COMPARTIMENTAÇÃO ESTRUTURAL DAS FORMAÇÕES PIRAMBÓIA E BOTUCATU NA REGIÃO DE SÃO JERÔNIMO DA SERRA, ESTADO DO PARANÁ

Abstract

STRUCTURAL FRAMEWORK OF PIRAMBÓIA AND BOTUCATU SANDSTONES IN THE REGION OF SÃO JERÔNIMO DA SERRA-PARANÁ STATE-SOUTH BRAZIL The description and interpretation of the structural framework in the Pirambóia and Botucatu formations (São Bento Group-Mesozoic) of the intracratonic Paraná Basin is presented. The study area is located in Paraná State (South Brazil) which include the city of São Jerônimo da Serra, southeastern portion of the Paraná Intracratonic Basin. The stratigraphic sequence comprises aeolian porous quartz-sandstones and subordinate conglomerates and siltstones which constitute potential hydrocarbon and groundwater reservoirs, involving one of the most important recharge areas of the Guarani Aquifer System. In terms of the regional geological context, the area is located at the northeastern side of the Ponta Grossa Arch, specifically at the São Jerônimo-Curiúva magnetic lineament, which exhibits a notorious density of dolerite dykes and associated faulting system (average strike N45W). Field data, structural and 3D digital relief modeling and analysis and aerial photograph interpretation were used. The first-order structural feature is a conjugate fracture system described as: 1) normal to sinistral N35-80W faults associated with zones of major lineament concentration, dykes and deformation bands; 2) secondary N50E dextral faults locally associated with deformation bands. Secondary E-W and N-S faults were also observed, which together with the first-order structural features promote an important compartmentation of the Guarani Aquifer and allow for the hydrocarbon migration in the Paraná Basin during the Late Cretaceous.