The ArcheanePaleoproterozoic evolution of the Quadril  atero Ferrífero (Brasil): Current models and open questions F. Farina * , C. Albert, C. Martínez Dopico, C. Aguilar Gil, H. Moreira, J.P. Hippertt, K. Cutts, F.F. Alkmim, C. Lana Departamento de Geologia, Universidade Federal de Ouro Preto, Morro do Cruzeiro, 35400-000 Ouro Preto, MG, Brazil article info Article history: Received 29 June 2015 Received in revised form 30 September 2015 Accepted 27 October 2015 Available online xxx Keywords: Quadril atero Ferrífero Archean Paleoproterozoic Tectonomagmatic evolution S~ ao Francisco craton abstract The Quadril atero Ferrífero is a metallogenic district (Au, Fe, Mn) located at the southernmost end of the S~ ao Francisco craton in eastern Brazil. In this region, a supracrustal assemblage composed of Archean greenstone and overlying NeoarcheanePaleoproterozoic sedimentary rocks occur in elongated keels bordering domal bodies of Archean gneisses and granites. The tectonomagmatic evolution of the Quadril atero 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 (2920e2850 Ma), Rio das Velhas II (2800e2760 Ma) and Mamona (2760e2680 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 Quadril atero 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. The ca. 6000 m-thick Minas Supergroup tracks the opening and closure of a basin during the Neo- archeanePaleoproterozoic, between 2600 and 2000 Ma. The basal sequence involves continental to marine sediments deposited in a passive margin basin and contain as a marker bed the Lake Superior- type Cau^ e Banded Iron Formation. The overlying sediments of the Sabar a Group mark the inversion of the basin during the Rhyacian Minas accretionary orogeny. This orogeny results from the collision be- tween the nuclei of the present-day S~ ao Francisco and Congo cratons, generated the fold-and thrust belt structure of the Quadril atero Ferrífero. Afterwards, the post- orogenic collapse resulted in the deposition of the Itacolomi Group and in the genesis of the dome-and-keel structure. In this paper, we review current knowledge about the 1500 Ma long-lasting tectonomagmatic and structural evolution of the Quadril atero Ferrífero identifying the most compelling open questions and future challenges. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction In the mid-twentieth century, the ca. 7000 km 2 portion of the Brazilian highlands south of the city of Belo Horizonte (Fig. 1) became well-known under the name of Quadril atero Ferrífero (“Iron Quadrangle”). This region, which has been an important mining site since the XVII century, represents the most intensively studied region of Brazil. Its valuable iron deposits together with its puzzling geological complexity have attracted the attention of many scientists over the last century. The goal of the present paper is to provide an up-to-date state of the art about the geology of the Archean crystalline basement and ArcheanePaleoproterozoic metasedimentary sequences forming the Quadril atero Ferrífero. This review, focussed on the Archean and Paleoproterozoic * Corresponding author. E-mail address: fannak@gmail.com (F. Farina). Contents lists available at ScienceDirect Journal of South American Earth Sciences journal homepage: www.elsevier.com/locate/jsames http://dx.doi.org/10.1016/j.jsames.2015.10.015 0895-9811/© 2015 Elsevier Ltd. All rights reserved. Journal of South American Earth Sciences xxx (2015) 1e18 Please cite this article in press as: Farina, F., et al., The ArcheanePaleoproterozoic evolution of the Quadril atero Ferrífero (Brasil): Current models and open questions, Journal of South American Earth Sciences (2015), http://dx.doi.org/10.1016/j.jsames.2015.10.015