Banca de DEFESA: MARCUS VINICIUS COSTA ALMEIDA JUNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : MARCUS VINICIUS COSTA ALMEIDA JUNIOR
DATA : 04/12/2020
HORA: 09:00
LOCAL: https://conferenciaweb.rnp.br/webconf/colegiado-de-pos-graduacao-em-geologia-ufba
TÍTULO:

PETROGRAPHY, LITHOCHEMISTRY AND GEOCHRONOLOGY FROM GNAISSIC-MIGMATITIC COMPLEX OF THE SALVADOR-ESPLANADA-BOQUIM BELT

 

PALAVRAS-CHAVES:

Salvador-Esplanada-Boquim Belt, Petrography, Lithochemistry, Geochronology

PÁGINAS: 83
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
SUBÁREA: Geologia
ESPECIALIDADE: Petrologia
RESUMO:

The Salvador-Esplanada-Boquim Belt (CSEB) is located in the northeastern portion of the São Francisco Craton, in the states of Bahia and Sergipe, presenting two lithological strips of metamorphic rocks, called Gnáissico-Migmatítico Complex (CGM) and Esplanada-Boquim Granulitic Complex. The present work was restricted to CGM field, petrographic, lithochemical and geochronological studies. Macroscopically, this complex is highly migmatized, with a predominance of the process in its western portion. The petrographic study allowed to classify the rocks as granitic to granodioritic and, subordinately, tonalitic. The rocks were lithochemically divided into sodium, potassium and intermediates, due to their alkalinity, being characterized as peraluminous to metaluminous. Analyzes of trace elements, rare earths and Eu / Eu * ratios allowed to interpret the occurrence of metasomatic processes, based on crustal fusion of a calcium-alkaline nature. Eight U-Pb geochronological analyzes (LA-ICP-MS) were carried out on zircons of the CGM rocks, six of which were embedded and two of granitic dykes. The obtained data allowed to conclude that the CGM rocks were formed between 2150 ± 19 - 2188 ± 30 Ma, while the dykes had their crystallization concomitant to the regional metamorphism process, in approximately 2073 Ma. These metamorphic events are interpreted as products of the collision with the Serrinha Block, generating deformation, compression and uplift of these rocks, configuring the zones of regional shear and shear failures, present in this belt. Subsequently eroded, the granulitic roots of the CSEB were exhumed, stabilizing as it currently stands, with the CGM rocks, located to the east and west of the Esplanada-Boquim Granulitic Complex.

MEMBROS DA BANCA:
Presidente - 1295799 - ANGELA BEATRIZ DE MENEZES LEAL
Interno - 2982944 - JAILMA SANTOS DE SOUZA DE OLIVEIRA
Interno - 2689540 - NATALI DA SILVA BARBOSA
Externo à Instituição - CRISTINE LENZ
Externo à Instituição - ERON PIRES MACEDO