I'm putting together an exercise for an undergraduate class the purpose of which is to introduce students to the Piper diagram for interpreting geochemical processes in groundwater. What I'd like is to see is either salinisation overtime or variations in salinisation over a wide area onto which they could then draw a salinisation line on a map. Ideally, it would be good if the data showed a change in geochemical facies visible in the Piper diagram as this would help introduce them to the value of the concept.
If anyone has or can recommend a data set of this nature I'd be very grateful. Thanks.