الفهرس 
ARABIC SUMMARY
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Abstract
The precambrian rocks exposed at Wadi Arayis area are differentiated into two major tectonic units, viz. an old infrastructure and a young suprastructural units. The infrastructural unit is exposed at the southwestern part of the map area around Wadi Beitan and extends southwards beyond the limits of the study area. It is separated from the overlying suprastructural unit by a mylonite zone, displaying a NW direction of tectonic transport (D1). Laterly, both the infrastructural and the suprastructural units are folded into a series of plunging anticlines and synclines with their axes extending up to severral kilometers long (D2). The overlying suprastructural unit is sifferentiated into three tectonic units displaying low-grade regional metamorphism up to the greenschist facies. They are arranged according to the field relations as follows starting from the top:
1- Abu Dahr serpentinite range.
2- Arayis ophiolitic melange.
3- Egat metavolcaniclastics.
4- Infrastructural rocks.
The upper two units build up the main dismembered ophiolite association which extends from Wadi Na’am to the west untill Gabal Abu Dahr to the east. After the later (D2) phase of folding, these tectonic inits were intru8ded by autochthonous gabbroic intrusions such as um Eleiga, Arayis and Urga El Rayani gabbroic bodies. These were followed later by Abu Syiel granodiorite bodies which, in turn, were succeeded by the alkaline granite intrusions of Hindust, Egat and Arayis. The latest magmatic activity in the studied area is represented by basic, intermediate, acid and alkaline dykes which are moslty extending E-W. However, NW and NE trends are occassuinally present.