Geologic cycle: The most important of these begins with molten magma from within the earth crystallizing into rock then continues with the rock being broken down into soil and that soil then being converted back into rock, This process repeats itself over and over again through geologic time.
Types of weathering:
i) Mechanical weathering
ii) Chemical weathering
iii) Spheroidal weathering
iv) Biological weathering
Mechanical weathering: It is also termed as physical weathering in this process the rock surface is broken into smaller pieces without any chemical change. The smaller broken rock pieces are
deposited at and over the present rock on the flat surface and these are accumulated at the end of slopping surface. It is slow process with water and temprature
Chemical weathering: In this process the rock surface is broken into small pieces by chemical decay of minerals. It is chemical reaction between the atmospheric gases and surface of rockweathering are oxidation, hydration, carbonation and solution.
Spheroidal weathering: If joints and fractures in rock beneath the surface form a 3-dimentional network the rock will be broken into cube like pieces separated by fracture water can penetrate more easily along these fracture and each of the cube like begin to weather inward
Biological weathering :Plants and animals play an important role in the break down and decay of rock indeed their part in soil formation is of major significance