Utah: A Geologic History
Today, Utah is a land of great diversity and scenery. Many factors have determined the changes the state has undergone through time. In a sense it could be said that Utah has had many different faces.
Through geologic time, Utah has been covered by oceans and inland seas as well as completely dry land. The elevation of the land surface has changed as well, ranging from sea level to over two miles above sea level. There have been periods where the topography has been relatively flat and also periods of mountain building and valley formation.
Utah has not always had the moderate climate that it has today. There have been wet tropical periods, dry dusty desert environments, and cold times that caused glaciers.
The geographic position of Utah has changed through time as well. Although these images represent Utah in its present orientation, the state has not always been so. Due to plate tectonics, the state has move from a position on the equator to its present location. In doing so, Utah has rotated nearly 90 degrees from an east-west orientation to its present north-south position.
These images begin with the Paleozoic which began about 540 million years ago at the expansion of complex life forms. The images give a conceptual idea of what the State of Utah may have looked like in its geologic past. Utah also had a history before that time that covered 3 billion years or more but rocks that age are highly deformed or eroded away so past environments are more difficult to reconstruct.
We don’t know as much about the first 3 billion years as we know about the 540 million years that followed, but rocks older than the Paleozoic are exposed in the Raft River Range, Uinta Mountains, and parts of the Wasatch Range, as well as several other smaller areas of the state. These older rocks give clues to the formation of the continent (including Utah), metamorphism and igneous intrusion, erosion of several miles of sediment, and a variety of environments, including oceans, tidal flats, rivers, streams, lakes, and continental glaciers.