SEDIMENTARY NATURE OF EL AAWAG PLAYA
SOUTHWESTERN SINAI, EGYPT
HASSAN S. HASSAN
Housing and Building Research Center Giza Egypt
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Wadi El Aawag run contiguous to the Qabiliyat mass, receiving many small tributaries coming down-eastward from this mass. The wadi fan forms a playa surface, which is dissected by many wadis draining the basement area. The Pre Quaternary sediments in the study area comprise both Precambrian rocks and Phanerozoic sediments. No Carboniferous sediments were recorded in southwest Sinai; the Naqus Formation is overlain by Lower Cretaceous Malha Formation.
The petrographical, textural and mineralogical investigations of several samples representing four sections in El Aawag playa have revealed that most of the samples are well sorted clayey silt to sorted silt and minor poorly sorted sand.
The clay minerals resulted from the alteration of acidic basement rocks. Under the microscope, the light fractions of the studied samples are composed of quartz and feldspar minerals, whereas absence of the latter is attributed to their disintegration during transportation. Both opaque (iron oxides) and non opaque minerals are present. Epidotes, zircons and amphiboles are abundant, whereas garnet, tourmaline, staurolite, kyanite, biotite and cassiterite are found in minor percentages. All the studied sediments were probably derived from metamorphic source rocks located within the south Sinai igneous and metamorphic complex. However, the northerly and westerly situated sedimentary plateaus contributed also to the playa sediments through a net work of easterly and southerly flowing wadis.
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