Erosion is the wearing away of sediments and rock by some outside force. There are two main tips of erosion, water erosion and wind erosion. This book is about wind erosion. Wind erosion is caused by particles, often sand, being picked-up by wind and flung against solid objects. This acts as a sand paper that wears down the rock making strange shapes and beautiful forms in the stone.
The three types of sand movement causing erosion are suspension, saltation, and creep. Suspension is when small grains of sand are swept up into the atmosphere and held ‘indefinitely.’ Saltation is when medium sized grains of sand skips along the ground or rock making small scooped line in the stone. These lines can tell you the direction in which the wind is moving. The last movement of sand affects the larger grains that cannot be lifted off the ground. It is called creeping when the medium size grains skip off the big ones and slowly move them. This accounts for 25% of desert movement.
Navajo sandstone is in the Glen Canyon Group. The Glen Canyon Group is a group of sandstone types spread across NV, UT, northern AZ, NM, and CA. Navajo sandstone is formed when water seeps through sand dunes and bonds the sand together making sand stone. Once the dune solidifies the wind blows the grains from far and near against the surface carving it away. Much of the Navajo sandstone was formed in the Jurassic period and carved over thousands of years.