SEQUENCE STRTIGRAPHY OF THE OLIGOCENE SILICICLASTIC IN NORTHERN EGYPT: IMPLICATIONS FOR GENETIC STRATIGRAPHY AND SEDIMENTARY BASIN MODELING

The non marine Oligocene sediments are exposed in northern Egypt by two formations, Gebel Qatrani and Gebel Ahmer formations, in Fayum, Cairo-Wahat District, 6th of October City, El-Obor City, Nasr City and Cairo-Suez District. The lithologic description Studying the field relationships, lithologic description, grain size analysis and applying the role of sequence stratigraphy led to divided the Gebel Qatrani Formation into five members: Lower Sandstone Member, Claystone Member, Middle Sandstone Member, CSix sedimentary tracts were defined in the Oligocene rock units, either marine or non-marine: estuarine-bay sediment tract includes two tracts rejuvenation of the Estuary ”Ur Nil” sediment tract and Multiple story channel fill or Erosion and infill surfacThe analysis of heavy minerals and studying the microfacies lead to that the Gebel Ahmer Formation is partially equivalent to the Upper Sandstone Member of Gebel Qatrani Formation.Studying of claystone samples by using X-ray diffraction analysis and geochemistery exhibit a great similarities in all samples of Gebel Qatrani members, and reveals the humid climate prevailed during the deposition of all members in Gebel Qatrani FormatiFrom imagination the modeling and studying the paleogeography, it can said that the sediments of estuarine bay of the Oligocene sandstones was supplied from the Ur Nil or Libyan River, which was came from rifted lakes in northern Sudan.