Downloaded from http://sp.lyellcollection.org/ by guest on April 30, 2019 Late Neoproterozoic–Cambrian granitic magmatism in the Arac¸uaı´ orogen (Brazil), the Eastern Brazilian Pegmatite Province and related mineral resources A. C. PEDROSA-SOARES1*, CRISTINA P. DE CAMPOS2, CARLOS NOCE1, LUIZ CARLOS SILVA3, TIAGO NOVO1, JORGE RONCATO1,SI´LVIA MEDEIROS4, CRISTIANE CASTAN˜ EDA1, GLA´ UCIA QUEIROGA1, ELTON DANTAS5, IVO DUSSIN1 & FERNANDO ALKMIM6 1Universidade Federal de Minas Gerais, IGC–CPMTC, Campus Pampulha, 31270-901 Belo Horizonte, MG, Brazil 2Department of Earth and Environmental Sciences – LMU Theresienstrasse 41/III – 80333, Munich, Germany 3Servic¸o Geolo´gico do Brasil–CPRM, Belo Horizonte, MG, Brazil 4Universidade Estadual do Rio de Janeiro, UERJ–Faculdade de Geologia, Rio de Janeiro, RJ, Brazil 5Universidade de Brası´lia, UnB–IG–Laborato´rio de Geocronologia, Asa Norte, Brası´lia, DF, Brazil 6Universidade Federal de Ouro Preto, DEGEO, Campus do Cruzeiro, Ouro Preto, Brazil *Corresponding author (e-mail:
[email protected]) Abstract: The Arac¸uaı´ orogen extends from the eastern edge of the Sa˜o Francisco craton to the Atlantic margin, in southeastern Brazil. Orogenic igneous rocks, formed from c. 630 to c. 480 Ma, cover one third of this huge area, building up the Eastern Brazilian Pegmatite Province and the most important dimension stone province of Brazil. G1 supersuite (630–585 Ma) mainly consists of tonalite to granodiorite, with mafic to dioritic facies and enclaves, representing a con- tinental calc-alkaline magmatic arc. G2 supersuite mostly includes S-type granites formed during the syn-collisional stage (585–560 Ma), from relatively shallow two-mica granites and related gem-rich pegmatites to deep garnet-biotite granites that are the site of yellow dimension stone deposits.