ARCHEAN EVOLUTION OF THE SOUTHERN SÃO FRANCISCO CRATON (SE BRAZIL) i ii FUNDAÇÃO UNIVERSIDADE FEDERAL DE OURO PRETO Reitor Cláudia Aparecida Marliére de Lima Vice-Reitor Hermínio Arias Nalini Júnior Pró-Reitor de Pesquisa e Pós-Graduação Sérgio Francisco de Aquino ESCOLA DE MINAS Diretor Issamu Endo Vice-Diretor José Geraldo Arantes de Azevedo Brito DEPARTAMENTO DE GEOLOGIA Chefe Luis Antônio Rosa Seixas iii EVOLUÇÃO CRUSTAL E RECURSOS NATURAIS iv CONTRIBUIÇÕES ÀS CIÊNCIAS DA TERRA - VOL. 349 TESE DE DOUTORAMENTO ARCHEAN EVOLUTION OF THE SOUTHERN SÃO FRANCISCO CRATON (SE BRAZIL) Capucine Albert Orientador Dr. Cristiano de Carvalho Lana Co-orientador Dr. Federico Farina Tese apresentada ao Programa de Pós-Graduação em Evolução Crustal e Recursos Naturais do Departamento de Geologia da Escola de Minas da Universidade Federal de Ouro Preto como requisito parcial à obtenção do Título de Doutor, Área de Concentração: Tectônica, Petrogênese e Recursos Minerais OURO PRETO 2017 v vii viii Acknowledgements Many people have contributed toward the realization of this project, bringing their geological knowledge, financial or logistic support and moral encouragements, and I have every person to acknowledge and thank for their contribution, whether small or big. Thank you! Cristiano, I am indebted to you for providing me with the opportunity to do research, and for all your support throughout the years. I am particularly grateful for your enthusiasm, your trust, and your availability. Thank you for the time and effort you dedicate to your students, providing us with the opportunity to be involved in scientific discussions, and for letting us follow our own research interests and ideas. I feel truly privileged to have been a part of the dynamic group you have built, and to have had you as a mentor. Federico, your patience and your advices as I was taking my first steps into the world of research have really been priceless. Thank you for your support, your friendship, all the good laughs, and for your blunt honesty, which has me question and improve myself every time. I would like to acknowledge all those who, by sharing their knowledge have contributed one way or another to this project. I want to give a special mention to Craig Storey and Axel Gerdes, for your valuable collaboration and the stimulating discussions every time our paths have crossed. Thanks to the both of you, as well as Márcio Pimentel and Ricardo Scholz for having accepted to read and evaluate this work. I would like to extend my thanks to Gary Stevens, Jean-François Moyen, Fernando Alkmim and Ian Buick, with whom I have had the chance to discuss and exchange ideas on a regular basis. I am grateful to all the people I have met during these four years, who have enriched my life and experience in the lab and outside, I couldn‘t have done it without all of you. Special mention to G and Cynthia, for all the adventures and travels, the laughter, the encouragements and your friendship, see you soon! To all my fellow officemates, Francesco, Mari, Fabiana, Marcha and Kai, and all the others, part of the group in Ouro Preto, Hugo Boss, Dr. C, Leo, Carmen 1, Carmen 2, Ana, Lorena, Jessica and many others, as well as Camille et Julien (alias Gulen) sur la fin. You guys rock! Thanks to all the crew in Stellenbosch, Shawn Kittchy, Tolene, Stephan the Red, Duncan, Andrea, Simon, Marcos and Valby, for all the wine and the good times (Ons gaan nou braai!). And finally, last but not least, Matzi, I am so lucky to have you by my side. Mum and Dad, thank you for your unfailing support before and during my PhD, for cultivating our curiosity, and for letting us pursue what we are passionate about. ix x Summary ACKNOWLEDGEMENTS ................................................................................................................ IX SUMMARY ......................................................................................................................................... XI LIST OF FIGURES ........................................................................................................................... XV LIST OF TABLES .......................................................................................................................... XVII ABSTRACT ...................................................................................................................................... XIX RESUMO .......................................................................................................................................... XXI CHAPTER 1 - INTRODUCTION ....................................................................................................... 1 1.1 GENERAL INTRODUCTION ........................................................................................... 1 1.2 THE SECULAR EVOLUTION OF THE CONTINENTAL CRUST ................................. 5 1.2.1 Crustal growth ........................................................................................................ 5 1.2.2 Geodynamic evolution .......................................................................................... 10 1.3 ARCHEAN CRATONS ................................................................................................... 15 1.3.1 Archean granitoids ................................................................................................ 15 1.3.2 Greenstone belts.................................................................................................... 24 1.3.3 Architecture of Archean granite-greenstone terranes ........................................... 26 1.4 CONCLUSIONS .............................................................................................................. 28 CHAPTER 2 - THE ARCHEAN-PALEOPROTEROZOIC EVOLUTION OF THE QUADRILÁTERO FERRÍFERO (BRAZIL): CURRENT MODELS AND OPEN QUESTIONS ............................................................................................................................................................... 31 ABSTRACT ................................................................................................................................ 31 2.1 INTRODUCTION ............................................................................................................ 32 2.2 HISTORICAL BACKGROUND AND GEOGRAPHIC BOUNDARIES ....................... 32 2.3 MAIN GEOLOGICAL FEATURES ................................................................................ 34 2.4 THE ARCHEAN METAMORPHIC COMPLEXES ........................................................ 36 2.4.1 Field relationships and petrography ...................................................................... 36 2.4.2 Geochemistry: medium- and high-K granitoids ................................................... 38 2.4.3 Geochronology ..................................................................................................... 41 2.5 THE RIO DAS VELHAS SUPERGROUP ....................................................................... 43 2.5.1 Stratigraphy........................................................................................................... 43 2.5.2 Geochronology ..................................................................................................... 45 2.6 THE MINAS SUPERGROUP .......................................................................................... 47 2.6.1 Main stratigraphic features ................................................................................... 47 2.6.2 Tamanduá and Caraça Groups .............................................................................. 47 2.6.3 Itabira Group ......................................................................................................... 49 2.6.4 Piracicaba Group .................................................................................................. 50 2.6.5 Sabará Group ........................................................................................................ 50 2.7 THE ITACOLOMI GROUP ............................................................................................. 53 xi 2.8 MAFIC AND INTERMEDIATE DIKES, BOUDINS AND LENSES ............................. 54 2.9 MAIN STRUCTURES AND STRUCTURAL EVOLUTION ......................................... 55 2.10 DISCUSSION: MODELS AND OPEN PROBLEMS ...................................................... 56 2.10.1 Building up the continental crust: the Paleo- to Mesoarchean rock record ........ 56 2.10.2 The record of plate tectonics: the Meso-Neoarchean .......................................... 57 2.10.3 Evolution of the Minas Basin .............................................................................. 59 2.10.4 The Minas accretionary orogeny ......................................................................... 59 2.10.5 Questions for future research .............................................................................. 62 CHAPTER 3 - THE NEOARCHEAN TRANSITION BETWEEN MEDIUM- AND HIGH-K GRANITOIDS: CLUES FROM THE SOUTHERN SÃO FRANCISCO CRATON (BRAZIL) . 65 ABSTRACT ................................................................................................................................ 65 3.1 INTRODUCTION ............................................................................................................ 66 3.2 REGIONAL GEOLOGY .................................................................................................. 67 3.2.1 The Southern São Francisco craton......................................................................