Abstract
The present work deals with a study of natural radioactivity of various samples of granite rocks from the Umm Gidri area located in North Eastern Desert. In this area, about 300 km apart from El-Minia, some geological investigations were carried out. Several samples of the basement rocks (of the Precambrian Age) 5 m subsurface were obtained from different locations. Suitable samples were prepared for natural gamma ray measurements using a 5 x 5 in. Nal(Tl) scintillation spectrometer. Qualitative analysis of natural gamma radiations from the present samples have revealed the presence of the radioisotopes: K-40, Bi-214, Tl-208 and Ac-228 in meaningful concentrations. These results are thought to correlate with the findings of a recent trace element geological assay done at the same area, and it would be of help in monitoring and assessing the national background radiation levels.