BEHAVIOR OF THE TRACE AND RARE EARTH ELEMENTS IN THE PEGMATITIC ROCKS OF EL MISSIKAT-EL EREDIYA AREA, CENTRAL EASTERN DESERT, EGYPT

ABD EL MONSIF, MOHAMED; ABU ZEID, EHAB K.

doi:10.21608/nssj.2020.265530

BEHAVIOR OF THE TRACE AND RARE EARTH ELEMENTS IN THE PEGMATITIC ROCKS OF EL MISSIKAT-EL EREDIYA AREA, CENTRAL EASTERN DESERT, EGYPT

Document Type : Original Article

Authors

Nuclear Materials Authority,Cairo, Egypt

10.21608/nssj.2020.265530

Abstract

The pegmatitic rocks of El Missikat-El Erediya area are granitic pegmatites composed mainly of
potash feldspar and quartz. They are low radioactive rocks without any radioactive minerals and have rare
crystals of zircon, xenotime, cassiterite and violet fluorite that considered as good hostile for the rare earth
elements. El Missikat pegmatite follow the trend of primitive rock, while El Erediya pegmatite is more
evolved proved by lower Ba/Rb ratio (0.048), higher Rb/Sr ratio (187.08) and lower Eu concentrations
(<0.05) rather than El Missikat pegmatite. The study concluded four reasons for poverty of the
radioelements in the studied pegmatites 1) Consuming of the radioelements in the earlier rocks (granites),
2) Rarity of the post-magmatic processes, 3) The studied pegmatites originated from low-volatile melt and
4) Leachability of uranium by meteoric water as proved by high Th/U ratio and D-factor.