Imagine being able to cut out a block of the Earth so that you can see what features lie beneath the surface. We will refer to the surface as the map view and the sides as the cross sections.

With a cross section view we can begin to apply our geological principles -- superposition, original horizontality, cross-cutting relationships, ... -- and begin to work out the sequence of events that produced the materials beneath the surface. Look at the cross section given above and, when you are ready, take a short quiz to see how well you can decipher Earth history.