f Mapping of natural tracers with electrical resistivity and self-potential prospecting methods in a groundwater experimental test site

A geophysical survey, based on electrical imaging and self-potential techniques, was carried out in a groundwater experimental test site located in Montalto Uffugo (Cosenza, Southern Italy). The aquifer concerned with the test site is controlled by a system of wells and piezometric sensors (Fig.1). From a geological point of view, the investigated area represents a valley of recent formation with alluvial, conglomeratic and sandy deposits. In particular, the direct soundings carried out in the wells area identified the presence of a thick layer of silty sand (from 11 to 40 m below the earth surface) covered by an alluvial layer (from 0 to 7 m) with the interpolation of a thin layer of clay (from 7 to 11 m). From this, we have the presence of a local shallow perched groundwater in the alluvium, sustained by the clay layer, and a deeper confined groundwater in the silty sand layer (Troisi et al., 1993).