CONTRIBUTIONS TO THE GEOLOGY AND MINERALOGY OF WADI RAS ABDA AREA,NORTH EASTERN DESERT, EGYPT

Abstract

Wadi Ras Abda has length of about 10 km and width reaching to 50 m, and represents the main partof the drainage pattern of the studied area that bears the same name. The drainage patterns of the studiedarea 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 faultsare affected. The angular pattern type occurs often at the southern parts owing sharp intersections of mainstream and its tributaries.Wadi Ras Abda area is dominated by basement rocks encompassing older granitoids, younger gabbrosand younger granites as well as several types of post granitic dikes. The studied area is affected by tworight-lateral strike-slip faults of NE and NW trends and is influenced by a large graben with 3.2 km wideand extends for 10.4 km in the NW-SE direction. The graben was formed through the interaction of the NWorientedright-lateral-slip faults of conjugated dip directions due NE and SW. Mineralogical investigationof three shear zone samples and seven stream sediments samples revealed the presence of several importantheavy minerals. These minerals include magnetite, hematite, ilminite, garnet, zircon, sphene (titanite),columbite, samarskite, chromite and platinum.