Caracterización hidroquímica e isotópica del acuífero de la meseta basáltica del departamento Puelén, La Pampa

Abstract

The main objective of this work is the isotopic and hydrochemical characterization of theaquifer is situated in the basaltic meseta?s area, in the department Puelén, Province of LaPampa.The area is characterized because the land surface is covered by lava flows, whichform a softly wavy stratum, among them, we can find hollows, which have springs with smallflow and short draining that lose themselves in almost permanent saltpeter beds.The depthof the phreatic level was determined in 62 control points with which, a piezometric map waselaborated. 68 underground water?s patterns of excavated holes, springs, and distributeddrillings in the area, 53 for hydrochemical analysis and 15 for δ 18O y δ 2H determinationswere gathered. The hydrochemical characterization of groundwater indicates that 96% areclassified as sodium chlorides and 4% remaining as sodium sulfated. According to theArgentinean Alimentary Code´s regulations, none of the samples are suitable for humanconsumption, and are not recommended for irrigation according to the Riverside´s criterionbut most are very good for animal consumption.The isotopic composition of groundwater inthe study area is generally consistent with the World Meteoric Water Line. The shallow wellsin the basalt and the springs have average values more depleted (δ18O y δ2H) than theperforations built in sediments.The area of greatest importance hydrologically thisrepresented by the basaltic area, which is developed mainly in the center and west of thestudy area, taking shape dendritic toward the southeast.