Eoarchean to Mesoarchean crustal evolution of the northern São Francisco Craton, Brazil: geochronological and isotopic perspectives. Rafael GORDILHO BARBOSA1, Rommulo V. CONCEIÇÃO1, Felipe P. LEITZKE1, Johildo S.F. BARBOSA2, Jonas TUSCH3, Carsten MÜNKER3,Alanielson C.D. FERREIRA4 1 Institute of Geosciences, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre, RS, Brazil. 2 Basic Geology Nucleus, Federal University of Bahia, Rua Barão de Jeremoabo, s/n, Ondina, Salvador, BA, Brazil.
[email protected] 3 Institut für Geologie und Mineralogie, Universität zu Köln, Zülpicher Straβe 49b, 50674 Cologne, Germany 4 Department of Earth Sciences, Stellenbosch University, Private Bag X1, Matieland, 7602, Stellenbosch, South Africa INTRODUCTION STUDY AREA The Earth’s oldest cratons represent the relicts of Eoarchean to Paleoarchean continental crust formed by The research was focused on the northern part of the SFC, specifically in the areas where Eo-to- tonalite-trondhjemite-granodiorite (TTG) rocks associated with Na-rich granitic leucosome. In this context, Mesoarchean rocks outcrop, i.e: the major question is what the sources and available heat at that time are and, more importantly, how did the ▪ Gavião Block (GB) – It represents most of the northern SFC. Three generations of TTGs occur in the GB early-Earth tectonic processes and the crust generation operate in Hadean/Eo-to-Mesoarchean times. with U-Pb ages of 3642-3529 Ma (Oliveira et al., 2020), 3403-3378 Ma (Bastos Leal et al., 2003) and 3259- In South America, the São Francisco Craton (SFC) is one of the most representative cratonic areas and 3240 Ma (Santos Pinto et al., 2012).