Padrão de salinização de águas subterrâneas na bacia do rio Curaçá: Avaliação química e isotópica

Groundwater from crystalline aquifers in the Curaçá basin, northern part of Bahia state, display generally very high salinity. To investigate the origin of this salinization the chemical and stable isotope (±D and ±18O) composition of samples from 16 well boreholes and 2 surface reservoirs was measured. The deuterium and oxygen-18 concentration are much higher in surface samples than in groundwaters, while the major ions concentrations are much higher in groundwater than in surface samples. This indicates that the infiltrating waters that reach the aquifers does not suffer high evaporation and the origin of salinity is from dissolution of salts in the water interaction with the soils and the rocks of the reservoir.