Document Type : Original Article


1 Geology Department, Faculty of Science, South Valley University, Qena,Egypt

2 Geology department,Faculty of Science,South Valley University, Qena, Egypt.

3 Geology department,Faculty Of Scinece, South Valley University,Qena,Egypt.

4 Nuclear Materials Authority, Cairo,Egypt.


The current work aims to study the phosphorite deposits of the Late Cretaceous age that are belonging to the Duwi Formation. They well exposed in Sibaiya area in the form of oxidized phosphorite with yellowish to brown colour and non-oxidized phosphorite in some parts with grey to black colour. This Formation could be classified into lower phosphorite, middle shale and upper phosphorite members. The lower phosphorite member is the most economic one. The average thickness of this member is 3.3 m in west Sibaiya, while it reaches 4.8 m in east Sibaiya area. The phosphate beds are composed of peloids,Bioclasts of bone and teeth fragments and Coprolites. Geochemically, The CaO, P2O5, SiO2, Fe2O3 and MgO %, heavy metals Cd, Cr, Cu, Ni, Sr and Zn ppm as well as U, Th and Ra ppm were measured and studied. The result shows that the average of P2O5 and U contents in oxidized phosphorite are 24.18 % and 69 ppm respectively. Meanwhile in non-oxidized phosphorite are 27.8 % and 85 ppm. Traditionally, the variation in P2O5 and U contents in Sbaiya phosphorite rocks are probably related to depositional and digenetic aspects. Generally, the Sibaiya phosphorite could provide an economic value for production of phosphoric acid and extracted of U as by- product.