3.65–2.10Ga history of crust formation from zircon geochronology and isotope geochemistry of the Quijingue and Euclides plutons, Serrinha nucleus, Brazil

Evolução crustal do setor ocidental do Bloco Arqueano Gavião, Cráton do São Francisco, com base em evidências U-Pb, Sm-Nd e Rb-Sr

“…No Estado da Bahia, a crosta primitiva foi edificada por meio de vários processos orogenéticos, com destaque para a geração de associações granito-greenstone e terrenos metamórficos de médio a alto grau (Barbosa e Sabaté, 2004;Barbosa et al, 2012). De acordo com o acervo de dados U-Pb, Sm-Nd e Rb-Sr, os eventos orogenéticos mais primitivos identificados regionalmente podem ser sumarizados como segue: domínios crustais distintos com idades do Paleoarqueano (3,6 -3,2 Ga), com greenstone belts (3,3 -3,0 Ga) e rochas granitoides de composição TTG (tonalito-trondjemito-granodiorito) com idades entre 3,2 e 2,9 Ga (Martin et al, 1997;Rios et al, 2008Rios et al, , 2009Dantas et al, 2010;Oliveira et al, 2010;Teixeira et al, 2010).…”

Mesoarchaean to Palaeoproterozoic growth of the northern segment of the Itabuna–Salvador–Curaçá orogen, São Francisco craton, Brazil

“…The oldest rocks so far recognized are 3.4 Ga grey gneisses in the Gavião block of the São Francisco craton (Martin et al 1991(Martin et al , 1997Nutman & Cordani 1993) and 3.5 Ga migmatite inliers within Neoproterozoic gneisses of northeastern Brazil (Dantas et al 2004). Indications of much older crust have come recently from 3.8 Ga detrital zircons in quartzites of the Iron Quadrangle in Minas Gerais state (Hartmann et al 2006) and as 3.6 Ga zircon xenocrysts in granites of the São Francisco craton (Rios et al 2008). However, extensive belts of Palaeoarchaean to Palaeoproterozoic crust are well exposed in the northeastern part of the São Francisco craton, and they may provide insights into how continental crust evolved during a time of profound changes in planet Earth.…”

Geochronology of granulites from the south Itabuna-Salvador-Curaçá Block, São Francisco Craton (Brazil): Nd isotopes and U–Pb zircon ages

“…collision is not only recorded in the structural features, but also in the pre-and syntectonic Palaeoproterozoic rocks that are intruded into these crustal segments, mainly in the Gavião Block (Marinho, 1991;Santos Pinto et al, 1998;Bastos Leal, 2003), the ItabunaSalvador-Curaçá Block (Ledru et al, 1994;Barbosa and Sabaté, 2004) and the Serrinha Block (Oliveira et al, 1999(Oliveira et al, , 2002Melo et al, 2000;Rios et al, 2005Rios et al, , 2008Rios et al, , 2009. During the collision, slices of the Jequié Block may have been incorporated into the Itabuna-Salvador-Curaçá Block.…”

“…1) crops out at the north-eastern extremity of the São Francisco Craton. It is composed of tonalitic, granodioritic Archaean orthogneisses whose ages range from 3.1 to 2.8 Ga (Cordani et al, 1999;Oliveira et al, 1999Oliveira et al, , 2002Melo et al, 2000;Rios et al, 2005Rios et al, , 2008Rios et al, , 2009. Palaeoproterozoic calc-alkaline plutons were emplaced at ca 2.15 Ga and alkaline suites ca 2.10 Ga, (Rios et al, 2008(Rios et al, , 2009.…”

“…It is composed of tonalitic, granodioritic Archaean orthogneisses whose ages range from 3.1 to 2.8 Ga (Cordani et al, 1999;Oliveira et al, 1999Oliveira et al, , 2002Melo et al, 2000;Rios et al, 2005Rios et al, , 2008Rios et al, , 2009. Palaeoproterozoic calc-alkaline plutons were emplaced at ca 2.15 Ga and alkaline suites ca 2.10 Ga, (Rios et al, 2008(Rios et al, , 2009. Rios et al, (2008) indicate the occurence of 3.6 Ga zircon xenocrysts in a 2.16 Ga trondhjemite.The 2.15e2.12 Ga old Rio Itapicuru and Rio Capim greenstone belts (Silva, 1996;Oliveira et al, 2011) overlie the basement and are intruded by a wide variety of granites (Alves da Silva, 1994) with ages between 2.10 and 2.07 Ga (Rios et al, 2005(Rios et al, , 2008Oliveira et al, 2011).…”