Layered intrusions and volcanic sequences in Central Brazil: Geological and geochronological constraints for Mesoproterozoic (1.25 Ga) and Neoproterozoic (0.79 Ga) igneous associations

Filho, César Fonseca Ferreira; Pimentel, Márcio Martins; Araujo, Sylvia M.; Laux, Jorge Henrique

doi:10.1016/j.precamres.2010.06.008

Cited by 63 publications

(74 citation statements)

References 41 publications

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“…Due to their geological and geochronological similarities, they have been interpreted as representative of an originally single regional-scale structure, which was disrupted during the Brasiliano event forming three individual bodies (Ferreira Filho et al 1998). The three complexes consist of two magmatic systems, distinguished by their petrological and isotopic characteristics (Ferreira Filho et al 1994, Ferreira Filho & Pimentel 2000, Pimentel et al 2004, Ferreira Filho et al 2010.…”

Section: The Barro Alto Niquelândia and Canabrava Mafic-ultramafic Lmentioning

confidence: 99%

“…In addition, previous denominations for the Mesoproterozoic layered units, exposed in the southern and central intrusions, were revisited and, accordingly, they were renamed Serra da Malacacheta and Serra dos Borges complexes, respectively (Ferreira Filho et al 2010). The ages of these two magmatic systems are still controversial.…”

Section: The Barro Alto Niquelândia and Canabrava Mafic-ultramafic Lmentioning

confidence: 99%

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The tectonic evolution of the Neoproterozoic Brasília Belt, central Brazil: a geochronological and isotopic approach

Pimentel

2016

Braz. J. Geol.

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115

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ABSTRACT:The Brasília Belt is one of the most complete Neoproterozoic orogens in western Gondwana. Rapid progress on the understanding of the tectonic evolution of the belt was achieved due to new U-Pb data, combined with Sm-Nd and Lu-Hf analyses. The evolution of the Brasília orogen happened over a long period of time (900 -600 Ma) involving subduction, magmatism and terrain accretion, as a result of the consumption of the Goiás oceanic lithosphere. Provenance studies, based on U-Pb zircon data, indicate that the sedimentary rock units record different tectonic settings and stages of the evolution of the orogen. The Paranoá and Canastra groups represent passive margin sequences derived from the erosion of the São Francisco Craton. The Araxá and Ibiá groups, however, have dominant Neoproterozoic detrital zircon populations, as young as 650 Ma, suggesting derivation from the Goiás Magmatic Arc. The Goiás Magmatic Arc represents a composite arc terrain, formed by the accretion of older (ca. 0.9 -0.8 Ga) intraoceanic island arc(s), followed by more evolved continental arcs. It extends for several thousand kilometers, from SW Goiás, through NE Brazil and into Africa. Metamorphism took place between 650 -630 Ma reflecting final closure of the Goiás Ocean and continental collision. KEYWORDS: Brasília Belt; Neoproterozoic; U-Pb geochronology; Sediment provenance. RESUMO: A Faixa Brasília é um dos mais completos orógenos Neoproterozoicos no Gondwana Ocidental. Durante os últimos dez anos, o rápido progresso no entendimento da evolução tectônica desse orógeno foi proporcionado pela produção de novos dados geocronológicos U-Pb SHRIMP e LA-ICPMS, combinados com análises Sm-Nd e Lu-Hf. Os dados demonstraram que a evolução da Faixa Brasília acontenceu ao longo de um prolongado intervalo de tempo (900 -600 Ma), envolvendo subducção, atividade ígnea e acreção de terrenos, como resultado do consumo da litosfera do oceano Goiás. Estudos de proveniência de sedimentos baseados em geocronologia U-Pb de minerais detríticos indicam que as unidades sedimentares da Faixa

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Section: The Barro Alto Niquelândia and Canabrava Mafic-ultramafic Lmentioning

confidence: 99%

Section: The Barro Alto Niquelândia and Canabrava Mafic-ultramafic Lmentioning

confidence: 99%

The tectonic evolution of the Neoproterozoic Brasília Belt, central Brazil: a geochronological and isotopic approach

Pimentel

2016

Braz. J. Geol.

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115

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“…According to geochemical and geochronological data, the complex was emplaced in the Middle Proterozoic (1560-1600 Ma) as a result of continental rifting and underwent amphibolite to granulite facies metamorphism at about 770-795 Ma [2,3]. Final convergence and continental collision caused deformation and disruption at about 630 Ma [4].…”

Section: Introductionmentioning

confidence: 99%

Platinum-Group Minerals in Chromitites of the Niquelândia Layered Intrusion (Central Goias, Brazil): Their Magmatic Origin and Low-Temperature Reworking during Serpentinization and Lateritic Weathering

et al. 2012

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A variety of platinum-group-minerals (PGM) have been found to occur associated with the chromitite and dunite layers in the Niquelâ ndia igneous complex. Two genetically distinct populations of PGM have been identified corresponding to phases crystallized at high temperatures (primary), and others formed or modified during post-magmatic serpentinization and lateritic weathering (secondary). Primary PGM have been found in moderately serpentinized chromitite and dunite, usually included in fresh chromite grains or partially oxidized interstitial sulfides. Due to topographically controlled lateritic weathering, the silicate rocks are totally transformed to a smectite-kaolinite-garnierite-amorphous silica assemblage, while the chromite is changed into a massive aggregate of a spinel phase having low-Mg and a low Fe especially the Pt-Fe alloys, re-precipitate within the altered chromite together with kaolinite and Fe-hydroxides. Textural evidence suggests that re-deposition of secondary PGM took place during chromite alteration, controlled by variation of the redox conditions on a microscopic scale.

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“…1), the Brasília Belt includes: 1. several metasedimentary units deposited on a Paleoproterozoic sialic basement (Almeida et al 1981, Fuck et al 1993, Pimentel et al 2000; 2. one small allochthonous sialic fragment made dominantly of Archean trondhjemite-tonalite-granodiorite (TTG) terranes and greenstone belts (the Goiás Archean block of Jost et al 2013); 3. three large mafic-ultramafic complexes (Barro Alto, Niquelândia and Cana Brava;Ferreira Filho et al 2010); 4. the Neoproterozoic Goiás Magmatic Arc in the west (for a brief review see Laux et al 2005, Brito-Neves et al 2014); 5. a large Neoproterozoic high-grade terrain known as the Anápolis-Itauçu complex, interpreted as the roots of the Brasília orogen (Piuzana et al 2003.…”

Section: Geological Contextmentioning

confidence: 99%

Granulite-facies metamorphism at ca. 570-580 Ma in the Porangatu Granulite Complex, central Brazil: implications for the evolution of the Transbrasiliano Lineament

et al. 2017

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ABSTRACT:The Porangatu Granulite Complex is exposed in the central part of the Neoproterozoic Tocantins province in central Brazil, along the boundary between the Brasília Belt to the east and the Araguaia Belt to the west. This is part of the transcontinental Transbrasiliano-Kandi shear system. The complex includes garnet-rich enderbite and charnockite, high-grade gneisses as well as lenses of garnet-bearing mafic granulite or amphibolites, and in situ anatectic charnockite, elongated in the NNE-SSW direction along the Talismã Shear Zone (TSZ). These rocks represent suites of ortho-derived rocks of calc-alkaline affinity and small contributions of tholeiitic basalts and aluminous paragneisses. The structural framework records thrust components probably related to the early stages of an oblique collision during the evolution of Neoproterozoic Brasiliano orogens, and can be understood as involving a collisional system of two crustal blocks, initially with thrust components which in its final stage evolved to a transcurrent system with dextral movement. This led to intense imbrication, generation of mylonitic foliation, stretching lineation, tectonic banding and rotation of structures and minerals. The heterogeneous and progressive ductile deformation was accompanied by metamorphic re-equilibrium in late Neoproterozoic time. Granulite facies conditions reached a metamorphic maximum at temperature and pressure above 850°C and 10 kbar, in an almost anhydrous environment, with or without anatexis. Zircon U-Pb SHRIMP analyses for two selected rock samples indicated the combined age of 580 ± 7 Ma for a charnockite and 548 ± 48 Ma for a mafic granulite from which the charnockite is throught to have been derived. The mafic granulite contains zircon grains of ca. 2.1 Ga, indicating Paleoproterozoic igneous protoliths involved in Neoproterozoic high-grade metamorphism. In addition, older inherited zircon grains of ca.

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Layered intrusions and volcanic sequences in Central Brazil: Geological and geochronological constraints for Mesoproterozoic (1.25 Ga) and Neoproterozoic (0.79 Ga) igneous associations

Cited by 63 publications

References 41 publications

The tectonic evolution of the Neoproterozoic Brasília Belt, central Brazil: a geochronological and isotopic approach

The tectonic evolution of the Neoproterozoic Brasília Belt, central Brazil: a geochronological and isotopic approach

Platinum-Group Minerals in Chromitites of the Niquelândia Layered Intrusion (Central Goias, Brazil): Their Magmatic Origin and Low-Temperature Reworking during Serpentinization and Lateritic Weathering

Granulite-facies metamorphism at ca. 570-580 Ma in the Porangatu Granulite Complex, central Brazil: implications for the evolution of the Transbrasiliano Lineament

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