Weathering is action of elements of weather and climate over earth materials. There are a number of processes within weathering which act either individually or together to affect the earth materials in order to reduce them to fragmental state. Plant and animal life, atmosphere and water are the major causes of weathering.

Weathering is defined as mechanical disintegration and chemical decomposition of rocks through the actions of various elements of weather and climate.

As very little or no motion of materials takes place in weathering, it is an in-site or on-site process.

This processes are conditioned by many complex geological, climatic, topographic, and vegetative factors. Climate is of particular importance. Not only this processes differ from climate to climate, but also the depth of the weathering mantle. It breaks down and loosens the surface minerals of rock so they can be transported away by agents of erosion such as water, wind and ice. There are two types of weathering: mechanical and chemical.

There are three major groups of this processes: (i) chemical; (ii) physical or mechanical; (iii) biological processes. Very rarely does any one of these processes ever operate completely by itself, but quite often a dominance of one process can be seen.