Displayed below is an example of how Geographical Information Systems can be used to extract useful information from data.

The example is a fictitious set of soil samples taken over a rectangular grid. They can be plotted on a map with their gold content quite easily, but seeing any trend in high or low values is difficult.

One method of graphically displaying the magnitude of the gold values would be to create a thematic map such as the one below:

This map gives a good visual indication of the relationship between high and low gold values across the map. Another useful method to display trends in the data is to produce a coloured continuous shade thematic map as shown in the figure on the next page.