Gamma-ray spectrometry and Horizontal-Loop Electromagnetic (HLEM) surveys were carried out, to determine the radioactive anomalous zones and to define the extension of the conductive zones for Wadi Budra area, southwestern Sinai, Egypt. This area is covered by Paleozoic rocks which covered by basaltic sheets.
The gamma-ray spectrometric survey were conducted along a number of N-S profiles, with a profile length of 1100 m, line spacing of 40 m and station intervals of 20 m. The gamma-ray spectrometric maps show different radiometric levels, which reflect the radioelement contents of the various exposed rock types. The highest radiometric levels are located along the northwest-southeast trend and of some scattered parts all over the study area. They are mainly associated with the outcrops of Um Bogma Formation The study area shows that the gamma radiation ranging from 1.6 μR/h to 216 μR/h as a total count, 0.1 to 5.5 % K, 0.1 to 203 ppm eU, 0.1 to 50.3 ppm eTh. Thus, uranium a composite image map is constructed to identify and outline the uranium anomalous zones. This map indicates that seven anomalous uranium zones, it appears that the general levels of radioactivity are controlled by the NNW to NW trends with the exposure of Um-Bogma Formation, and the presence of younger granite in the southeastern part. The (HLEM) maps revealed that the shape of the in-phase component at the northeastern part indicates that the conductive body has a thin width with nearly low dip to the west direction, good conductivity thickness product and shallow depth (11m). Menwhile the southern part of the area revealed a conductive body at a depth of 42 m with low conductivity thickness product.