Analytical methodology for geochemical features and radioactive elements for intrusive rocks in El Sela area, Eastern Desert, Egypt

On the basis of Clarke analyses, geochemical series of chemical elements of the intrusive rocks of El Sela are identified: two-mica granite: Ni36- Mo7.8- U2.7- Co2.4- Cu1.8- Th1.3; microgranite: U55- Ni20- Co7.3- Mo5.4- Zn3.6- W3.1- Cu2.4; dolerite: U37- Mo18- Cs11- Nb9.1- Sn7.3- W4.3- Th3.9- Y3.6- Zr2.9- Ni2.3- Rb2.2- Hf1.6- Zn1.6- Ba1.2; and bostonite: Ni54- Mo14- Rb9.8- Ta5.3- Nb4.4- Cu3.3- Y2.4- U2.3- Hf1.7- Zr1.4- Th1.3. Microgranite and dolerite have the highest U-contents whereas the two-mica granite has high Th. Microgranite and two-mica granite and bostonite belong to calc-alkaline affinity, while dolerite belongs to tholeiitic. Two-mica granite, microgranite and dolerite fall into meta- and/or peraluminous rocks, whereas bostonite fall in the peralkaline field. Two-mica granite and microgranite are located volcanic arc syn-collision granites, while dolerite and bostonite fall into within plate field. The temperature of crystallisation of two-mica granite ranges from 700°C to 750°C, microgranite from 750°C to 800°C, dolerite from 800°C to 900°C and bostonite ranges from 950°C to 1020°C. The contents of uranium, thorium and potassium were determined and showed high concentrations for radioactive elements.