Fig 1.
a) Location map for the investigated Hamadat area in the Eastern Desert, and (b) Lithostratigraphic column for the studied area.
Fig 2.
a) Field photographs showing the general overview of the Hamadat phosphatic mine, b) Close up photographs showing phosphatic beds from which the samples were collected, b-c) Various types of phosphate samples within the Hamadat Mine where c) shows the grey siliceous phosphorite and d) display the yellow calcareous phosphorite, e) photomicrographs show the rounded to subrounded phosphatic pellets (PP) surrounded by cryptocrystalline siliceous material, and f) bone fragments (BF), shells and phosphatic pellets impeded and surrounded with calcareous materials (CC).
Fig 3.
Binary relation between P2O5 and (a) Al2O3, (b) Fe2O3, (c) Na2O, and (d) U + Th contents of the Hamadat phosphorites, where r is the calculated correlation coefficient.
Table 1.
An example of a representative whole-rock geochemical study of the Hamadat Phosphorites that were analyzed (Central Eastern Desert, Egypt).
Fig 4.
226Ra, 232Th, and 40K Radioelement activity concentrations.
Table 2.
Radioelement activity concentrations (A) (226Ra, 232Th, and 40K).
Table 3.
Phosphate rocks from a variety of countries were tested to determine the activity concentration of 226Ra, 232Th and 40K (Bq kg-1).
Table 4.
Annual effective dose (AED), radium equivalent activity (Raeq), dose rate (D), external hazards index (Hex) and internal hazards index (Hin), and excess lifetime cancer risk (ELCR) were measured for the samples.
Table 5.
Descriptive statistics of 238U, 232Th and 40K (Bq kg-1) in the Hamadat mine area.
Fig 5.
Correlation coefficients illustrate the relation between the radionuclides 226Ra, 232Th, 40K, and radiation hazard parameters at the Hamadat mine area.
Table 6.
Activity concentrations of 226Ra, 238U, 232Th and 40K in phosphate deposits from different countries.