Geochemistry of two proterozoic A-type granites of Goias state, Brazil: possible links with rapakivi series
Résumé
The Mesoproterozoic (1.77 ga-1.60 ga) granites of the Goias Tin Province occur in the states of Goias and Tocantins, Brazil. They are situated in the Rio Parana and the Rio Tocantins sub-provinces. They are very similar in mineralogy, geochemistry, and age of emplacement, to the Arai rhyolites. Their compositions are comparable to those of A-type granites. The present paper discusses the principal mineralogical and geochemical characteristics of the Sucuri and Serra Dourada granites of the Goias tin-province.