Remarks on the hydrogeological setting of S. Eufemia Lamezia plain through the development of the top surface of the intermediate confined aquifer (central Calabria)

The S. Eufemia Lamezia plain, located in central Calabria, is characterized by the presence of a multi-layered aquifer. In particular, it was studied the intermediate artesian aquifer, content in the Pliocene sands and sandstones. The collection of new lithostratigraphic data, related to drilling for water supplies, allowed to draw the map of the top of intermediate artesian aquifer underlying in the study area. The top surface of sands and sandstones map, presented here, seems to confirm the structural-geological data of the surface showing, also in depth, the conditioning of tectonics on the study area and on the groundwater flow. The analysis of the selected stratigraphic data shows that the studied aquifer is constituted by Pliocene deposits of sand and sandstones, confined to the top by Pliocene clay. Therefore locally hydraulic connections with the shallow aquifer for leackage phenomena are possible. The supply of the studied aquifer happens mainly for lateral recharge because the clay horizon that borders with the top of the aquifer prevents direct transfer of rainfall recharge. However, a reduced recharge rate is due to the meteoric recharge, which is possible in limited parts of the territory to the east of the study area and over. Therefore, this study aims to implement the knowledge of the groundwater flow of S. Eufemia plain by returning the top intermediate confined aquifer map which, is little studied but strongly exploited because, respect to the shallow aquifer, is more productive and more protected by potential contamination due to the presence of the aquiclude/aquitard which isolates it by the top.