Weathering and its types

Published on 31 Jan 2025

Weathering is the mechanical disintegration and chemical decomposition of rocks through the actions of various elements of weather and climate. There are three major group of weathering processes. 

Chemical weathering 

Process through which the rock interacts with chemicals to change its composition. Includes processes like,

• Solution:  Involves removal of solids in the solution and depends upon the solubility of mineral. 

• Example: Dissolution of calcium carbonate and calcium magnesium bicarbonate in limestone 

• Carbonation: Reaction of carbonate and bicarbonate with minerals.

• Example: Dissolution of calcium carbonates in carbonic acid resulting in cave formation 

• Hydration: It is the chemical addition of water.

• Example: Calcium sulphate with water forming Gypsum 

• Oxidation and reduction: Based on the addition and removal of oxygen molecules. 

• Example: Minerals of Iron, Manganese and sulphur 

Physical / mechanical weathering 

Depends upon - Gravitational force, Expansion force due to temperature changes, Water pressure etc. It can be of following types.

• Unloading and expansion: Continued erosion causing vertical pressure release leading to expansion of upper layers of rock resulting in disintegration and results in formation of exfoliation domes.  

• Temperature changes and expansion: High temperature leading to expansion of surface layer rocks and formation of stress. This leads to fracturing of rocks parallel to the surface and formation of tors. 

• Freezing thawing and frost wedging: Effective in regions of repeated freezing and melting.

• Salt weathering: Due to expansion of salts in rocks due to thermal action, hydration and crystallisation. 

Biological weathering 

• Due to burrowing and wedging of organisms like earthworms, rodents, etc. It is also influenced by human activity such as ploughing and cultivation apart from natural biological process like decaying.

Tags:
Geography

Keywords:
Weathering and its types weathering types of weathering Chemical weathering solution carbonation hydration oxidation reduction Physical weathering mechanical weathering Biological weathering

Syllabus:
General Studies Paper 1

Topics:
Physical Geography