Banca de DEFESA: LUCAS TEIXEIRA DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LUCAS TEIXEIRA DE SOUZA
DATA : 13/12/2019
HORA: 14:00
LOCAL: Instituto de Geociências
TÍTULO:

TECTONIC AND GEOCHRONOLOGY (U-PB) OF THE SUTURE ZONE BETWEEN ITABUNA-SALVADOR-CURAÇÁ AND JEQUIE BLOCKS, BAHIA, BRAZIL

PALAVRAS-CHAVES:

Suture Zone, São Francisco Craton, Petrography, Geochemistry, Airborne Geophysical Maps

PÁGINAS: 87
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
SUBÁREA: Geologia
ESPECIALIDADE: Geotectônica
RESUMO:

The study area of this research is located in the central portion of the largest tectonic feature of the state of Bahia, the São Francisco Craton (SFC). More specifically on the boundaries between two of the main blocks that make up the craton, the Jequié, and Itabuna-Salvador-Curaçá blocks. The research mainly aimed at the reevaluation of the boundary between these blocks, using airborne geophysical maps and geological, structural, petrographic, geochemical and U-Pb geochronology data of rocks that occur in this region, to contribute to the knowledge of the geotectonic evolution that shaped the rocks in this location. The airborne geophysical maps used were the radiometric and magnetometric methods, which allowed the individualization of five radiometric domains and six magnetometric zones. Structural analysis identified four phases of deformation characteristic of a transpressional zone. The petrographic description showed that the lithology mineralogy is very similar, having as discriminating characteristics the degrees of deformation and the presence of some index minerals of the granulite facies. The lithogeochemical studies showed a context of high-K peraluminous to high-alumina calcine rocks, where the incompatible elements were responsible for the individualization of the BJ lithotypes due to lower ETR fractionation. The UPb geochronology determined crystallization ages for the basement rocks around 2.7-2.6 Ga (zircon U-Pb) and metamorphic peak at 2.07-2.06 Ga (U-Pb in zircon), with an age difference between the edge and center of the zircons with a range of 40-30 Ma, interpreted as the period between the metamorphic peak and orogenetic collapse. The present study proposes a modification of the boundary between blocks, based on the data set obtained by these methods.

MEMBROS DA BANCA:
Interno - 1295799 - ANGELA BEATRIZ DE MENEZES LEAL
Externo à Instituição - ERON PIRES MACEDO - SGB
Presidente - 268656 - LUIZ CESAR CORREA GOMES
Interno - 2689540 - NATALI DA SILVA BARBOSA
Externo à Instituição - RITA CUNHA LEAL MENEZES DE OLIVEIRA