Banca de DEFESA: RENATA EMILY BRITO DE ARAÚJO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RENATA EMILY BRITO DE ARAÚJO
DATA : 26/02/2018
HORA: 08:30
LOCAL: Auditório do DGEF
TÍTULO:

Early rift fault architecture controls on the deformation band pattern in the Rio do Peixe Basin, Brazil

PALAVRAS-CHAVES:

Deformation bands; border faults; fault growth; reactivation; relation bands per meter; Rio do Peixe basin

PÁGINAS: 61
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

The Cretaceous led to the brittle reactivation of continental-scale Precambrian ductile shear zones and the development of rift basins in northeastern Brazil. These basins commonly exhibit subseismic structures, such as deformation bands. The objective of this study is to analyze the influence of early rift architecture and associated master faults on the occurrence and attributes of deformation bands. We used shuttle radar topography, aeromagnetic, and gravity data to unravel the rift structure and identify master fault segments. In addition, we used an unmanned aerial vehicle (UAV) and a field study to map deformation bands close to the main rift faults. Our results indicated that the Rio do Peixe Basin was formed along the reactivation of the Malta fault with four major fault segments and along the Portalegre fault along two major fault segments. Deformation bands occur in poorly sorted, medium to very coarse sandstones within ~70 m wide hanging wall damage zones at the master border faults. The deformation bands occur as single bands or clusters as far as 5 km from the master faults and are widespread in a structural high bounded by relay ramps. The deformation bands follow the strike or are oblique to the master rift faults. The kinematics of faulted deformation bands are consistent with those of extensional rift faults. In addition, a logarithmic decrease in deformation band frequency occurs away from the master slip surface. The deformation band frequencies peak close to the fault core with values as high as 22-48 bands/m. These observations indicate the influence of reactivated rift faults on the deformation band pattern and evolution, and they contribute to the prediction of the location, strike, and kinematics of deformation bands in continental extensional settings

MEMBROS DA BANCA:
Externo à Instituição - CLÁUDIO LIMEIRA MELLO - UFRJ
Presidente - 350640 - FRANCISCO HILARIO REGO BEZERRA
Interno - 349684 - WALTER EUGENIO DE MEDEIROS