Mineralogical, geochemical characteristics and origin of Late Cretaceous phosphorite in Duwi Formation (Geble Duwi Mine), Red Sea region, Egypt

Generally, the enrichment of the trace elements, REEs and uranium may have occurred during diagenesis. The studied phosphate samples were compared to the average of the Average World Phosphorite (AWP) and the Average Shale Composition (ASC). The major, trace and rare earth elements contents are compared with those in Egypt, North African, Asian and other localities. The ratios V/Cr, V/(V + Ni) and Mo/Al and the high concentrations of the redox sensitive elements revealed that the studied phosphates were deposited under anoxic reducing marine environments coupled with hydrothermal solutions, which is comparable to the environmental condition of the associated black shales. The concentration of the trace and toxic elements in the studied samples are considered to be below the limits for most field-grown crops.