Detail of the Sandstone – While driving on the East Entrance Road in Zion National Park I was struck by the visibility of the various layers of sandstone. Over millennium deposits of sand of varying sources and makeup were distributed via wind and water. The resulting sandstone shows these deposits as layers of varying colors. I found the details to be nearly as vivid as the growth rings of a tree where one can determine the good growth years from the bad just by ring thickness. In the case of this sandstone, geologists can and have learned a lot about how these rocks were formed from the sediment deposited over time.