Thematic Map

http://soils.usda.gov/use/thematic/moist_regimes.html

This is a representation of a Thematic Map because it shows a specific them (in this case soil regimes), in relation to specific geographic areas (in this case the contiguous United States). It is not designed to show multiple geographic features such as forests and roads. It specifically portrays spatial variations that are related to geographical distributions such as states.