Banca de QUALIFICAÇÃO: GILSIJANE VIEIRA RAMOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : GILSIJANE VIEIRA RAMOS
DATA : 16/10/2017
HORA: 15:00
LOCAL: Laboratório Sismológico - Sala de aula I
TÍTULO:

Application of aeromagnetic surveys in the characterization of seismogenic faults in the Northeast of Brazil

PALAVRAS-CHAVES:

Active faults, Neotectonic, Aeromagnetic Data, Samambaia Fault, Riacho Fundo Fault, Meruoca Granite.

PÁGINAS: 50
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

Brittle reactivations of seismogenic faults in the crystalline basement have been registered in several intraplate regions of the world. The origin of intraplate seismogenic faults and their relationship with basement structures, where they occur, have presented contrasting styles in intraplate region of South America. Recently, aeromagnetic data are being used to identify structural patterns, and their relationship with crystalline basement structures and seismogenic faults. Here we use aeromagnetic data to characterize epicentral areas such as João Câmara and Meruoca Granite, and to understand the role of basement fabric in the seismogenic faults reactivation. The applied methodology involves the application of filters to collaborate in the process of geological and structural interpretation. The filters are used: reduced to the pole, matched filter; Euler deconvolution and Analytical Signal solutions from the PDEPTH tool. The main results for the Samambaia Fault epicentral area, show main trend - NE-SW of interpreted lineaments, we identified that the seismicity reactive the basement structures, we also observed a concordance between the hypocenters and the Euler solutions obtained. For the Riacho Fundo Fault epicentral area, we observe a main trend - EW, disagreeing with the pattern established in previous works of the Borborema Province, we note that the magnetic lineaments agree with the basement structures, thus reactivating the anisotropy of the crystalline basement. The depth established by previous works of the Meruoca Granite is at 3 km, and in this work we can observe a swarm of hypocenters around 5 km deep, confirming the occurrence of hypocenters in the portion of the crystalline basement. The hypocenters in the Meruoca Granite region, mostly caused by the Riacho Fundo fault, reach up to 8.4 km deep. We conclude that in both regions, seismogenic faults reactivates the anisotropy of the basement, and that a continuation of the magnetic sources occurs until a certain depth reaches curie temperature and the materials begin to lose their magnetic properties.

MEMBROS DA BANCA:
Interno - 1451214 - ADERSON FARIAS DO NASCIMENTO
Interno - 1315614 - DAVID LOPES DE CASTRO
Presidente - 350640 - FRANCISCO HILARIO REGO BEZERRA
Interno - 583.103.478-04 - JOAQUIM MENDES FERREIRA - UFRN