Banca de QUALIFICAÇÃO: CARLA HEMILLAY DE OLIVEIRA SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : CARLA HEMILLAY DE OLIVEIRA SANTOS
DATA : 18/07/2016
HORA: 14:30
LOCAL: Laboratório de Geologia e Geofísica do Petróleo – LGGP
TÍTULO:

Expressão Estrutural do Lineamento Transbrasiliano na porção sul-sudoeste da Bacia do Parnaíba

PALAVRAS-CHAVES:

Transbrasiliano Lineament; Parnaíba Basin; Structural expression

PÁGINAS: 20
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

The Transbrasiliano lineament (hereafter referred as LTB) is a major shear zone NE-SW trending, and length of over 2700 km in Brazil. About 900 km of the LTB occur in the substrate of the Parnaíba Basin inferred with aerogravimetric and magnetic data as a plastic shear zone with strike-slip dextral kinematics, similar to that seen in the outcrops of the crystalline basement in the NW of Ceará and east of Tocantins . In basin itself, the reactivation of the LTB is expressed on the surface as NE-orientated lineaments beams corresponding to faults or fractures, intercepting Paleozoic units cretaceous of BPAR. This paper addresses the structural signature and age of reactivations of LTB in the southern region of the basin, from the south of Palmas (TO) to SE Alto Parnaíba (MA-PI). In the crystalline basement, the LTB's dextral kinematics displays stages of high and low temperature, similar to the ones observed at the North-west of Ceará state, where the age of the latter stage is estimated in the Ediacaran-Cambrian interval. In lithostratigraphic units of Parnaíba Basin, reactivation events are distinguished in fragile or hydroplastic regime. The older one displays transcurrent sinistral kinematics, mainly represented as deformation bands and NE-orientated faults  combined with oblique or normal slip structures (and joints or dilational deformation bands) with orientation ranging from N-S to NNW, partly antithetical to the main NE-trending lineaments. At SE of Alto Parnaíba (MA), on the highway to Gilbués (PI), flower structures originated from that event are thickening features of faults' adjacent layers, alternating structures of contraction and strain at their tips or bridges. Observed in the Pedra do Fogo Formation, these syndeposicional deformation features allow to infer a Neopermian age for this reactivation, however reaching the Triassic due to its overprinting in the Sambaíba Formation. The second set of structures are extensional joints or oblique slip and normal faults associated with a N / NNE extension, recorded in the early Jurassic basic rocks of the Mosquito Suite (as well as in overlying sedimentary rocks tentatively correlated to the Corda Formation, in the region of Lizarda (TO). The third set of structures, characterized by normal or normal oblique faults NE-oriented, displays NW extension and, like similar systems in east-central portion of the Parnaíba Basin, are correlated to the rifting event in the Brazilian Eastern Margin during the Early Cretaceous. Finally, a fourth event, more restricted, is tentatively characterized by a NE extension which would be compatible with the transtensional which started the opening of Equatorial Margin during the Aptian-Cenomanian age interval, recorded in the Cretaceous units of the Urucuia Group.

MEMBROS DA BANCA:
Externo ao Programa - 2490483 - ALEX FRANCISCO ANTUNES
Presidente - 346469 - EMANUEL FERRAZ JARDIM DE SA
Interno - 1217847 - FERNANDO CESAR ALVES DA SILVA