Tectonostratigraphic evolution of the central portion of Rio do Peixe Basin, NE from Brazil
Rifts; Seismic Stratigraphy; Tectonic Systems Tracts; Seismic Attributes; Brazilian Equatorial Margin; Cretaceous
The Rio do Peixe Basin is part of a set of aborted rifts with NE-SW trend along the NE region of Brazil. This axis originated in response to the stress caused by the fragmentation of Pangea during the Mesozoic, and effectively installed during the Cretaceous event that has defined the Brazilian equatorial margin. Further characterization of structural framework allowed the recognition of the structures indicative of the structural style of the basin as well as deformational mechanisms responsible for affecting the sedimentary layers. The Brejo das Freiras fault zone (BFfz), which presents NE-SW trend and locally ENE-WSW, strongly influenced by the basement fabric, deforms the layers and originates folds essentially formed by bending mechanisms, such as drag folds, fault-bending folds, and fault-propagation. The rift tectonosequence, which corresponds to the Rio do Peixe Group, has been compartmentalized in nine depositional sequences and arranged five tectonic systems tracts. Those sequences are bounded by flooding surfaces and are responsible for registering shallowing upwards cycles. The tectonic-sedimentary evolution for the Brejo das Freiras sub-basin proposed in this study is supported by seismic reflection data and geophysical profiles. Tectonic systems tracts related to the initial stages of installation of the rift, succeeded by moments of high and low tectonic activity, have been identified. A set of reflections corresponding to the pre-rift section with occurrence restrict to the depocenter was additionally interpreted. The expected result for the present study, which integrates structural and stratigraphic analysis, is a contribution to the understanding of the tectonic influence on spatial and temporal distribution of depositional systems responsible for filling the basin, allowing the prediction of potential petroleum systems, either directly or by the interpretation of analogs