Estudio isotópico e hidroquímico de los acuíferos de la Cuenca Norte Mendocina (ríos Mendoza y Tunuyán)

PANARELLO, HECTOR; DAPEÑA, CRISTINA; GARCIA , ERNESTO; ALVAREZ, A.

Mendoza, Argentina

Congreso; XII Congreso Geológico Argentino y II Congreso de Exploración de Hidrocarburos; 1993

Comisión Congreso Geológico Argentino

This paper reports isotope and chemical results of a study carried out in the northern basin of Mendoza. Duteriu, oxygen-18, carbon-14 and carbon-13 as well as major ions analyses performed on 121 samples of surface and three levels of groundwater lead to the following conclusions: there exist at least three different types of water in the basin, the related to the Mendoza River, very depleted in both, oxygen and deuterium, recharged at high altitude in the Cordillera de los Andes (delta 18-O -18,6 and delta 2-H -140 per mil); the less negative, Tunuyán River type water (delta 18-O -16,7 and delta 2-H -127 per mil) and those of the Pampa de Canota, more enriched (delta 18-O -6,8 and delta 2-H -48 per mil), reflect the recharge coming from western lower hills. By means of the cited differences in the isotopic compositions, it was possible to differentiate the influence on the recharge for the three above mentioned water types. Most the salinization mechanisms are also explained here. Carbon-14 and carbon-13 data alloed, by using the modified Pearson model, to asses the groundwater age and to calculate the groundwater flow velocity towards the NE the Tunuyán River and towards NW the Mendoza River in 4 and 3 m/y, respectively.