CONTRIBUTION TO THE GEOLOGY, PETROLOGY AND AIRBORNE GAMMA-RAY SPECTROMETRY OF GABAL EL-MUEILHA GRANITIC ROCKS, SOUTHERN EASTERN DESERT, EGYPT

Gabal (G.) El-Mueilha Granitic rocks are represented by an oval shaped stock that intruding the
surrounding older rock units including ophiolitic mélange, metavolcanics, older granitoids and younger
gabbros and sending several offshoots into them. The study area is affected by several fault systems in
NW-SE, NE-SW and N-S directions. Petrographically, these younger granites are mainly represented by
muscovite granite (syenogranite) that shows different degrees of albitization especially at the peripheral
parts of the stock beside the ferrugination and silicification. The main accessory minerals are cassiterite,
fluorite, zircon, beryl, monazite, thorite and uranothorite which are responsible for the radioactive
anomalies in G. El-Mueilha syenogranitic mass. The airborne gamma ray spectrometry shows high
radioactive anomaly restricted to the younger granitic mass relative to the other surrounding rocks that have
low to moderate radioactivity. The eTh/eU ratio of G. El-Mueilha syenogranite indicates U-enrichment
especially during albitization processes.