Interpretation of vertical electrical soundings by means of ISM, PHT and C-N, case of a ditch in Al-Sharquieh phosphate mine in Syria

Abstract

The main objective of this paper is basically to calibrate and compare the different geoelectrical results obtained by the three interpretative techniques of the inverse slope method (ISM), Pichgin and Habibuleav (PHT) and concentration-number (C-N) fractal modeling with the well lithology of an existing known ditch in the Al-Sharquieh phosphate mine in Syria. Those interpretative techniques are applied herein to interpret the vertical electrical soundings (VES) points measured along a parallel profile to the ditch. ISM reveals the presence of four to five geoelectrical layers in the study region. The PHT allows the determination of the tectonic subsurface features of the study region, by analyzing the non homogeneity points and their distributions along a given geoelectrical profile. The fractal C-N modeling provides the different apparent resistivity ranges dominating in the study region. Good agreements are obtained between the direct observed field lithological descriptions of both wall sides of this ditch, and the results obtained by those three interpretative geoelectrical techniques. The high radioactive readings exceeding four hundred count per second (cps) are due to the presence of secondary uranium accompanied with fractures, cracks and joints. The secondary uranium occurrences accompanied by phosphate deposits are found in the study area in the fractured zones, as determined by the geoelectrical PHT technique. The three mentioned geoelectrical methodologies are therefore used as indirect techniques for delineating the radioactive zones related to uranium prospecting. It is a successful application of the joint use of those three techniques, that could be applied in mining to delimit the subsurface geological structure. The reliability and efficacy of (ISM), (PHT), and (C-N) fractal modeling techniques are consequently well confirmed, and it is therefore recommended to use and apply them for characterizing and describing similar lithological phosphatic sequences, and for several shallow mining, environmental and civil engineering applications.