Application of the Electrical Resistivity Tomography to investigate the stratigraphic architecture of a delta plain: the example of the Crati Delta (Calabria, southern Italy)

We apply the Electrical Resistivity Tomography to investigate the shallow (about 100m) stratigraphy of the Crati Delta plain. In this area, the stratigraphic architecture is made of a late Pleistocene coarsegrained coastal plain passing upward to marine clayey deposits, which are covered by transitional and continental sediments related to the holocenic delta evolution. These three main depositional units correspond to as many different "electrical facies" associations. The lower coarsegrained unit is characterized usually by high resistivity values or low ones if it is saturated? the middle clayeysilty unit consist of low resistivity values? the top unit shows middle/high resistivity values and widespread lensshaped bodies representative respectively of sandysilty sediments and gravelly-sandy channel bodies. In the Crati Delta plain, the various deposits do not show significant seasonal variations of the electrical resistivity because the water table fluctuations is low and the saturated conditions persists always.