Piece of Cake
The geologic strata of the “Grand Staircase” is perhaps best described as a 250 million year old layer cake. If so, consider the Vermilion Cliffs looming before you like a 3,000 feet thick red velvet cake, perched upon a Chocolate Cliffs base. This colorful cake can also be read as a stack of differing ancient environments. It took millions of years for each layer to form; time for the earth and landscape to change extensively while sediment stacked and cemented into layers. Geologists further divide the “steps” into specific rock formations: Environmental conditions at sediment deposition—like wetness or dryness—along with mineral presence account for differing rock appearance and color. The Vermilion Cliffs’ namesake reds come from an abundance of iron minerals in the rock sediment. When iron is exposed to oxygen in the air, it oxidizes, or rusts. The same chemistry that applies to a rusty old nail applies to the rock in this rusty-hued plateau.
