Definition of clay:
It is one of the most important type of soil. These are finely grained particles of size less than 0.002 mm. These are cohesion plastic soils and are named as clay.
It is the most easily available type of soil. Many local varieties of this type are available some of which are as follow:
- Boulder clay:
There is a wide range of particle size of the calcareous clays which ranges from boulders (< 300 mm) to a very fine rock flour ( < 0.002 mm)
- Varved clay:
In this type, the alternating thin partings of very finely grained sand or silts are present.
Montmorillonite a mineral formed due to the chemical weathering of the volcanic ash is the principal constituent of this type . It is usually found near the mountains where volcanic processes occur.