MULTIELEMENT NAA FOR THE CHARACTERIZATION OF SAUDI-ARABIAN ROCKS

[[abstract]]The instrumental neutron activation analysis technique (INAA) was used in the qualitative and quantitative analysis of 48 geological samples from the Umm Al-Birak area in the Kingdom of Saudi Arabia. The samples were properly prepared together with their standards and simultaneously irradiated in a neutron flux of 2.4 ·1012 n·cm–2 s–1 in the reactor facilities of the National Tsing Hua University (THOR) in Taiwan. Gamma-spectra from the high resolution Ge(Li) detector were analyzed using the BRUTAl code. As a result of the analysis of the geological samples, 20 trace elements were identified qualitatively and quantitatively. These elements are: Co, Cr, Eu, Fe, Hf, K, La, Lu, Na, Rb, Sc, Sm, Ta, Tb, Th, U, Yb, Zn and Zr. The concentrations of these elements have been used in the investigations of the geochemistry of the Umm Al-Birak microgranite site using the BMDP computer code of the Ministry of Petroleum and Mineral Resources. This investigation showed that the high grade area is a differentiated rock that crystallized in a late stage of the Umm Al-Birak microgranite area.[[fileno]]2060122010013[[department]]工程與系統科學