"GEOPHYSICAL PROSPECTING STUDIES TO SPECIFY THE RADIOACTIVE POTENTIALITIES AT MAKHRAG EL-EBEL AREA, SOUTH GABAL MONQUL, NORTH EASTERN DESERT, EGYPT"

Abstract

Makhrag El-Ebel area situated in the northern part of the Eastern Desert of Egypt. It lies between latitudes 27°48'54.25"N and 27°49'28.20"N and longitudes 33° 3'31.73"E and 33° 4'8.90"E The geology of the studied area is a part of the northern segment of the Late-Precambrian Arabian-Nubian Shield. It represents a part of the late Proterozoic Arabian-Nubian Shield, which in turn constitute a part of the larger Pan African Belt. The basement rocks of Makhrag El Ebel area consider a part of the Pan African belt. They comprise Dokhan volcanics which distinguished into (basic and acidic volcanic), younger granite, dolerite dykes, quartz and barite veins and wadi sediments. In the present study, ground geophysical studies (Gamma-ray spectrometric and magnetic) were carried out on grid lines to delineate the structural framework and to define the radiometric anomalous zones in the study areas. Beside, Self-Potential (SP) electric survey was selected to follow the radiometric anomalous zones at deeper depths. The main results of this study summarized as follow: 1. GAMMA-RAY SPECTROMETRY SURVEY The Gamma-ray spectrometric survey was carried out along equally-spaced twenty-six parallel traverse lines of 40 m apart, oriented nearly in a N-S direction, using a Czech made Gamma-ray Spectrometer model GS-512, with a high sensitivity of 0.01 Ur. This direction was chosen to cross the general geologic structural features of the study area. The measurements were collected at 20 m regular station separation along the traverse lines. A set of spectrometric filled colored contour maps are produced to represent the distributions of the absolute radioactive elements (TC, eU, eTh and K) and their ratios (eU/eTh, eU/K, and eTh/K).