Tectonic and magmatic evolution of the ribeira belt in the highlands of the Rio de Janeiro state, Brazil, from neoproterozoic to lower paleozoic

Abstract

The Highlands of the Rio de Janeiro (RSF) are composed of granitic gneiss, paragneiss and granite that are part of the Ribeira Belt. Their geological features were studied for over 50 years by authors who described orthogneisses and granites arranged in large overlapping tectonic sheaths. Tectonic domains and terranes were proposed for the Ribeira Belt, and the rocks of the RSF were included in the Oriental Terrane. The tectonic and magmatic evolution of the RSF begins in the Cryogenian with the installation of the magmatic arc of the Rio Negro Complex and sedimentation of the Italva, St. Fidélis and Bom Jesus do Itabapoana groups. During the Ediacaran collision of this arc with a passive margin the migmatitic leucogneisses of the Cordeiro Suíte were generated. At the collisional ending the calc-alkaline magmatic Serra dos Órgãos Suíte was produced. At the end of evolution, tectonic exhumation and tectonic collapse was coeval with the intrusion of Cambro-Ordovician granites of the Nova Friburgo Suíte.