Banca de QUALIFICAÇÃO: ANA MILENA NEMOCON ROMERO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ANA MILENA NEMOCON ROMERO
DATA : 20/04/2017
HORA: 09:00
LOCAL: Auditório do DGEF
TÍTULO:

New constraints to crustal properties of uplift and rift zones in the western Profile of the Borborema Province, NE Brazil, from receiver function analysis

PALAVRAS-CHAVES:

Crustal thinning, uplift, rift, receiver function

PÁGINAS: 12
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

Crustal thinning beneath uplift and rift zones deserves special attention. Rift structures and the transform margin in the Borborema Province (BP) were formed during the Cretaceous as a result of the opening of the Atlantic ocean. After this event, the evolution of the Province was marked by episodes of uplift, which might have been simultaneous with episodes of volcanism in the Cenozoic. A prominent expression of uplift in the western profile 
is the Chapada do Araripe of ~ 1000 m limited to nothern by Cariri-Potiguar rift zone as well 
as Patos shear zone and to southern by Pernambuco shear zone. Two main inversion models to Araripe basin have been proposed, horizontal compressive stress and epeirogenic inversion. However, the lack of crustal thinning data had not allowed a better analysis and support. This paper provides new constraints on models regarding the structure and dynamics in the long of a profile approximately NS direction at western of the PB, few studied previously. This profile is crossed by relevant structures as: part of Cariri-Potiguar rift zone (~200 km), the uplift of the Araripe Basin (~67 km), the Pernambuco shear zone (~135 km) and São Francisco craton (~260 km). Through a completed receiver-function analysis, which is a straightforward method of extracting constraints on crust and upper-mantle structure from teleseismic waveforms, recorded of temporary network of 13 collocated seismic stations. Our measurements reveal that significant thinning ~10 km relative to the un-rifted parts of the BP, agrees with others continental rifts; also suggest that the greater amount of crustal thinning, 34,5 km, is beneath Cariri-Potiguar 
rift zone and not beneath Araripe basin contradicting to previous studies, uplift models and discussions; other interesting result suggest two intra-crustal discontinuities in the upper crust of 3,6 and 4,0 km/s to around 5-10 and 15-20 km respectively; velocities finding of 4.3 km/s close to crust-mantle boundary and upper mantle velocities are around 4.5 km/s.

MEMBROS DA BANCA:
Interno - 1451214 - ADERSON FARIAS DO NASCIMENTO
Presidente - 1863578 - JORDI JULIA CASAS
Interno - 349684 - WALTER EUGENIO DE MEDEIROS
Externo à Instituição - XAVIER GARCIA MARTINEZ - UNIBARCELONA