Ground gamma-ray spectrometry allows obtaining high resolution data that enables better recognition and mapping of an anomaly observed on maps of airborne survey data. Airborne gamma-ray spectrometric survey recently conducted by the Nuclear Materials Authority (NMA) of Egypt indicated that the region of Southwestern Sinai attains considerable radiometric anomalies. Therefore, detailed ground follow-up gamma-ray spectrometric survey was carried out in Wadi Elseih-Baba area, as a part of Southwestern Sinai. This area is mostly covered by Paleozoic and Quaternary sediments.
The interpretation of the acquired spectral radiometric data relies on two essential interpretation techniques. The first one is the composite image technique which combines any three radioelement parameters and/or their ratios to generate interpretable composite colour image maps. Meanwhile, the second one is the uranium migration technique, which shows the amount of migrated uranium, in and out of the rock units, in an area.
The interpretation of the gamma-ray spectrometric data of the study area proved that their radiation levels, in general, are low compared with the surroundings since they recorded 49 Ur, 36 ppm, 22.5 ppm, and 4.5 % as maximum values for TC, eU, eTh and K% respectively. It was found that the radiometric levels over the geologically mapped rock units express their mineralogical composition and the mapped radiometric anomalies are spatially correlated with Um-Bogma and Magharet Elmaiah formations. The application of uranium migration technique showed that uranium is migrated out from the outcropped rock units in the area, and its migrated amounts (Um) recorded negative values with slight differentiation between the rates of migration in the rock units