Integrated geophysical investigation for mapping of manganese-iron deposits at Wadi Al Sahu area, Sinai, Egypt—a case study

Abstract

This study used data from an investigation into the mapping of manganese-iron (Mn-Fe) mineralization, located within the Um Bogma formation. The ore takes the form of patchy isolated bodies or lenses in the three members of the Um Bogma formation located in East Sinai, Egypt. Magnetic, resistivity, and induced polarization (IP) surveys were applied at the Wadi Al Sahu area to delineate the mineralized ore bodies in terms of depth and extension. The quantitative interpretation of magnetic data was carried out using the 2D analytical signal. The results of the magnetic interpretation indicated that the depths of such ore deposits range from − 2 to − 20 m, and the shape of the magnetized units (assumed to be manganese-iron ore) is lenticular and of small size ranging from 20 to 100 m in width. Three dipole-dipole geo-electrical traverses were carried out along the anomalous sites, the traverse locations selected from the constructed magnetic maps of the study area, and the resistivity and IP measurements along with them. The results of the resistivity and IP inversion indicate that there are conductive and chargeable bodies at a depth that indicate the shape of small Mn-Fe lenses being present and conform to the shape of the Mn-Fe ore mineralization. Integration between the magnetic and geo-electrical data is made to lessen the non-uniqueness problem in geophysical prospecting. In this case, we used electrical resistivity and induced polarization models to delineate the boundaries between different geo-electric units, and these boundaries were used as interfaces between layers with different magnetic susceptibility for magnetic modeling to perform magnetic data inversions.