Petrochemical and Radioactive Characteristics of El- Yatima Monzogranite, Central Eastern Desert, Egypt

Abstract

The younger granite in El-Yatima area, Central Eastern Desert, cropped out as an isolated mass intruding the older granitic rocks with sharp contacts. It is of pink to reddish color, equigranular of hypidiomorphic texture being porphyritic in places. It is composed of plagioclase, quartz, perthite and biotite as the main constituent minerals. Petrological and geochemical data assigned the studied granite as monzogranite that exhibits calcalkaline with weak peraluminous affinity, magmatic nature which is emplaced in within-plate tectonic environment as A-type granite. Its uranium content is of magmatic origin which is probably leached from its bearing metamectized zircon. El-Yatima monzogranite is characterized by low fractionated REE pattern [Av. (La/Lu)n = 1.86] with slight enrichment of LREE [Av. (La/Sm)n = 1.46] relative to approximate flat HREE [Av. (Gd/Lu)n = 0.93]. The modeled REE data supports the bulk continental crust (B.C.C.) as a parent source of El-Yatima monzogranite melt which had evolved through 70% partial melting of the parent source followed by 30% fractional crystallization.