Hydro-geoelectric Properties of Asmari and Ilam-Sarvak Formations in Susan Syncline, North Izeh

Hydro-geoelectric properties of the Asmari and Ilam-Sarvak formations in Susan Syncline (located in Middle Karoon Basin), North of Izeh, were investigated to recognize electrical resistivity ranges of dry and wet limestone, karstification, and fractures and determine the areas with high potential for groundwater exploitation. For this purpose, the resistivity data were collected in 245 vertical geoelectric sounding (VES) using Schlumberger array in the contact of limestone and adjacent alluvium. The resistivity data were interpreted as one-dimensional and two-dimensional tomography (using RES2DINV software). The resistivity curves of VES in the Asmari Formation have lower value and ranges of resistivity than the Ilam-Sarvak Formation which can be understood by high yield of the aquifers from the smooth descending VES curves. Interpretation of two-dimensional geoelectrical tomography revealed that the Ilam - Sarvak Formations have considerable potential groundwater in crushed zones but the karst development and cavities in them are less than the Asmari limestone. The spring discharges from the Ilam-Sravak Formations in Susan area is in relation with the contact of compact limestone and water bearing fractured zones. Despite the lack of major springs in the Susan Syncline,the results of the hydro-geoelectrical investigation showed the Asmari limestone aquifer, has a high groundwater potential. The electrical resistivity of the Asmari Formation is lower than the Ilam-Sravak ones because of the higher porosity of limestone matrix in the former.