Spot (4) Has evidence that there were waves here at some point. It looks as if the sand/surface debris was moved back and forth, creating this pattern in the sand. Spots (5) and (7) show evidence of water erosion. The smooth edges of both hills mean that water once flowed through that area, carrying little pebbles and rocks that gradually shaped and smoothed those mounds. An example for this would be how there are smooth areas in the Grand Canyon where scientists have concluded that some, if not all, of the Grand Canyon was formed by flowing water. "Rapid uplift, cracking, and surface drainage of receding floodwaters provide both the path and the necessary volume of water to quickly carve out Grand Canyon," says scholars on icr.org.
