Difference between Mechanical Weathering and Chemical Weathering

Difference between Mechanical Weathering and Chemical Weathering

When rocks are reduced by environmental changes like rainwater, significant temperature fluctuations, and other reasons, this process is called weathering. Weathering can occur for many reasons. There are two main reasons for weathering: Chemical Weathering and Mechanical Weathering. These two are very different, but the difference is not hard to see.

Mechanical Weathering Vs. Chemical Weathering

Mechanical Weathering does not alter the rock’s chemical makeup. Chemical Weathering does. Chemical Weathering, on the other hand, alters the rock’s chemical composition. Chemical Weathering and Mechanical Weathering are both caused by different agents.

Mechanical weathering refers to the process by which cracking rocks takes place without altering their chemical composition. Freeze-thawing weathering is the most common form of mechanical weathering.

The coasts are most affected by water if rocks are porous. Water can seep into rocks and freeze inside due to their porosity. The rock expands and cracks when the ice forms.

Chemical weathering is a process that cracks up rocks because of their chemical composition. This happens when rainwater gets to the rock. It either decomposes the rock or is eaten away.

This is known as carbonation. This happens when some acidic or carbonic water or water from the ocean touches sedimentary rock, such as limestone or chalk. It causes it to evaporate.

The acidic water and calcium carbonate undergo a chemical reaction, which transforms it into calcium bicarbonate. It becomes soluble, and then it can be removed from the solution. This kind of weathering occurs in hot, humid conditions.

What is Mechanical Weathering?

Also known as disaggregation and physical weathering, mechanical weathering causes the rock to break down into smaller pieces. Water, whether it is in liquid or solid form, is the main reason that mechanical weathering takes place in rocks.

Further explanation: Liquid water can seep into cracks in rocks and make its way inside. If the temperature drops, water can freeze in rocks, which causes the rock to expand and crack.

The ice acts as a catalyst. It slowly stretches the cracks in the rocks and divides them. Liquid water is used to complete the weathering process by moving out any small stones that have been lost in the fissure. This process is called cold weathering.

Mechanical weathering can also be caused by temperature changes. This is known as thermal stress. Heat variations cause the rock to expand with heat and contract with cold. After a time, the formation of rock begins to crumble. The rocks begin to fall into smaller pieces after a certain time.

What is Chemical Weathering?

This term defines a process of breaking down rocks through chemical reactions that occur around minerals in the stones and the environment. The main agent of chemical weathering is water.

Water contains many synthetic compounds. Water contains many weak acids like carbonic acid, which can leak into rocks and start the process of rock breaking down.

This acid is produced by mixing rainwater with carbon dioxide gas. There are other types of acid in the rain like nitrogen gases and sulfur dioxide, which act as chemical weathering catalysts.

Coal-burning power plants are only one source of sulfur dioxide. Others come from volcanoes or coastal marshes. All these sulfurous gasses eventually come into contact with rainwater and oxygen, which generates sulfuric acid.

The acid is strong and can cause a lot of damage to plants and rocks. The unusual chemical weathering process of oxidation occurs when oxygen reacts with another substance to create compounds called oxides.

Difference between chemical weathering and mechanical weathering

  • While Mechanical Weathering doesn’t alter the chemical compositions of rocks and stones, Chemical Weathering can.
  • Mechanical Weathering is done in dry and hot climates. Chemical Weathering, on the other hand, is done in hot and humid climates.
  • Water, temperature, and moisture are the main agents for mechanical weathering. Chemical weathering is characterized by oxidation, solution, and carbonation.
  • The rock is affected to great depths by mechanical weathering. Chemical weathering, on the other hand, has only a superficial effect.
  • The rocks will be broken down into smaller pieces by Mechanical Weathering, while Chemical Weathering forms new minerals on top of the existing rock.


Both chemical weathering and mechanical weathering are amazing ways the Earth decompresses or erodes its surface. Mother Nature amazes us with her ability to dissolve and break down rocks and create new minerals. The weathering process is then followed by erosion, which removes these minerals and rocks from another place, affecting everyone. If the primary agents are considered, you can easily see the differences between erosions and weathering.