Hydrochemistry of pampasic ponds belonging to the lower stream bed of Salado River drainage basin (Argentina)

V. CONZONNO, P. MIRETZKY Y A. FERNANDEZ CIRELLI

Nova Friburgo, RJ, Brasil

Simposio; 3rd International Symposium Environmental Geochemistry in Tropical Countries; 1999

Chemical analyses of major ions were performed in some of the pampasic ponds in the lower stream bed of Salado River drainage basin. Results indicated that total dissolved solids had a mean value of 1341 mg/l, where sodium was the most abundant of the cations (80.2%) and chloride (44.2%) and bicarbonate (37.4%) were the predominant anions. Saturation index showed oversaturation with respect to calcite and dolomite. Since groundwater is the main source of surface water, high sodium concentration in the ponds may be explained by a cation exchange process in the loessic sediments of the basin where calcium is replaced by sodium.