The Mesoproterozoic Mucajai Anorthosite - Mangerite - Rapakivi Granite Complex, Amazonian Craton, Brazil

Fraga, Lêda Maria Barreto; Dall’Agnol, Roberto; Costa, Joao Batista Sena; Macambira, Moacir José Buenano

doi:10.3749/canmin.47.6.1469

Cited by 28 publications

(10 citation statements)

References 51 publications

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“…On the Brazilian side, this episode is mainly registered in the Roraima State, within of the Guyana Central belt geological domain (Fraga & Reis 1996). According to Fraga and Reis (1996), Fraga (2002) and Fraga et al (2009), the K´Mudku episode produced a set of brittle-ductile shear zones with NE-SW foliation, as well as contraction and strike-slip faults with cataclasite generation, with partial to total obliteration on to Paleo-to Mesoproterozoic pre-existing structures, developed by a lithospheric transpression mechanism at the low-grade metamorphic conditions. On the other hand, Santos et al (2006b) argue that the K'Mudku episode was a collisional zone active for approximately 300 Ma, which produced sinistral thrustsshear zone oblique at medium to high-grade metamorphic conditions and occurrence of bimodal magmatism.…”

Section: Geological Settingmentioning

confidence: 99%

“…1A). The K´Mudku event produced mylonitization and cataclasites, marked by several pulses resetting K-Ar and Rb-Sr isotopic systems of Paleoproterozoic units and local rock melting (Barron 1966, Priem et al 1971, Bosma et al 1983, Gibbs & Barron 1993, Fraga & Reis 1996, Santos et al 2000, 2008, Fraga 2002, Fraga et al 2009, Cordani et al 2010. This event has been considered to be a structural far-field effect of the GrenvillianSunsas orogenies affecting the central-north part of the Amazon craton associated to an intracratonic tectonic setting (Teixeira 1978, Santos et al 2000, 2006b, 2008, Cordani et al 2010.…”

Section: Introductionmentioning

confidence: 99%

“…Although Mesoproterozoic (1.55 -1.54 Ga) A-type magmatic units are known since the 1970s in the southernmost Guyana shield, especially in the State of Roraima, such as the Surucucus and Mucajaí intrusive suites (Montalvão et al 1975, Gaudette et al 1996, CPRM 1999, Fraga et al 2009, Almeida et al 2003. Records of Mesoproterozoic A-type magmatism chronologically associated to K´Mudku deformational event leads to the debate on the tectonic evolution in the central-north Amazon craton, emphasizing the geological/tectonic events responsible for the generation of A-type granites during the Ectasian-Stenian period.…”

Section: Introductionmentioning

confidence: 99%

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K'Mudku A-type magmatism in the southernmost Guyana Shield, central-north Amazon Craton (Brazil): the case of Pedra do Gavião syenogranite

Souza

Dantas

et al. 2015

Braz. J. Geol.

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<p>The Mesoproterozoic K'Mudku event (1490 - 1147 Ma) is represented by a britlle-ductile shear belt that cuts across the Paleoproterozoic units in the southernmost Guyana shield, central-north Amazon craton. This event produced mylonitization and cataclasites at low/medium- to high-grade metamorphic, and local within-plate magmatism. In the Amazonas State, Brazil, A-type magmatism chronologically associated to K'Mudku has been reported for the Pedra do Gavião and Samaúma syenogranites. However, the spatial relationship between K´Mudku event and A-type magma generation are not yet adequately clarified in the region. The Pedra do Gavião syenogranite is a high-K alkaline, metaluminous, reduced A-type granite with a post-collisional to within-plate geochemical signature. It has U-Pb zircons crystallization age of 1218 Ma and inherited zircons with ages between 1820 and 1720 Ma, which, together with the Sm-Nd data, suggest melting of Paleoproterozoic basement rocks of the Cauaburi Complex (1810 - 1780 Ma) regional unit. These data demonstrate that the effects of the A-type magmatism associated to the end of the Grenvillian-Sunsas orogeny, reported primarily in the southwestern margin of the Amazon craton, may also be extended for the central-northern part of the Amazon craton. Probably the generation or emplacement mechanisms of A-type magma occurred with some degree of involvement in the final stages of the K´Mudku event. However, this tectonic framework conception still needs more geological and geophysical investigations. Therefore, these news data should instigate to the return of geological research in the region, as well as to debate on the tectonic evolution and A-type granites production during the Ectasian-Stenian period in the central-north Amazon craton.</p>

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Section: Geological Settingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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K'Mudku A-type magmatism in the southernmost Guyana Shield, central-north Amazon Craton (Brazil): the case of Pedra do Gavião syenogranite

Souza

Dantas

et al. 2015

Braz. J. Geol.

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“…No Cráton Amazônico granitos rapakivi de idade Mesoproterozóica têm sido reconhecidos no leste de Rondônia -Suíte Serra da Providência (Bettencourt et al 1999, Payolla et al 2002, em Roraima a sudoeste de Boa Vista -Suíte Serra da Prata-Mucajaí (Fraga et al 2003) e no sudoeste do Amazonas -Batólito Igarapé Preto e São Francisco (Abdallah 2008). Granitos rapaviki de idade mais antiga, entre 1.80 e 1.88 Ga, tem sido registrados na região de Carajás -granitos Jamon e Musa, e de Pitingagranitos Madeira e Água Boa (Dall'Agnol et al 1999).…”

unclassified

“…Granitos rapaviki de idade mais antiga, entre 1.80 e 1.88 Ga, tem sido registrados na região de Carajás -granitos Jamon e Musa, e de Pitingagranitos Madeira e Água Boa (Dall'Agnol et al 1999). Tí-picas associações incluindo termos anortosíticos -AMCG -são por outro lado mais raros sendo, no entanto, reconhecido o Complexo AMG Mucajaí (Fraga et al 2003(Fraga et al e 2009, onde prescinde o termo charnockítico.…”

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Suíte Rio do Sangue: registro de uma associação AMCG no sudoeste do Cráton Amazônico, noroeste do estado de Mato Grosso

Leite¹,

Sousa²,

Batata³

et al. 2010

RBG

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Resumo A Suíte Rio do Sangue (SRS) localiza-se na porção sudoeste do Cráton Amazônico, nos domínios da Província Rio Negro-Juruena ou Rondônia-Juruena, noroeste do estado de Mato Grosso. Ocorre sob a forma de um cinturão alongado de direção E-W, com aproximadamente 400 km de comprimento, que se estende desde as proximidades de Tabaporã até o oeste do município de Juína na divisa entre Mato Grosso e Rondônia. Esta suíte compõe-se pelas unidades Granito Fontanillas, Anortosito Castanheira, Charnockito-Mangerito São Roque, Granito Juara e Gabro Juína; o Granito Fontanillas é o termo rapakivítico da suíte. Os dados geocronológicos apontam para um intervalo de tempo de 7 Ma para sua formação, entre 1.54 e 1.47 Ga, o que é aproximadamente 230 Ma mais novo que o último evento colisional até então reconhecido na região (1.8-1.75 Ga). A assinatura isotópica de Nd mostra valores de εNd entre -2 e -6 com T Dm entre 2.35 Ga e 2.5 Ga. Baseado nas principais características da SRS é aqui sugerida sua correlação com as associações do tipo AMCG (anortositos, mangeritos, charnockitos e granitos rapakivi) mundialmente reconhecidas durante o Mesoproterozóico e tidas como oriundas de processos de fragmentação do Super-continente Colúmbia. Entre 1.47 e 1.4 Ga a SRS foi submetida a um importante evento metamórfico deformacional em condições de fácies anfibolito, responsável pela formação de corredores E-W de milonitos e augen-gnaisses. Finalmente, uma correlação com o magmatismo anorogênico do leste da Rondônia é proposta, dada as similaridades composicionais e de idades entre a SRS e a Suíte Serra da Providência.Palavras-chave: AMCG, Suíte Rio do Sangue, Cráton Amazônico, Supercontinente, Columbia. Abstract Rio do Sangue Suite: register of an AMCG suite in southwest of the Amazonia Cráton -northwest of the Mato Grosso state. The Rio do Sangue Suite (SRS) is located in the Southwest portion of AmazonianCraton, within the realm of the Rio Negro-Juruena Province or Rondônia-Juruena Province (1.85-1.75 Ga), extending over a E-W trending belt up to 400 km long in northwest of Mato Grosso State. This suite consists of five units namely: Fontanillas Granite, Castanheira Anortosite, São Roque Charnockite-Mangerite, Juara Granite and Juína Gabbro. The Fontanillas Granite is dominantly rapakivi-textured. Geochronologic data points to a 7 Ma interval for its formation between 1.54 and 1.47 Ga. The Nd isotopic signature is marked by End values between -2 to -6. with TDM between 2.35 and 2.5 Ga. The SRS evolved nearly 230 Ma after the main collision peak Based on its main characteristics the SRS is here correlated to the well-known anorogenic AMCG suites which are globally distributed, especially during the Mesoproterozoic times and which are thought to have been evolved during extensional tectonic phases associated to the fragmentation of the Super-continent Columbia.. Between 1.47 and 1.40 Ga the SRS is overprinted by tectono-metamorphic event in amphibolite facies conditions which generated an E-W trending belt of mylonite and augen gnaisses....

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The Roraima Alkaline Province: A cretaceous alkaline province in the Amazonian Craton

2022

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The Mesoproterozoic Mucajai Anorthosite - Mangerite - Rapakivi Granite Complex, Amazonian Craton, Brazil

Cited by 28 publications

References 51 publications

K'Mudku A-type magmatism in the southernmost Guyana Shield, central-north Amazon Craton (Brazil): the case of Pedra do Gavião syenogranite

K'Mudku A-type magmatism in the southernmost Guyana Shield, central-north Amazon Craton (Brazil): the case of Pedra do Gavião syenogranite

Suíte Rio do Sangue: registro de uma associação AMCG no sudoeste do Cráton Amazônico, noroeste do estado de Mato Grosso

The Roraima Alkaline Province: A cretaceous alkaline province in the Amazonian Craton

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