Estimation of Relative Crustal Abundance of Radioelements Using Sum-Normalisation and Elemental Ratio Techniques

Airborne gamma-ray spectrometry method was used to estimate relative crustal abundance of radioelements with a view to define target area for possible mineral deposit in some parts of Ilesha schist-belt. This exploration techniques reveal relative concentration of each radioelement using the ratios of elements to sum of elements. Therefore, radioelement concentration contrast between favourable host-rock (granite-gneiss) is a significant pathfinder. eU2/eTh and eU2/K ratios anomaly on radiometric maps may be indicative of mineralisation and/or potential localized radioactive deposits. This method, is environmental friendly and easy to use, it is therefore a good tool to rapidly define target area (s) for mineral exploration at a regional scale. The method may also find application in exploring for other types of deposit characterised by an enrichment or depletion in U, K and/or Th.