Geology and Lithogeochemistry of the Supracrustal Sequence and Interlayered Metabasites of NE Santos Dumont Region (MG)

Authors

  • Renata Hiraga Centro de Tecnologia Mineral, Av. Pedro Calmon, 900, 21941-908, Cidade Universitária, Rio de Janeiro, RJ, Brasil. Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Departamento de Geologia Regional e Geotectônica, Rua São Francisco Xavier, 524, sala 4006, 20550-900, Maracanã, Rio de Janeiro, RJ, Brasil.
  • José Renato Nogueira Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Departamento de Geologia Regional e Geotectônica, Rua São Francisco Xavier, 524, sala 4006, 20550-900, Maracanã, Rio de Janeiro, RJ, Brasil.
  • Beatriz Paschoal Duarte Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Departamento de Geologia Regional e Geotectônica, Rua São Francisco Xavier, 524, sala 4006, 20550-900, Maracanã, Rio de Janeiro, RJ, Brasil.
  • Claudia Sayão Valladares Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Departamento de Geologia Regional e Geotectônica, Rua São Francisco Xavier, 524, sala 4006, 20550-900, Maracanã, Rio de Janeiro, RJ, Brasil.
  • Vinicius de Oliveira Monteiro Guimarães Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Departamento de Geologia Regional e Geotectônica, Rua São Francisco Xavier, 524, sala 4006, 20550-900, Maracanã, Rio de Janeiro, RJ, Brasil.
  • Rodrigo Peternel Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Departamento de Geologia Regional e Geotectônica, Rua São Francisco Xavier, 524, sala 4006, 20550-900, Maracanã, Rio de Janeiro, RJ, Brasil.

DOI:

https://doi.org/10.11137/2017_3_359_376

Keywords:

Lithogeochemistry, Geology, Metabasites, Supracrustal sequence

Abstract

The region near Santos Dumont town consists of a sequence of interlayered metabasic rocks and supracrustal gneisses. Two lithological units were individualized based on geological-structural mapping (1:50,000), petrography and lithogeochemistry: a metasedimentary sequence interlayered with metavolcanic rocks (Conceição do Formoso Group), and a group of metabasic rocks (Oliveira Fortes Unit). The metavolcanic sequence is represented by gneisses of dacitic and riolitic compositions, with calc-alkaline affinity and weak peraluminous character, suggesting that the original magma was contaminated by crustal component. These gneisses have a geochemical signature of a destructive margin environment and their origin can be related to volcanic arc magmatism. The metabasic rocks present geochemical signature of intraplate tholeiitic basalts and are interpreted as sills interlayered within the metavolcanosedimentary sequence.

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Published

2019-07-30

Issue

Vol. 40 No. 3 (2017)

Section

Article

License

This journal is licensed under a Creative Commons — Attribution 4.0 International — CC BY 4.0, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.