mechanical and chemical weathering

Mechanical Weathering :

Mechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks, they are essentially torn apart by physical force, rather than by chemical breakdown. Some examples of Mechanical Weathering are salt wedging and frost wedging . Salt wedging occures when water enters the holes and cracks in the surface of rocks carrying salt with it. The water evaporates, and salt is left behind. Later on these salt deposits build up, creating pressure that can cause rocks to split and weaken. Frost wedging occures when the temperature drops then the water freezes. As water freezes, it expands larger than it was in liquid form. The result is that the holes and cracks in rocks are pushed outward.

Chemical Weathering :

Chemical Weathering takes place in almost all types of rocks.Chemical reactions break down the bonds holding the rocks together, causing them to fall apart, forming smaller and smaller pieces. Chemical weathering is much more common in locations where there is a lot of water.

Some examples of Chemical weathnering are Chemical Weathering of granite and of silicates.