Sea Stack
The actions of wind, water, and time wear away the softer rock material around the harder Sea Stack.
This action of erosion eventually separates the Sea Stack from the surrounding land. In time, the Sea Stack will be eroded.
Hoodoo
The actions of wind and water freezing/expanding over time results in Hoodoo formations. The top of Hoodoos are typically harder rock than that below. This harder "head" of the formation reduces erosion through the action of rain. Water does seep into cracks and when it freezes, expands to force rock material apart. Areas with numerous freezing and thawing cycles have a higher percentage of Hoodoo formations.
Arch
Wind and water erosion remove the softer rock material away from harder rock material found around and above. This material is carried away to reveal an arch formation.
Mushroom Rock
The action of wind and sand over time produces Mushroom rocks. Due to the hardness of the rock and the height that windblown sand can reach, the rock receives non-uniform erosion (the bottom gets eroded more than the top).
Canyon
The action of water in the form of rivers and streams cut into and carries away rock materials. Over thousands of years, this action produces deep, steep sided carvings in level plains.