Isotopic dating of El-atshan uranium mineralization, eastern desert

The galena associated with uranium mineralization in El-Atshan mine was dated by the Pb/Pb isotopic method. Three model ages were calculated. The Russell-Stanton-Farquhar model gave a geologically accepted age of 222 m.y. which is concordant also with the age of the K-feldspar porphyry dyke (215 m.y.) of Wadi Kereim and close to the age of Nasb El-Qash trachyte (245 m.y.) as obtained by Rb/Sr age dating method. The Holmes-Houtermans and Russell-Farquhar-Cumming models gave B-type anomalous ages of 656 m.y. and 348 m.y., respectively, which may be interpreted as due to contamination with older Precambrian galena provided the validity of the models