الفهرس 
Chapter One: IntroductionOnly 14 pages are availabe for public view
 |  | from | 130 |  |  |
| | | from | 130 | | |
Abstract
Twenty one rock samples represented the study area were selected and subjected to detailed petrographical and mineralogical analyses using polarizing microscope, X-ray diffraction, scanning electron microscope SEM and EDX examination. Ten phosphatic samples have been analyzed chemically and radiometrically through detailed laboratory work, X-ray fluorescence and HPGe. 1- Petrographical analysis indicates that the main phosphatic particles recognized include; inorganic collophane (pelloids and ooids) and organic debris (fragments of teeth and bones) embedded in micritic to micro-sparitic matrix.
2- Mineralogical analysis revealed that the francolite (carbonate fluorapatite) is the main phosphatic mineral in the analyzed samples. The dominant non-phosphatic minerals are calcite and quartz with minor content of evaporites (gypsum, anhydrite and bassanite).
3- Geochemical analysis : P2O5 fluctuates between 11.7 and 26.5% with an average of 19.54%.
4. The SEM/EDX for the Sudr Chalk phosphates of Wadi El-Quseiyib proved the presence of carnotite mineral [K2 (UO2)2 (VO4)2.3H2O]. Carnotite is a secondary uranium mineral occurs on the grain boundaries in cavities. Carnotite precipitated from shallow groundwater or meteoric water enriched in uranyl and vanadate ions.
5. the environmental impact of the radioactive content in the analyzed phosphatic samples, calculations of many hazards indices have been carried out and compared with the permissible values according to UNSCEAR (2000) and ICRP (2010).The phosphatic exposures in the study area are not safe for construction and prolonged human habitation