Sedimentação e estratigrafia de afloramentos do Membro Maruim da Formação Riachuelo na sub-bacia de Sergipe

• Ano de defesa: 2013
• Autor(a) principal: Pereira, Filipa Maria Cabrita da Cunha
• Orientador(a): Garcia, Antônio Jorge Vasconcellos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Geociências e Análise de Bacias
• Palavras-chave em Português: Rochas sedimentares; Sedimentologia; Geociências; Rochas carbonáticas; Bacia de Sergipe-Alagoas; Membro Maruim
• Palavras-chave em Inglês: Carbonate rocks; Earth sciences; Sedimentology
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS
• Link de acesso: https://ri.ufs.br/handle/riufs/5392

Currently, most of the giant fields of oil reservoirs consist of carbonate rocks, and these holds more than 50% of world reserves of this energy resource, thus becoming the target of major importance study the oil industry and consequently, to the academy, where are trained professionals to work in the sector. In Sergipe-Alagoas basin, Riachuelo Formation is characterized by mixed sedimentation, consisting of siliciclastics sediments, coming from the continent, and carbonate sediments of marine origin. These last are the constituents of Maruim Member and correspond to the object of study of this dissertation. In this study, we analyzed in detail four carbonate outcrops, located in the regions of Laranjeiras and Maruim where the sedimentological and stratigraphic analysis took place in order to characterize the vertical succession of the deposits within a stratigraphic framework generated in response to relative changes in sea level. Deposits present in outcrops correspond to a clastic carbonate sedimentation occurred in an environment of inner ramp, in a carbonate homoclinal ramp model. The sedimentary environments are dominated by "not skeletal" grains essentially peloids and oncoids with subordinated ooids and reworked bioclasts. The main bioclasts identified correspond to groups of molluscs, echinoderms and solenoporaceans .red algae In total, 28 lithofacies were defined for the studied outcrops, and the same were individualized by outcrop due to substantial differences in the components identified. By 1D stratigraphic analysis were identified 15 transgressive-regressive cycles throughout the studied section. The analysis of lithofacies characterized stacking patterns that show changes barriers systems over time as a result of variations in the relative sea level, where the two basal outcrops would constitute the top of a depositional sequence and the two top outcrops corresponds to another depositional sequence. It was possible to identify that the deposits of the lower sequence were deposited in a highstand system tract and the top sequence shows sediments deposited in a transgressive system tract, correspondig to the intermediate outcrop and, highstand system tract, which corresponds to the top outcrop.