Similarities and Differences in Weathering and Erosion

Weathering and erosion work together to shape the earth.
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Weathering and erosion are two processes that together produce natural marvels. They are accountable for the formation of caves, valleys, sand dunes and other naturally formed structures. Without weathering, erosion is not possible. Because the two processes work so closely together, they are often confused. However, they are two separate processes. Weathering is the process of breaking down rocks. Whereas, erosion is moving the sediment away from the original location.


Both weathering and erosion are processes that wear away rocks. These two processes collaborate to break down rocks by removing or forcing out particles and sediment. Water is a force that helps both processes to occur.

Chemical Weathering

Chemical weathering occurs when bonds between particles are broken by chemical reactions. When the bonds break, the particles fall apart. These reactions most often occur when water or oxygen react with the elements within the rock. The rock becomes softer upon the reaction. This causes sediment and particles to break away from the rock. When the rock reacts with oxygen it is called oxidation. When the rock reacts with water, it is called hydrolysis.

Mechanical Weathering

If no chemical change takes place, rocks are weathered mechanically. Mechanical weathering can occur through changes in the environment. The most common cause of mechanical weathering is pressure built up by water freezing within the rocks. This type of weathering can also be caused by earthquakes or shifting of the earth’s plates. Temperature changes or salt buildup causing pressure within the rocks can also cause particles of the rocks to break off.

Biological Weathering

Biological weathering occurs when a living organism breaks down soil, rock or other structures. This type of weathering can have characteristics of both mechanical and chemical weathering. Biological weathering may happen when an animal burrows in the ground or when the roots of a plant remove the soil as they grow. This type of weathering is generally a slower process than the other two types. However, respiration from animals, a biological weathering process, can speed up chemical reactions to make chemical weathering occur at a quicker pace.


Once weathering has broken particles away, erosion can occur. Erosion is the process of actually moving the broken sediment, soil or rock particles. Gravity is the major force in erosion, as it causes the particles to fall away from their original location to a new location. However, wind, water and other natural forces can also cause erosion by moving the detached particles.