Wadi Abu Rusheid - Wadi Sikait area lies in the southern part of the Eastern Desert of Egypt. It is located about 40 km west of the Red Sea coast, along Wadi Nugrus which is a tributary of Wadi El Gemal. The surrounding area of lamprophyre dykes comprises, ophiolitic melange, cataclastic (mylonitic) rocks, granitic rocks and post granitic dykes and veins. The lamprophyre dyke is intruding in the shear zone along the mylonitic rocks. This shear zone varies in thickness from 0.5 m to 2.0 m and up to 1.0 km long. The alteration is represented by the sericitization and argilization, as well as hematitization.

Petrographically, it is composed mainly of plagioclases phenocrysts embedded in fine-grained groundmass of plagioclase, ferromagnesian minerals and quartz. U-minerals, apatite and opaques are accessory. The mylonitic rock consists essentially of quartz, K-feldspars, plagioclases, biotite and muscovite. Zircon, xenotime, monazite, allanite, fluorite and opaques are accessories.

The mineralizations of the mylonitic rocks and lamprophyre dykes at the studied area can be classified on basis of mode of occurrence and lithological associations into: -1) Uranium minerals (kasolite), 2) Base metals minerals (sphalerite - cerussite) and 3) REE and Niobium - Tantalum bearing minerals (xenotime - monazite - tantalite - fergusonite - allanite - apatite - zircon).

Geochemically, the studied lamprophyre dykes are characterized by anomalously high REEs contents ranging from 1035 to 3980 ppm. The LRREs are about 200 to 1000 times the normalized chondritic values while the HREEs recorded values about 700 to 5000 times compared to the reference chondrite (HREEs>LREEs). The geochemical investigations indicate the REE patterns of the lamprophyres dykes in Wadi Abu Rusheid - Wadi Sikait area show HREE enrichment and strong Eu negative anomalies. The presence of REE-rich hydrothermal phases suggests a significant mobilization and deposition of REEs, especially La, Pr, and Sm (LREE) and Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu (HREE).

Radiometrically, there are relatively positive relation between eU vs. eTh, slightly strong positive relation between eU vs. K%, eU vs. eU/eTh and weakly positive relation between eTh vs. K%. These positive values of eU indicating the migration of uranium and redeposit in lamprophyre dykes, leading to the enrichment of uranium in lamprophyre dykes from surrounding rocks and enrichment in uranium which related to postmagmatic processes.