Estudio De Los Acuíferos De La Zona De Arrecifes (Pcia. De Bs. As., Argentina) Mediante Sondeos Eléctricos Verticales

The aquifers of the northern zone of Buenos Aires<br>Province (Argentina) were generally studied through<br>well data, at a regional scale. However, it is necessary<br>to know their features at each basin, particularly for<br>agricultural purposes. Well data are very limited and<br>geophysical surveys are very scarce.<br>We previously carried out some vertical electrical<br>soundings (VES) at the Pergamino zone and in this<br>work the survey was continued with eight more<br>soundings at the Arrecifes area. Great differences<br>were encountered, mainly in the depth of the top of<br>the salty aquifer, a limiting factor for a drilling project.<br>Models obtained from VES showed an interface<br>fresh-salty water which deepens towards the SE<br>along the Pergamino rivulet, also having a greater<br>depth at the left margin. Results were compared with<br>conductivity of water samples and well data. It was<br>concluded that there is a deterioration of water quality<br>below 50 m depth at Pergamino zone and below 100<br>m near Arrecifes.