Weathering is a process of breaking down of rocks, in which due to disintegration and decomposition, rocks become weak and start getting separated.
Under weathering, the weakening of rocks takes place in two ways:
1. By mechanical fragmentation.
2. By chemical decomposition.
The process of weakening down of rocks by physical factors like temperature, rainfall, air-pressure, etc. is called disintegration. This type of weathering is called Physical Weathering. The process of weakening down of rocks by chemical processes like oxidation, carbonation, hydration, etc. is called Chemical decomposition. This type of weathering is also called chemical Weathering.
The processes of physical and chemical weathering are different from each other, but both types of weathering are not independent of each other. The effects of factors that participate in physical and chemical weathering cannot be separated from each other. For example, temperature plays an important role in physical weathering, due to which the rocks undergo expansion and contraction and they become weak.
Weathering is completely influenced by chemical composition of rocks. On the basis of chemical composition, the ability to absorb heat in rocks is also affected. Similarly, water will not react with any rock, unless it receives heat by temperature or pressure. The processes of chemical weathering are not the same in all the heating boards. Chemical weathering is more active in tropical climatic regions where the temperature is high throughout the year.
Thus, it is clear that the physical and chemical weathering are not independent of each other and they are controlled by atmospheric conditions.