes. The oldest one, a Calymmian episode, is recorded by amphibolites with a zircon magmatic crystallization age at 1529 ± 37 Ma (U-Pb SHRIMP), and lithochemical signature of basaltic magmatism related to continental intraplate settings. Another set of amphibolite bodies records the youngest taphrogenic episode, a Stenian event, with a zircon magmatic crystallization age at 1096 ± 20 Ma (U-Pb SHRIMP), and lithochemical signature similar to mature magmatism of continental rift setting. The Calymmian episode (ca. 1.5 Ga) correlates to the Espinhaço II basin stage and mafic dikes of the northern Espinhaço, Chapada Diamantina and Curaçá domains, while the Stenian episode (ca. 1.1 Ga) correlates to the Espinhaço III basin stage. We also present U-Pb data for 87 detrital zircon grains from a quartzite lens intercalated in the Pocrane complex, the Córrego Ubá quartzite. Its age spectrum shows main peaks at 1176 ± 21 Ma (35%), 1371 ± 30 Ma (18%), 1536 ± 22 Ma (19%), 1803 ± 36 Ma (17%) and 1977 ± 38 Ma (12%), suggesting a Stenian (ca. 1176 Ma) maximum depositional age (although only one zircon with low discordance shows an age of 955 ± 66 Ma). Comparing with data from the western sector of the Araçuaí orogen and São Francisco craton, it is noteworthy that no igneous zircon from the three samples yielded an age older than early Orosirian (~2.05 Ga), showing age spectra essentially limited in the range of ca. 1-2 Ga; i.e., younger RESUMO:

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Section: Methodsmentioning

confidence: 99%

Section: Continental Basinmentioning

confidence: 96%

Section: Pocrane Complexmentioning

confidence: 99%

“…et al 2003;Heilbron et al 2010). The Calymmian heritage relates to the mafic magmatism represented by amphibolites co-genetic to sample TN-8A (this paper) and Bananal (Silva et al 2002).…”

Section: Methodsmentioning

confidence: 99%

Section: Continental Basinmentioning

confidence: 99%

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Records of Mesoproterozoic taphrogenic events in the eastern basement of the Araçuaí Orogen, southeast Brazil

et al. 2017

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Geological Memories of South Brazilian Landscapes: From Precambrian Orogenesis to the Quaternary Coastal Plain

Menegat

2023

South Brazilian Grasslands

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The Araçuaí Belt

Alkmim

Kuchenbecker

Reis

et al. 2016

São Francisco Craton, Eastern Brazil

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The Araçuaí belts extends along the curved southeastern margin of the São Francisco craton between the Brazilian coast and Lat 21°S, where it merges with the Ribeira belt. It represents the external, basement-involved fold-thrust belt of the Araçuaí-West Congo confined orogen (AWCO), which formed due to the closure of the terminal branch of the Adamastor ocean during the amalgamation of West Gondwana in the Ediacaran and beginning of the Cambrian. Bounded to the east and southeast by the high grade and granitic core of the AWCO, the Araçuaí belt involves a basement assemblage older than 1.8 Ga, the 1.7-0.9 Ga rift to rift-sag successions of the Espinhaço Supergroup, the Tonian-Edicaran rift-passive margin Macaúbas Group, as well as the syn-orogenic Salinas Formation and crustal derived granitic intrusions. The Macaúbas Group, the type unit of the belt, contains a glaciomarine sequence made up of thick diamictites, sandstones and Rapitan-type banded iron formations. The units exposed along the belt were metamorphosed under greenschist to amphibolite facies conditions and affected by thrusts, reverse faults and cratonward verging folds, developed between 575 and 530 Ma. The Araçuaí orogenic front propagates into the craton interior and interacts with preexistent rift structures. This chapter describes the stratigraphic framework and overall structure of the Araçuaí belt, emphasizing the paleogeographic and tectonic significance of its sedimentary and volcanic assemblages.

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Reavaliação Da Evolução Geológica Em Terrenos Pré-Cambrianos Brasileiros Com Base Em Novos Dados U-Pb Shrimp, Parte Ii: Orógeno Araçuaí, Cinturão Mineiro E Cráton São Francisco Meridional

Cited by 125 publications

References 0 publications

Records of Mesoproterozoic taphrogenic events in the eastern basement of the Araçuaí Orogen, southeast Brazil

Records of Mesoproterozoic taphrogenic events in the eastern basement of the Araçuaí Orogen, southeast Brazil

Geological Memories of South Brazilian Landscapes: From Precambrian Orogenesis to the Quaternary Coastal Plain

The Araçuaí Belt

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