Levelling and Normalisation of Existing Data Sets

• Parametric, linear or non-linear levelling may be used, where it is possible to reanalyse some samples or recollect samples from some of the same sites, or if reference materials were analysed in both data sets;

• In other situations, it is necessary to apply non-parametric normalisation, using the fractile method or Clarke normalisation.

• Airborne gamma ray spectrometry can be used to overfly adjoining and isolated survey areas to provide an independent Th datum to assist in levelling ground radiometric geochemical data sets.