Please use this identifier to cite or link to this item: http://www.repositorio.ufop.br/jspui/handle/123456789/13604
Title: High-K granites between the Archean Gavião and Jequié blocks, São Francisco craton, Brazil : implications for cratonization and amalgamation of the Rhyacian Atlantica continent.
Authors: Zincone, Stéfano Albino
Oliveira, Elson Paiva de
Ribeiro, Bruno Pinto
Marinho, Moacyr Moura
Keywords: Neoarchean high-K granitic magmatism
Strike-slip at plate boundary
Rhyacian atlantic continent
Issue Date: 2021
Citation: ZINCONE, S. A. et al. High-K granites between the Archean Gavião and Jequié blocks, São Francisco craton, Brazil: implications for cratonization and amalgamation of the Rhyacian Atlantica continent. Journal of South American Earth Sciences, v. 105, p. 102920, jan. 2021. Disponível em: <https://www.sciencedirect.com/science/article/abs/pii/S0895981120304636>. Acesso em: 24 mar. 2021.
Abstract: Precambrian terrane boundaries are sites of diverse rock associations and structural complexity. Motions along the boundary zones are commonly related to the construction of ancient large continental masses. This seems to be the case in the Sao ˜ Francisco Craton, Brazil, where three major blocks (Gavião, Jequié and Serrinha) collided in the Paleoproterozoic to form the northern part of the craton. This manuscript presents zircon U-Pb ages and whole-rock geochemistry for rock associations on the western border of the Jequié Block, which is defined by the north-trending left-lateral 600-km long Contendas-Jacobina fault zone. The studied rocks are granulite to amphibolite facies Neoarchean orthopyroxene-hornblende granite gneisses of the Jequié block, which also occur tectonically imbricated within Paleoproterozoic metavolcanosedimentary rocks of the Contendas-Mirante belt. The rocks are 2.65-2.63 Ga high-K ferroan, metaluminous to slightly peraluminous syeno-monzogranite in composition, with negative ƐNd (2650) and Nd model ages of 3.05-2.88 Ga. They are depleted in Sr and Ti, enriched in Th, Ba and Pb enrichment, and have marked negative Eu/Eu*. This geochemical signature coupled with the Nd-isotope data indicate that the parental granitic magma was generated by crustal reworking of felsic Mesoarchean crust distinct from the western-sitting >3.3 Ga Gavião Block. The investigated granitic gneisses are similar to other potassic granitoids that occur in the São Francisco Craton, which mark the thermal stabilization of the Archean lithosphere. The westward thrusting of the Neoarchean hornblende granitic gneiss and associated high-Mg tremolitite (meta-basalts) onto Paleoproterozoic volcano-sedimentary sequences establishes field evidence of Paleoproterozoic nappe stacking before lateral displacement during block collision. The crustal amalgamation is related to the assembly of the São Francisco-Congo Craton, a major landmass established before the Columbia supercontinent.
URI: http://www.repositorio.ufop.br/jspui/handle/123456789/13604
metadata.dc.identifier.uri2: https://www.sciencedirect.com/science/article/abs/pii/S0895981120304636
metadata.dc.identifier.doi: https://doi.org/10.1016/j.jsames.2020.102920
ISSN: 0895-9811
Appears in Collections:DEGEO - Artigos publicados em periódicos

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