GEOCHEMICAL CHARACTERISTCS AND URANIUM-THORIUM DISTRBUTION OF BASALTIC ROCKS FROM DOKHAN VOLCANICS, QIFT-QUESEIR ROAD, EASTERN DESERT OF EGYPT

Document Type : Research and Reference

Author

Nuclear Materials Authority, Cairo, Egypt

Abstract

The present work deals with geochemical characteristics and radioactivity of basaltic rocks from Dokhan Volcanics, gift-queseir road, Eastern desert, Egypt.
Geochemically, the studied Dokhan Volcanics seem to have originated from calc-alkaline magmas which were developed in an island arc tectonic setting. The basaltic volcanics (~2.5km2) posses an elongate outcrop with N-S long axis. Normalized trace element patterns show enrichment in LILEs (Rb, Ba, K, Th) relative to HFSEs (Nb, Zr, P, and Ti) and are very similar to calc-alkaline subduction-related rocks from orogenic belts. A subduction-related tectonic setting for the emplacement of the investigated rocks is indicated by the petrological and geochemical evidences.
The concentrations of U and Th in the studied Dokhan volcanics were controlled by magmatic processes indicated by the positive relation between U and Th and U-Zr in addition to weak negative relation between U and K/Rb.