Evolução complexa de um meio-gráben: seção rifte da Bacia de Campos baseada em análise sismoestratigráfica

The rift section of the Campos Basin is composed of the basal to intermediate portion of the Fea Lagoon Group, and includes the main basin generating rock, and carbonate reservoir rocks. The interpretation and systematic mapping of 2D seismic lines in a key area of ​​the basin where two half-grains occur, integrated with lithological well data, and the construction of a chronostratigraphic chart, allowed to elaborate an evolutionary model for the initial phase of the bowl. Thus, ten seismostratigraphic units, key boundary surfaces and three earthquakes were defined, representing the main lithological groups of the rift section: edge failure deposits, resedimentary fine grain deposits and resedimentary deposits of coarse grains. The stratigraphy of the Campos Basin was subdivided into tectonic system tracts, reflecting its tectonostratigraphic evolution. The tract of rift start system presents well distributed tectonics. The system tract of high tectonic activity is marked by the significant movement of the edge faults; and the treatment of low tectonic activity systems is characterized by a process offault restriction . The analysis of each evolutionary stage led to the proposition of a tectonostratigraphic model. Initially the siniferous sediments were deposited in a sinformal depression without the presence of edge faults. With continuous grinding and increased tectonic activity, the deformation focused on the main faults, resulting in the formation of two well-structured half-gratings with well-defined fault edges. This phase was followed by a phase of incipient movement of the edge faults until cessation of rifting, resulting in a complex and interdependent filling between the different gutters of the basin during its development.