The rocks around our new home have these strange structures of lines tilted at different angles. What caused that?
Answer:
This is a layer of rock known as the Navajo Sandstone. The angles lines are called cross-bedding, and they were formed by sand dunes. As the wind blows sand up the dune, it slides down the opposite side, making repeated layers. You can see exactly the same patterns in the dunes of modern deserts. The Navajo Sandstone extends over 100,000 square miles, telling us that during Jurassic times, this area looked much like the modern Sahara Desert.
