A cool-looking rock. A result of weathering.
Weathering is the process of rocks breaking down into smaller pieces. Sometimes, weathering can create amazing rock structures. There are two types of weathering. Chemical weathering and Mechanical weathering. Read more about them below.
Chemical Weathering occurs when chemicals break down what holds rocks together, causing them to fall apart and break into smaller pieces. Chemical Weathering is common around places near water. This is because water is important to many of the chemical reactions that can take place. Sand is sometimes the result of chemical weathering.
Mechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks. The rocks are essentially torn apart by physical force, rather than by chemical breakdown. The most common type of mechanical weathering is the constant Ice Wedging. The water comes into the small cracks and holes in the rock and if the temperature is below 0°C, the water freezes and expands making the crack bigger. The rock then goes through the process again and the water comes into the cracks again and like before, freeze and expand the crack. It continues until the rock has been completely broken down.
Examples of Mechanical Weathering
There are three different kinds of mechanical weathering.
- Frost Wedging - Alternating freezing and thawing of water as shown above.
- Unloading - Large masses of igneous rock are exposed by erosion and entire slabs begin to break loose.
- Biological Activity - Activity of organisms, plant roots, burrowing animals, and humans.