الفهرس 
CHAPTER (1)يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
Fifty one samples were collected from ten exposed Quaternary Nile sediments and the Holocene sand sheets sections in the Kafr el Gebel area. These ten sections are Kafr El Gebel Gravels, Kafr El Gebel I which was divided into 6 sections (1,2,3,4,5,6), Kafr El Gebel II, Sand Sheets I and II, they were measured and described in the field. Kafr el Gebel Gravels belongs to Early Pleistocene, Kafr el Gebel I sections belong to Middle Pleistocene, Kafr el Gebel II belongs to Late Pleistocene whereas, Sand Sheets I and II belong to the Holocene. The Middle Pleistocene sections are correlated with Abbassia Formation whereas; the Early Pleistocene section is correlated with Qasr el Basil Formation. The grain size analysis of the Quaternary sediments is characterized by a large planar scale cross bedding coarse and very coarse sand of the channel bar that indicates a high energy current of the defunct braided channels, whereas, sand sheets I and II were derived from the channel bars of the Pleistocene Nile terraces.
The gravels of Kafr El Gebel Gravels section are bladed to disc shape. This indicates that these gravels are transported and deposited by the channel water currents.
The investigated thin sections revealed that most of the samples are derived from sedimentary origin beside few igneous and metamorphic clasts. These investigations indicate that the provenances of these gravels are derived from older formations (Eocene, Oligocene and Miocene) whereas; igneous and metamorphic clasts are most likely from the Red Sea Hills.
X-ray diffraction analyses of samples show that the identified minerals assemblages of the studied samples are quartz, albite, calcite, gypsum and illite. The presence of albite means that the sediments are derived from acidic igneous rocks. Whereas, gypsum is derived from Miocene evaporites.
Geochemical analysis of sections Kafr El Gebel Gravels, Kafr El Gebel I-1, Kafr El Gebel I-2 and Kafr El Gebel I-3 shows that these sediments are mainly composed of SiO2. It is the most abundant oxide, this fact may be related to the abundance of quartz and chert fragments in the studied samples as revealed from the petrographical characteristics. The enrichment of SiO2 over Al2O3 is may be due to the mechanical and chemical process in source rocks. This silica enrichment reflects the duration and intensity of weathering and destruction of other minerals during transportation.
CaO oxide shows a high ratio in the Early Pleistocene more than the Middle Pleistocene. Whereas, the other major oxides such as SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, K2O and P2O5 oxides show high ratios in the Middle Pleistocene more than the Early Pleistocene. These observations confirmed that the Early Pleistocene sediments are derived from the Red Sea Hills as local tributaries but the Middle Pleistocene sediments are derived from the Ethiopian tributaries.
The identified non-opaque heavy minerals are zircon, tourmaline and rutile of the ultrastable group. Epidote, staurolite, kyanite and garnet of the metastable group. Amphibole is mainly represented by hornblende while pyroxene is mainly represented by augite of the unstable group. ZTR index of the studied samples lies below 25 % which indicating mineralogically immature sediments.