Geoelectrical Mapping of the Omalos Plateau/Polje, Chania, Western Crete, Greece

This study case presents the results of a geoelectrical survey that was carried out at Omalos plateau in Chania, Western Crete, Greece. The survey included measurements of resistivity mapping and sounding as well as electrical tomography. The aim of this survey is to image the complex structure of the active karstic system of the Omalos polje. The processing of the measurements indicates three geoelectrical layers. The shallow layer exhibits extremely high electrical resistivity and is attributed to alluvial – dilluvial deposits. The intermediate layer exhibits very low electrical resistivity and reflects mainly the presence of marls (Neogene?). Finally, the lower geoelectrical layer outlines the metamorphic mainly carbonatic bedrock (Tripali unit and Plattenkalk group), whose relief appears highly irregular. At Omalos polje the thickness of post-Mesozoic deposits (terra rossa, clays, sands and gravels) ranges from 40-130 m.