SciELO - Scientific Electronic Library Online

 
vol.47 número3Basaltos pós-colisionais da Formação Acampamento Velho, Bacia do Camaquã, Terreno São Gabriel, sul do BrasilVariações isotópicas de C, O e Sr em rochas carbonáticas do Neoproterozoico-Cambriano da Formação Sete Lagoas (Grupo Bambuí), no Sul da Bacia do São Francisco, Brasil índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

Compartilhar


Brazilian Journal of Geology

versão impressa ISSN 2317-4889versão On-line ISSN 2317-4692

Resumo

COSTA, Alice Fernanda  e  DANDERFER FILHO, André. Tectonics and sedimentation of the central sector of the Santo Onofre rift, north Minas Gerais, Brazil. Braz. J. Geol. [online]. 2017, vol.47, n.3, pp.491-519.  Epub 21-Set-2017. ISSN 2317-4889.  http://dx.doi.org/10.1590/2317-4889201720160128.

The Santo Onofre Group registers the filling of a Tonian, intracontinental paleo-rift that developed along the northern and central Espinhaço regions. This paper examines this unit in the central Espinhaço region with stratigraphic analysis and U-Pb geochronology, reviewing and dividing into the Canatiba and Rio Peixe Bravo Formations, which include the Barrinha Member. The Canatiba Formation mainly comprises carbon-rich mudstones that were deposited through low-density turbidity flows that alternated with sediment settling under anoxic conditions. The Rio Peixe Bravo Formation consists of a succession of sandstones and minor mudstones, which were deposited through low- to high-density turbidity flows. The Barrinha Member mainly consists of conglomerates and is related to channelized debris flows. Detrital zircon grains show maximum depositional ages of 930 ± 33 Ma and around 865 Ma for the Canatiba and Rio Peixe Bravo Formations, respectively. We interpret the Santo Onofre rifting to be relative younger than that for the Sítio Novo Group and to be a precursor stage of the glacial and post-glacial rift-to-passive margin-related sequences of the Macaúbas Group. The lithostratigraphic term “Macaúbas Supergroup” would be of better use to accommodate the unconformity-bounded Tonian sequences that were related to the Rodinia breakup in the Congo-São Francisco paleocontinent.

Palavras-chave : Rodinia supercontinent; Santo Onofre rift; Tonian; Macaúbas basin.

        · resumo em Português     · texto em Inglês     · Inglês ( pdf )