During a recent visit to Las Vegas, my wife and I traveled a few miles west to the 196,000-acre Red Rock Canyon. Within the Mojave Desert, this area was once the ocean bottom 500 million years ago. This is before there were the current continents and at a time that the first fish appeared in the seas.
Between 180 and 190 million years ago during the time of the dinosaur, huge sand dunes formed in the southwestern deserts, lithified. Basically, the dunes became rock through this geologic process.
This resulted in Aztec Sandstone cliffs, 3,000 feet high. The red color outcroppings of these cliffs are made of iron oxide. Essentially, weathering has caused the rock containing iron to rust creating hues of red colors.
Anne and I walked down one of the trails leading to the cliffs. Upon closer view, we could see the striations of iron in the sandstone. It is hard to imagine that this was once the ocean floor.