Evidence for a complex accretionary history preceding the amalgamation of Columbia: The Rhyacian Minas-Bahia Orogen, southern São Francisco Paleocontinent, Brazil

The role of V-shaped oceans and ribbon continents in the Brasiliano/PanAfrican assembly of western Gondwana

“… Regionally extensive Rhyacian-Orosirian orogenic belts with mean peak of activity in the 2.2–1.9 Ga age range. This is the so-called “Transamazonian” or Minas-Bahia Orogeny of the Mineiro and Itabuna-Salvador-Curaçá belts within the São Francisco craton domain 42 , 57 , 58 , and is indeed the main episode of crust formation in the São Francisco-Congo, Borborema/NW Africa, Tocantins and Mantiqueira/SW Africa provinces, readily recognizable in igneous zircon U–Pb age distribution plots (Fig. 2 ).…”

Rhyacian magmatic arc rocks with sanukitoid geochemical signature from the Juiz de Fora Complex, Minas-Bahia Orogenic System (SE-Brazil)

“…In the southernmost sector of the São Francisco Paleocontinent, Archean blocks are bounded by Siderian-Rhyacian-Orosirian orogenic belts in the Minas Segment of the MBOS (Ávila et al 2010, Seixas et al 2013, Alkmim and Teixeira 2017, Moreira et al 2018, Bruno et al 2020, 2021a, 2021b. The Archean exposures are represented by greenstone belt remnants (Pimhuí, Rio das Velhas, and Pitangui) and several metamorphic complexes (e.g., Bonfim, Belo Horizonte, Campo Belo, and Piedade complexes) comprising gneisses, migmatites, and granitoid rocks.…”

“…The Archean exposures are represented by greenstone belt remnants (Pimhuí, Rio das Velhas, and Pitangui) and several metamorphic complexes (e.g., Bonfim, Belo Horizonte, Campo Belo, and Piedade complexes) comprising gneisses, migmatites, and granitoid rocks. These crustal complexes/ blocks acquired stability by the late-Neoarchean, establishing the core of the São Francisco Paleocontinent, which was further amalgamated with other Archean blocks (Piedade and others) between the Siderian and Early Orosirian, resulting in the formation of the Minas segment of the MBOS (Barbosa et al 2015, Alkmim and Teixeira 2017, Bruno et al 2020, 2021b.…”

“…In that context, these rocks have been interpreted as representing the transition from typical Archean geodynamics to Paleoproterozoic modern plate tectonics (Martin et al 2005, Heilimo et al 2010, Bruno et al 2020. Although most of the known sanukitoid suites were formed in the Neoarchean and Mesoarchean (e.g., Oliveira et al 2009, Martin et al 2010, Heilimo et al 2010, Laurent et al 2014, Sun et al 2020, Valeriano et al 2022, numerous works have characterized Proterozoic and Phanerozoic magmatic arc granitoid rocks with affinity with the sanukitoid series (e.g., Fowler and Rollinson 2012, Seixas et al 2013, Moreira et al 2018, Bruno et al 2020, 2021b, Raza et al 2021, Zhang et al 2021. Therefore, the investigation of sanukitoid rocks has direct implications for a better understanding of when and how stable and long-lived subduction settings.…”

“…The southeastern region of Brazil records a complex geotectonic evolution involving the accretion and collage of several crustal terranes/blocks during at least two orogenic events: the Paleoproterozoic of the Minas-Bahia Orogenic System (MBOS), culminating with the formation of the São Francisco Paleocontinent (Heilbron et al 2010, Alkmim and Teixeira 2017, Degler et al 2018, Bruno et al 2020, 2021a, 2021b; and the Neoproterozoic Brasiliano/Pan-African orogenies that resulted in the amalgamation of the Western Gondwana (Pedrosa-Soares et al 2001, Noce et al 2007, Tupinambá et al 2012, Heilbron et al 2017, 2020a, 2020b, Caxito et al 2022. The Brasiliano orogenic event reworked the margins of the São Francisco Paleocontinent and was responsible for the inversion of Mesoproterozoic to Neoproterozoic sedimentary basins and the generation of widespread pre-, syn-, late-, and post-collisional magmatic suites (Heilbron et al 2010(Heilbron et al , 2020a.…”