U-Pb Geochronology Zircon (La-Icp-Ms) Data of the Gneissic-Migmatitic Complex of Salvador-Esplanada-Boquim Belt, São Francisco Craton, Brazil/Geocronologia U-Pb (La-Icp-Ms) Em Zircões Do Complexo Gnáissico-Migmatítico Do Cinturão Salvador-Esplanada-Boquim, Cráton Do São Francisco, Brasil

Abstract

The Salvador-Esplanada-Boquim Belt (SEBB) is considered a branch of the São Francisco Craton, located in its northeastern portion, in the Brazilian states of Bahia and Sergipe. This paper analyzed the U-Pb (LA-ICP-MS) geochronology on the Gneissic-Migmatitic Complex (GMC) zircons in the rocks of the SEBB. Six analyses were made on the rocks of GMC and two on granitic dykes. The obtained data allowed concluding that the GMC rocks were formed between 2150 ± 19 -2188 ± 30 Ma, while the dykes had their crystallization in line with the process of regional metamorphism in 2073 Ma. These metamorphic evens are interpreted as products of the collision with the Serrinha Block, provoking deformation, compression and uplifting of these rocks. After eroded, the granulitic roots of SEBB were exhumed, stabilizing on the way it is today with the GMC rocks, located on east and west of the Esplanada-Boquim Granulitic Complex.