PRELIMINARY REPORT ON THE LACUSTRINE STRATA OF THE SANFRANCISCANA BASIN IN NORTHERN MINAS GERAIS, BRAZIL

  • Jonathas S. Bittencourt Laboratório de Paleontologia e Macroevolução, Centro de Pesquisas Professor Manoel Teixeira da Costa, Instituto de Geociências, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil.
  • Pedro L. C. R. Vieira Instituto de Geociências, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil.
  • Raphael M. Horta Laboratório de Paleontologia e Macroevolução, Centro de Pesquisas Professor Manoel Teixeira da Costa, Instituto de Geociências, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil.
  • André G. Vasconcelos Laboratório de Paleontologia e Macroevolução, Centro de Pesquisas Professor Manoel Teixeira da Costa, Instituto de Geociências, Universidade Federal de Minas Gerais. Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil. 
  • Natália C. A. Brandão Laboratório de Paleontologia e Macroevolução, Centro de Pesquisas Professor Manoel Teixeira da Costa, Instituto de Geociências, UFMG. Programa de Pós-graduação em Zoologia, Instituto de Ciências Biológicas, UFMG.
  • Angelo Dos Santos Department of Earth and Planetary Sciences, McGill University, Montréal, Quebec H3A 0E8, Canada.
  • Luiz Guilherme Knauer Instituto de Geociências, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil.

Abstract

We report new data on the geology and the fossil record of the Sanfranciscana Basin in sites to the north of the traditionally explored localities within Minas Gerais. The strata in the new explored area are formed by distinct lithologies, encompassing pelitic rocks with caliche levels and metric bodies of cross-bedded sandstone towards the top, similar to the fluviolacustrine beds of the Areado Group in the southern portions of the basin. Also similar to other regions of the São Francisco Craton, the deposits of the Sanfranciscana Basin studied herein lie discordantly to the rocks of the Bambuí Basin. We preliminarily report neopterygian fish scales, little informative archosaurian bones and an association of the ostracods Ilyocypris- Fossocytheridea. This ostracod association is registered for the first time in the Cretaceous of the Sanfranciscana Basin. The ostracods have been collected from the lacustrine, vertebrate-bearing rocks cropping out in Lagoa dos Patos and Coração de Jesus. The cytherideid Fossocytheridea assigns a minimal Aptian age to its bearing rocks. Its association with Ilyocypris was also reported in Upper Cretaceous oligohaline paleoenvironments in Brazil and Argentina, indicating similar depositional conditions to the strata reported in this paper. The putative affinities of the specimens of the Sanfranciscana Basin with F. ventrotuberculata, and their association with Ilyocypris, raise the hypothesis of a younger age for some levels of that basin in northern Minas Gerais, perhaps ranging into the Late Cretaceous.

Keywords: Ostracoda, Archosauria, Areado Group, Cretaceous, Gondwana

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Published
2020-01-31
Section
Artigos