THE ROLE OF AERORADIOMETRY IN MODIFYING GEOLOGY AND IDENTIFYING ANOMALOUS ZONES, SERBAL-NUKHUL AREA, SINAI PENINSULA, EGYPT

A statistical analysis of the aeroradiometric measurements was conduct ed to determine the characteristics of the different interpreted radio metric-lithologic (IRL) units in the Serbal-Nukhul area, Sinai Peninsu la, Egypt. On the basis of both qualitative and quantitative interpret ation of the aeroradiometric data, 11 groups IRL units comprising 45, each of which is characterized by a definite level and pattern of radi ation, could be outlined. The study assisted in the modification of ge ology, the identification of structures and the exploration of the sig nificant zones of anomalous radioactivity. The minimum radioactivity l evel is 2.23 Ur and is associated with limestone, dolomite and gypsum. Meanwhile, the maximum level is 24.52 Ur and is connected with the yo unger late-to-post orogenic granites. Standard deviation contour and t otal-count radiometric anomaly maps were constructed to identify and o utline the significant zones of anomalously high radioactivity which v ary in maximum intensity from 8.3 to 41.5 mu R. The two maps revealed the existence of 24 strong anomalies exceeding the limit of three stan dard deviations above the arithmetic means and are associated with dif ferent types of rocks. Some of these anomalies were field proved, whil e others required additional field investigations. Statistical analysi s of the trends of steep aeroradiometric gradients was carried out to reveal the surface structures, Four significant trends in the N 20 E, N 15 W, N 35 W and N 65 W directions were revealed; the first of which is considered the most important. Statistical analysis of the general courses of the main wadis (dry valleys) showed three trends in the N 35 E, N 65 E and N 35 W directions, one of them could be correlated to one of the radiometric trends (N 35 W).