Different types of Soil
1. Bentonite Clay:
- It is a type of clay with a very high percentage of clay mineral "Montmorillonite".
- This soil is highly plastic has high water absorption properties, has high swelling and shrinkage potential.
- It is formed due to the decomposition of volcanic ash.
- It is used for drilling mud.
2. Black Cotton Soil:
- It is residual soil containing a high percentage of the montmorillonite mineral and has high swelling and shrinkage properties.
- It has a very low bearing capacity.
- The parent rock is Basalt or Trap (igneous rock).
- It is generally dark in colour and cotton grows on this soil easily, hence the name Black cotton soil.
3. Loam Soil:
- It is a mixture of sand, silt and clay and is also known as Garden Soil.
4. Indurated Soil:
- The hardening of clay is due to heat and pressure.
5. Organic Soil:
- The other mode of soil formation is by decomposition of vegetable matter, plants etc. by bacteria etc.
- These lead to the formation of organic soil or clay.
- These soils have characteristics of odour and colour.
- It is also called " Cumulose Soils ". Ex:- Muck, Peat and Humus.
- Muck- Organic matter + Inorganic matter.
- Peat- Fully decomposed organic matter. (Highly Compressible and Fibrous.)
- Humus- Partly decomposed organic matter, also known as Top Soil.
- Organic Soil has poor engineering properties.
6. Gravel:
- Gravel is a type of coarse-grained soil. The particle size ranges from 4.75 mm to 80 mm.
- It is Cohesionless material.
7. Cobbles:
- Cobbles are large size particles in the range of 80 mm to 300 mm.
8. Dune Sands:
- These are wind-transported soils. These are composed of relatively uniform particles of fine to medium sand.
Note:
Lithification: It is the process of conversion of unconsolidated deposits into a hard rocky mass by compaction and cementation.