Influência da Zona de Fratura Romanche no arcabouço tectonoestratigráfico da Bacia de Barreirnhas, NE, Brasil

Abstract

The Barreirinhas Basin is located in the central portion of the Brazilian Equatorial Margin (BEM). Its origin is linked to the rifting and fragmentation process of Pangea in the Eo-Cretaceous. It happened when the continental lithosphere in the north of the Barreinhas Basin was uplifted and fractured by transforming movements Romanche Fracture Zone (RFZ). This Basin was controlled by a mixed tectonic regime: distensional stresses, resulted from the separation of Pangea, associated with shearing stresses. The main objective is to investigate how the RFZ has influenciated the evolutionary history and the main structures of the Barreirinhas Basin. In addition, the study was important to favoring the contribution of knowledge about the region through the construction of geophysical and geological models, which structurally and stratigraphically portray the internal architecture offshore and onshore portions of the Basin. For this purpose, eight 2D seismic sections were interpreted together with information from five well geophysical profiles. In order to assist in the interpretation process, seismic attributes were used to highlight both seismic stratigraphic horizons and structural features. The results show the predominance of lytic faults of normal tailings in the rift sequence and the presence of transtensional kinematics, represented by negative flower structures, due to the dextral movement during the separation of South America and Africa. In the more distal portions of the emerged Basin, it is observed that reactivations of the RFZ influenced from Aptian previous faults to the Holocene, and therefore have a strong impact on the evolutionary history of the BEM, in particular, the Barreirinhas Basin.