Influence of the Romanche Fracture Zone on the tectono-sedimentary evolution of the Brazilin Equatorial Margin
Transtensional Tectonics; Seismic Stratigraphy; Pull-apart Basin; Flower Structure
The Brazilian Equatorial Margin (BEM) has emerged as an area significant scientific and economic interest due to its high petroleum potential, evidenced by major discoveries along conjugate margins of the Equatorial Atlantic. This study investigates the influence of the Romanche Fracture Zone (RFZ) on the tectono-sedimentary evolution of the Barreirinhas Basin, located in the central sector of the BEM. Based on integrated analysis of five seismic sections and exploratory well data, structures typical of transtensional environments were identified, including normal faults, listric faults, and negative flower structures, affecting both the basement and overlying sedimentary sequences. These features demonstrate strong tectonic control by the RFZ over the morphology of the continental shelf, slope, and the internal compartmentalization of the rift and drift sequences. The evolution of the Barreirinhas Basin reflects a complex interaction between oblique rifting, strike-slip regimes, and later tectonic reactivations, classifying it as a pull-apart basin. The current configuration of the margin, marked by distinct structural segmentations, underscores the fundamental role of fracture zones in the genesis and development of basins along the BEM. The results presented contribute to a better understanding of the structural controls on petroleum systems in the equatorial margin and highlight the importance of future studies involving structural modeling and three-dimensional geophysical characterization.