PETROGRAFIA E LITOQUÍMICA DO MAGMATISMO TARDI-OROGÊNICO TOLEÍTICO ALTO-K E DA SUÍTE PÓS-COLISIONAL ALCALINA SATURADA EM SÍLICA DE GOUVEIA (MG)

Authors

  • Alexandre de Oliveira Chaves Universidade Federal de Minas Gerais
  • Raphael Martins Coelho Universidade Federal de Minas Gerais
  • Friedrich Ewald Renger Universidade Federal de Minas Gerais
  • Tania Mara Dussin Universidade Federal de Minas Gerais
  • Maria do Rosário Mascarenhas de Almeida Azevedo Universidade de Aveiro
  • Sara Monteiro Ribeiro Universidade de Aveiro

Abstract

Close to Gouveia town (MG) and located inside granitoids and gneiss of the Gouveia Complex, porphyritic latites (or trachy-andesites) slightly metamorphosed are identified, with plagioclase and sanidine phenocrysts and matrix also feldspar-rich containing biotite, magmatic epidote and quartz. Occurring adjacent to the porphyrites, metamorphosed phanerites also appear, with terms ranging from ultramelanocratic lamprophyres (rich in amphibole and phlogopite with interstitial microcline), melanocratic monzonites (or syeno-diorite with hornblende, biotite, microcline and plagioclase), mesocratic syenites up to leucocratic quartz-syenites (with microcline, biotite and quartz). Lithochemistly, porphyrites and phanerites are metaluminous rocks, however the porphyrites are subalkaline, high-K tholeiitic and tardi-orogenic, while phanerites comprise a silica-saturated alkaline shoshonitic magmatic suite, called Gouveana Suite, whose lithotypes are genetically interrelated by magmatic fractionation processes occurred during an episode of post-collisional uplift. Apparently derived from distinct mantle sources, porphyrites and phanerites should be tectonically associated to regional transcurrent faults at the end of either Transamazonic or Brasiliano Events.

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Author Biographies

Tania Mara Dussin, Universidade Federal de Minas Gerais

Instituto de Geociências

Sara Monteiro Ribeiro, Universidade de Aveiro

Departamento de Geociências

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Published

2015-02-27

How to Cite

Chaves, A. de O., Coelho, R. M., Renger, F. E., Dussin, T. M., Azevedo, M. do R. M. de A., & Ribeiro, S. M. (2015). PETROGRAFIA E LITOQUÍMICA DO MAGMATISMO TARDI-OROGÊNICO TOLEÍTICO ALTO-K E DA SUÍTE PÓS-COLISIONAL ALCALINA SATURADA EM SÍLICA DE GOUVEIA (MG). Geochimica Brasiliensis, 28(2), 117. Retrieved from https://geobrasiliensis.org.br/geobrasiliensis/article/view/393

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