ABUNDANCIA Y DISTRIBUCIÓN DE LAS CONCENTRACIONES DE FLÚOR EN EL ACUÍFERO FREÁTICO DE LA CUENCA LA BALLENERA, SUDESTE BONAERENSE

CALVI, CAROLINA; MARTINEZ, DANIEL E.; DAPEÑA, CRISTINA; GUTHEIM, FLORENCIA

Mar del Plata

Otro; III Reunión Argentina de Geoquímica de la Superficie; 2014

UNMDP- IIMYC (CONICET), Inst Geol de Costas y Cuaternario

This works presents geochemical results of the La Ballenera basin. The main goal is identify patterns of abundance and distribution of fluoride in groundwater. This basin is located in a plain at the southeast in the province of Buenos Aires. The Ballenera stream has a length of 30 km with N-S direction and discharge in the Atlantic Ocean. The phreatic multilayered aquifer is formed by pampean loessic sediments (sandy silt with silt-clayed intercalations) and variable quantities of calcium carbonate. Samples were taken from 34 wells on October 2013 and 18 samples of superficial water on October 2013 and January 2014. All the samples, superficial and groundwater are sodium bicarbonate type with a pH average of 8.2 and 7.7 respectively. Fluoride concentrations of groundwater vary between 1.1 and 2.5 mg/L (median 1.8 mg/L). The central zone of the basin shows the highest contents of fluoride (median 2.1 mg/L). The fluoride distribution of superficial water exhibits the same trend, possibly because of the gain character of the La Ballenera stream.