Compartimentação estrutural e conectividade hidráulica dos sistemas aquíferos Serra Geral e Guarani: caracterização hidrogeoquímica na região central do Estado do Paraná

The study area is located in central State of Parana, in domains of the homonym basin, with approximately 22,600 km2, constituted by basaltic flows of fhe Serra Geral Formation, Lower Cretaceous (Serra Geral Aquifer System – SGAS) which overlap eolian and fluvial sandstones of the Piramboia and Botucatu formations, Triassic/Jurassic (Guarani Aquifer System – GAS). The study involved cluster analysis, factor analysis, interpretation of the structural framework, Piper diagram analysis, and the physicochemical characterization of 45 completed wells located in the Serra Geral Formation in order to characterize groundwater and to identify areas where the aquifers are most probably connected. The groundwater samples analysed are predominantly of the calcium-bicarbonate type, which is characteristic of the Serra Geral Aquifer System. Only a few samples correspond to sodium-bicarbonate or calcium-magnesium waters, that are interpreted to result from connection between the aquifer systems. Regarding the structural compartmentalization and the physicochemical outcomes, sodium-bicarbonate waters are more frequently observed in the northeastern portions of the study area. In the remainder portions, water typically corresponds to the Serra Geral Aquifer System. The lowest hydrochemical dissimilarities are found in the northwestern portion of the study area. The wells that are anomalous in water composition are located on NW-oriented structural lineaments.