On the left is a geological map of Utah. Each color represents different rock that is exposed at the surface, or near the surface, just covered by soil. Without an explanation the colors mean very little so there is a key in the upper right. Here, different colors represent rocks of different ages. Yes, there is standard color scheme! Yellows are most recent rocks, or sediments recently deposited by rivers. Greens and aqua are Mesozoic rocks (time of the dinosaurs). Blue, gray-blue to brown colors are the older rocks (Paleozoic). Igneous rocks of what ever age get their own bright colors: reds, pinks, magenta. They really liven up a geologic map!
The lower right contains a cross section, as if you cut through the ground, took half away, and saw what was inside. Older rocks are on the bottom, younger on the top, as you might expect.The geology under Utah leads to amazing landscapes. Utah is the home of Bryce and Zion, also Arches National Park and many others. In the north are beautiful mountains and wonderful ski areas.