Macururé domain uplift and its influence on Upper Cretaceous turbidity sedimentation of Sergipe Sub-basin, Sergipe-Alagoas Basin

Abstract

The Sergipe-Alagoas Basin is located in northeast Brazil, in a regional context that includes geological terrains of different tectonic settings and ages. The precambrian terrains of the Atlantic Shield are: São Francisco Craton, Pernambuco-Alagoas Massif and Sergipana Fold Belt. The phanerozoic terrains are distributed in Upper Jurassic to Early Cretaceuous aulacogens of the Recôncavo, Tucano and Jatobá basins, including Sergipe-Alagoas Basin, which is the object of this study. The Calumbi Formation, related to the drift stage of the Sergipe-Alagoas Basin sedimentation, is an important hidrocarbon exploration and production target, with senonian reservoirs present in the oil fields of Ilha Pequena, Cidade de Aracaju, Angelim, Brejo Grande, Ponta dos Mangues, Salgo, Robalo, Mero and Piranema. The Calumbi Formation is also a producer in the Terciary reservoirs of Guaricema and Dourado oil fields. The detailed study of genesis and processes related to erosion, transportation and deposition of the Upper Cretaceous sandstones in the Sergipe Sub-basin has brought a better understanding of the sedimentological and structural evolution of the Sergipe-Alagoas Basin, during the Senonian. Provenance studies of the Calumbi Formation, including geochemistry, apatite fission track, sedimentology and seismic data, indicates Macururé Domain (Nothern Sergipana Fold Belt) as the main source of the Campanian to Maastrichtian sandstones, with some contribution from the São Francisco Craton. The diferential uplift of these terrains could have resulted from oceanic fracture zones activation movements (Sergipe and Maceió-Ascensão fracture zones), induced by oceanic seafloor spreading and controlled by ancient shear zones in the basement (faults related to Vaza-Barris and São Miguel do Aleixo systems).