Geologists working in mountainous terrain were the first to map
and interpret in three dimensions and as a result, made the first
contributions to our understanding of mountain building and
structural geology. However, geology during the 1900s has been
dominantly a two-dimensional exercise in data gathering and
interpretation. The standard output of geological surveys and
university research has been the geological map and the standard
methodology of the mineral explorer has been surface mapping
and prospecting. The future will be concerned far more with the
third dimension.