Petrology, REE Geochemistry and Tetrad Effect of Some Muscovite Granites at Wadi El Gemal Area, South Eastern Desert, Egypt

The muscovite granites at the study area are being emplaced into biotite and ophiolitic mélange settings. They occur in four exposures namely; Umm Seleimat, Sikait, El Kheran Addebaa exposure. presence of garnet flakes may reflect peraluminous nature studied granites. Petrographically, mostly subsolvus consist plagioclase, K-feldspars, quartz, biotite. Garnet, zircon, allanite opaques accessories. textural features these expressed by bent plagioclase lamellae, distorted microcline twinning, deformed mica development myrmekite recrystallization feldspars fine-grained aggregates. Seleimat Sikait more differentiated due to high content K-feldspar LREEs. REE budget decreased from Seleimat-Sikait Kheran-Umm as (514.5 - 495.6) (195.9 197.7), respectively. have lower HREE/LREE (0.12 0.67), relative (0.99 2.06). revealed that chondrite normalized patterns normal M-type tetrad effect, where TE1,3 effect is higher than 1 all samples which implies there was an interaction between melt water-haloid-rich fluid when crystallized magma. Spectrometric values indicate U Th content. Applying mobilization equation proved been originated a late magmatic phase magma very rich radioelements, also majority measurements lie above zero line indicating affected with hydrothermal solutions uranium thorium indicates addition.