Modelagem estratigráfica do intervalo cenomaniano-turoniano, formações Açu e Jandaíra, na borda sudoeste da Bacia Potiguar

• Autor(a) principal: Garcia, Gustavo [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/124439; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/10-06-2015/000831126.pdf
• topic: Geology, Stratigraphic; Geologia estratigráfica; Geologia estrutural; Modelagem geologica; Carbonatos; Bacias sedimentares; Potiguar, Bacia (RN e CE)

Stratigraphic modeling of depositional systems, based on the physical equations for creation of accommodation space and sedimentation rate, can simulate with reasonable approximation the stratigraphic architecture of depositional sequences through time. Applying this methodology, this study aimed at the development of a numerical model of sedimentation filling between the Middle Cenomanian and the Upper Turonian in the southwestern edge of the onshore Potiguar Basin in northeastern Brazil. This stratigraphic level is characterized by a gradual transition from the siliciclastic succession of the Açu Formation to the carbonate system of the Jandaíra Formation. To achieve the proposed objectives, five key stratigraphic surfaces were identified, three of which were sequence limits (LS1, LS2 and LS3) and two maximum flooding surfaces (SIM1 and SIM2), constituting two 3rd order depositional sequences. Sequence 1 (bottom) and Sequence 2 (top) are represented by transgressive and highstand depositional systems tracts. The simulations using the Dionisos® software had an excellent calibration with the lithological and Gamma Rays profiles in 9 wells evenly distributed in the study area. The simulated results of the transgressive systems tracts of Sequence 1, deposited between 95 (LS1) and 93.6 Ma (SIM1), consist of siliciclastics with a fining upward profile. In the highstand depositional systems tracts of Sequence 1 (between 93.6 - SIM1- and 92.8 Ma - LS2), the simulated lithofacies featured a coarsening upward profile during the siliciclastic sedimentation. Carbonate sedimentation favored by a conspicuous reduction in siliciclastic input (around 60%) started at 93 Ma, due to a climatic change or supposedly an interaction between tectonics and climate. The modeled lithofacies of the transgressive systems tracts of Sequence 2, deposited between 92.8 (LS2) and 92 Ma (SIM2), are made up of a mixed sedimentation, with a predominance of carbonates...