Idades U-Pb (Zircões) de 1.75 Ga em granitóides alcalinos deformados dos núcleos Betara e Tigre: evidências de regimes extensionais do estateriano na Faixa Apiaí

Authors

  • Leonardo Fadel Cury Universidade de São Paulo; Instituto de Geociências; Programa de Pós-Graduação em Geoquímica e Geotectônica
  • Gilberto Alexander Kaulfuss Universidade de São Paulo; Instituto de Geociências; Programa de Pós-Graduação em Geoquímica e Geotectônica
  • Oswaldo Siga Jr. Universidade de São Paulo; Instituto de Geociências; Departamento de Mineralogia e Geotectônica
  • Miguel Angelo Stipp Basei Universidade de São Paulo; Instituto de Geociências; Departamento de Mineralogia e Geotectônica
  • Ossama Mohamed Harara Universidade de São Paulo; Instituto de Geociências; Programa de Pós-Graduação em Geoquímica e Geotectônica
  • Kei Sato Universidade de São Paulo; Instituto de Geociências; Centro de Pesquisas Geocronológicas

DOI:

https://doi.org/10.5327/S1519-874X2002000100009

Keywords:

alkaline granitoids, U-Pb (zircon), Statherian Period, extensional processes

Abstract

Geochronological study of deformed alkaline rocks belonging to the NE-SW oriented ellipsoidal Betara and Tigre basement nuclei, located in the midst of metavolcanossedimentary rocks of the Apiaí Belt provide new data on superimposed tectonic events of regions complex geological history. Protomylonitic, mylonitic and ultramylonitic syenogranites predominate and exhibit lithogeochemical characters of anorogenic 'A' type granites. U-Pb (zircon) dating indicates Paleoproterozoic ages of 1748 ± 5.4 Ma in the Betara Nuclei and 1772 ± 9.5 Ma in the Tigre Nuclei. These Statherian ages represent an important regional benchmark. Ages between 1600 Ma and 1800 Ma, predominantly associated with extensional processes, are recognized mainly in the eastern-central portion of the South American continent where they are interpreted as representing the age of rupture of the Paleoproterozoic Atlantic Supercontinent.

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Published

2002-12-01

Issue

Vol. 2 (2002)

Section

Articles

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How to Cite

Cury, L. F., Kaulfuss, G. A., Siga Jr., O., Basei, M. A. S., Harara, O. M., & Sato, K. (2002). Idades U-Pb (Zircões) de 1.75 Ga em granitóides alcalinos deformados dos núcleos Betara e Tigre: evidências de regimes extensionais do estateriano na Faixa Apiaí . Geologia USP. Série Científica, 2, 95-108. https://doi.org/10.5327/S1519-874X2002000100009