Geochemical mapping: technique or art?

Various techniques for producing geochemical maps are reviewed. Interpretation of processes leading to the observed element distribution will be facilitated when the data structure is displayed in a geochemical map. This can be achieved by using the boxplot or percentiles, evenly spread over the whole data range, for class selection. Map scale (to purpose), type and amount of background map information, choice of symbols (black-and-white mapping) and, for colour maps, the colour scale are important issues that need consideration.