Gamma-ray spectrometric investigation of north El-Tor area, southwestern Sinai, Egypt

摘要

Interpretation was executed on the airborne and ground spectrometric data of Abu-Zeneima/Al-Tor area for verifying the significant anomalies as it contains important targets for prospective nuclear materials. Airborne spectrometric survey revealed that younger granites, are characterized by increase in the three main radioactive elements up to 5.4% K, 10?ppm eU and 33?ppm eTh. The western part of the study area includes sedimentary section which contains uranium-bearing phosphate beds. They are characterized by increase of airborne uranium concentration up to 14.2?ppm without potassium or thorium enrichment. The airborne image maps for eU/eTh and eU/K as well as ternary composite map revealed also that there is a promising U-anomaly, associated with the sedimentary section.Detailed ground spectrometric survey for the Cretaceous Nubian sandstone in Wadi Araba indicated that it is characterized by eU content reaches about 34?ppm, while eTh attains only about 9.8?ppm and potassium is 1.2%. Therefore, the eU/eTh ratio, reaches to a value of 3.4. The same sandstone bed in Abu - Durba Formation possesses eU values reach 67?ppm, whereas eTh values attain 38?ppm and average of potassium is 0.5%. The eU/eTh ratio is about 2, indicates also enrichment of uranium. The eU reaches a concentration of about 40?ppm in limestone of Matulla Formation whereas, the eTh values attains about 3?ppm and average K is 0.1%. Therefore, the eU/eTh ratio reached 13, due to the limestone is phosphatic. High eU value reaching to 80?ppm is recorded in the limestone facies of Sudr Formation, while the eTh values up to 11?ppm and potassium of about 0.9% are recorded. The eU/eTh ratio value reaching 7.3 indicates the high P2O5content. A high uranium content is recorded at the northeastern part of El-Qaa plain area in the Sudr Formation reaching 47?ppm, while low eTh values attaining 7.5?ppm and potassium of 0.1% are recorded.