GEOLOGY AND RADIOACTIVITY OF ABU FURAD- UMM TAGHIR AREA, EASTER DESERT, EGYPT

Abstract

The Abu Furad-Umm Taghir area was chosen, as a representative area of some basement rocks, for the study of the relationship between geology and radioactivity. The study area covers about 262 km2 and is constituted mainly of migmatite, granitic gneiss, metasediment, metavolcanic, amphibolite, metagabbro and granitoid rocks. Of these different lithologic units migmatites represent the oldest unit exposed within the studied area. They occur in the form of two parallel belts which, on the basis of their composition, are defined as neosome with granitic composition and paleosome that are composed mainly of amphibolite and metavolcanic. Granitic gneisses are exposed in the northern part of te map area. These rocks are distiguished by their low relief, intense • jointing and tracturing as well as by their spheroidal exfoliation weathering. These rocks are characterized by their .wide range in composition varying between tonalite, diorite and granodiorite gneisses and they merge into each other with indifinte contacts.