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What is biological weathering ?

Answer Text:
Biological Weathering
-Weathering of rocks due to action of living organisms on them.
- Takes place in form of mechanical or chemical weathering through the action of:
a) Plants.
b) Animals.
c) Human activities.
Mechanical weathering caused by living organisms
- The roots grow bigger into the cracks and joints of rocks widening them.
-With time the rock separate into blocks (wedging mechanism).
-The widened joints and cracks also provide passages for moisture and air to penetrate deeper into cracks facilitating hydrolysis and
solution to act at deeper levels.
-Burrowing animals dig and break up small bits of rock from the main rock mass and bring them to the surface.
-By digging they also provide passages for other elements like gases and moisture to reach rocks that are deep.
-Large herds of animals such as cattle, zebra etc. pound the rocks with their hooves
as they move resulting in resulting in mechanical breakdown of rocks.
-People break up rocks by using explosives in mining by exploding bombs on the ground and during building of houses and construction of roads.