Wadi Ras Abda has length of about 10 km and width reaching to 50 m, and represents the main part
of the drainage pattern of the studied area that bears the same name. The drainage patterns of the studied
area are generally dendritic and angular patterns to indicate that, the area has been structurally controlled.
The dendritic drainage patterns are predominating at the northern parts where fractures, joints, and faults
are affected. The angular pattern type occurs often at the southern parts owing sharp intersections of main
stream and its tributaries.
Wadi Ras Abda area is dominated by basement rocks encompassing older granitoids, younger gabbros
and younger granites as well as several types of post granitic dikes. The studied area is affected by two
right-lateral strike-slip faults of NE and NW trends and is influenced by a large graben with 3.2 km wide
and extends for 10.4 km in the NW-SE direction. The graben was formed through the interaction of the NWoriented
right-lateral-slip faults of conjugated dip directions due NE and SW. Mineralogical investigation
of three shear zone samples and seven stream sediments samples revealed the presence of several important
heavy minerals. These minerals include magnetite, hematite, ilminite, garnet, zircon, sphene (titanite),
columbite, samarskite, chromite and platinum.