Evaluation of mineral compositions of surface and subsurface rock samples by neutron activation analysis

The study of the mineral compositions of a definite area is very important to discover interesting elements. In this work, four rock samples were provided from the surface and six rock samples were obtained from different depths of groundwater wells. The area of study belongs to the western side of El-Minia, the Western-Desert of Egypt. The types of collected rock samples are limestone, dolomitic-limestone, and gravelly-sandstone for surface rock samples while the subsurface rock samples are limestone, clay, and gravelly-sandstone. A Neutron Activation Analysis (NAA) is utilised to describe the mineralogical compositions of these samples. The NAA is determining seventeen elements in the surface rock samples including two rare earth elements REEs while it is detected twenty-three elements in the subsurface rock samples including six REEs. The results indicated that the main elements of surface rock samples are (Fe, Na, Al, Ca, K, and Mg) while subsurface samples are (Ca, Fe, Al, Mg, and K) with different concentrations. The data also indicated that the subsurface samples contain (REEs) at reasonable levels than surface samples. The correlation analysis was applied to evaluate the inter-element relationships in the studied area. The obtained results were compared with the corresponding recent studies and it was found that the results agree with previous studies to a large extent.