The 2.58 Ga Sao Jose do Jacuipe gabbro-anorthosite stratiform complex, Itabuna-Salvador-Curaca Orogen, Sao Francisco Craton, Brazil: Root of the Neoarchaean Caraiba continental arc?

Autor(es)

Piaia, Patricia ^[1] ; Oliveira, Elson P. ^[1] ; Valeriano, Claudio M. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Dept Geol & Nat Resources, POB 6152, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estado Rio De Janeiro, Dept Geol, Rua Sao Francisco Xavier, 524 Room 4006A, BR-20559900 Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of South American Earth Sciences; v. 79, p. 326-341, NOV 2017.
• Citações Web of Science: 3

Resumo

Mafic-ultramafic complexes are common in ancient orogenic belts and can represent arc roots, obducted ophiolite remnants, continental intrusions, subducted oceanic plateaux or lithospheric mantle fragments. The Archaean-Palaeoproterozoic Itabuna-Salvador-Curaca Orogen hosts several mafic-ultramafic complexes, whose petrogenetic understanding is difficult owing to the high-grade metamorphism and deformation. One of these complexes is the 2583.7 +/- 7.7 Ma Sao Jose do Jacuipe Gabbro-Anorthosite Complex, composed of massive to stratiform, deformed and metamorphosed anorthosites, leucogabbros, and gabbros with minor pyroxenites. Field relationships of the mafic-ultramafic rocks combined with calcic-pyroxene chemistry, negative Nb anomalies in mantle-normalised diagrams, and dominantly positive epsilon(Nd(t)) values suggest similarities with arc mafic magmatism. The gabbro-anorthosite complex matches the ages of arc orthogneisses (2574 +/- 6 Ma) and norite-hypersthenite complex (2580 +/- 10 Ma) of the Caraiba Complex and is thus interpreted as a fragment of the root of the Neoarchaean Caraiba magmatic arc within the Itabuna-Salvador-Curaca Orogen. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 12/15824-6 - Evolução de terrenos arqueanos do Cráton São Francisco e Província Borborema: implicações para processos geodinâmicos e paleoambientais globais
• Beneficiário: Elson Paiva de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Temático