The Archean–Paleoproterozoic evolution of the Quadrilátero Ferrífero (Brasil): Current models and open questions

Farina, F. and Albert, Capucine and Martínez Dopico, C. and Aguilar Gil, C. and Moreira, H. and Hippertt, J.P. and Cutts, K. and Alkmim, F.F. and Lana, C. (2016) The Archean–Paleoproterozoic evolution of the Quadrilátero Ferrífero (Brasil): Current models and open questions. Journal of South American Earth Sciences, 68. pp. 4-21. ISSN 0895-9811 DOI https://doi.org/10.1016/j.jsames.2015.10.015

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Official URL: https://doi.org/10.1016/j.jsames.2015.10.015

Abstract

The Quadrilátero Ferrífero is a metallogenic district (Au, Fe, Mn) located at the southernmost end of the São Francisco craton in eastern Brazil. In this region, a supracrustal assemblage composed of Archean greenstone and overlying Neoarchean–Paleoproterozoic sedimentary rocks occur in elongated keels bordering domal bodies of Archean gneisses and granites. The tectonomagmatic evolution of the Quadrilàtero Ferrífero began in the Paleoarchean with the formation of continental crust between 3500 and 3200 Ma. Although this crust is today poorly preserved, its existence is attested to by the occurrence of detrital zircon crystals with Paleoarchean age in the supracrustal rocks. Most of the crystalline basement, which is composed of banded gneisses intruded by leucogranitic dikes and weakly foliated granites, formed during three major magmatic events: Rio das Velhas I (2920–2850 Ma), Rio das Velhas II (2800–2760 Ma) and Mamona (2760–2680 Ma). The Rio das Velhas II and Mamona events represent a subduction-collision cycle, probably marking the appearance of a modern-style plate tectonic regime in the Quadrilátero Ferrífero. Granitic rocks emplaced during the Rio das Velhas I and II events formed by mixing between a magma generated by partial melting of metamafic rocks with an end member derived by recycling gneissic rocks of older continental crust. After deformation and regional metamorphism at ca. 2770 Ma, a change in the composition of the granitic magmas occurred and large volumes of high-K granitoids were generated.

Item Type: Article
Uncontrolled Keywords: NILAREP
Subjects: 05 - Petrology - Igneous, Metamorphic and Volcanic Studies
Divisions: 05 - Petrology - Igneous, Metamorphic and Volcanic Studies
Journal or Publication Title: Journal of South American Earth Sciences
Volume: 68
Page Range: pp. 4-21
Identification Number: https://doi.org/10.1016/j.jsames.2015.10.015
Depositing User: Sarah Humbert
Date Deposited: 22 May 2019 17:25
Last Modified: 22 May 2019 17:25
URI: http://eprints.esc.cam.ac.uk/id/eprint/4497

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