The continental crust in Colorado was constructed from several island chains that collided and merged together about 1.75 billion years ago. It was then metamorphosed at depth under heat and pressure, and magma was injected through cracks in the rock. After several million years of erosion the rocks of the Morrison Quarry became exposed at the surface. Layers of sandstone were deposited directly on top of the exposed rocks forming what is known as the "Great Unconformity," a 1.4-billion-year gap missing between one rock layer and the next. These rocks were likely uplifted during the formation of the Ancestral Rockies between 320 and 270 million years ago. The Ancestral Rockies were eventually eroded away, buried by sediments and flooded by shallow oceans. They were brought to the surface once again during the growth of the current Rocky Mountains.

Silicon and oxygen are two of the most common elements on Earth. Together, they make up nearly 75 percent of the Earth's crust, so it is no surprise that they play major roles in forming many of the minerals that we see in rocks. The silicon atom, which has four electrons in its outermost region, likes to form chemical bonds with oxygen atoms, which are attracted to extra electrons. Thus, silicon and oxygen, together with some of the metallic elements, can combine to make hundreds of different minerals. For example, quartz has two oxygen atoms for every silicon atom, and feldspar has two or three silicon atoms grouped with eight oxygen atoms and a few metal atoms. About half of the most common minerals found on Earth belong to the silicate group, as do some beautiful gemstones such as amethyst, opal, and topaz.