ORIGIN OF SOILS
Ø Soils :- It is a loose material consists of solid particales
· Soil Formation :-There are two type of soil formation
1) Organic Decomposition
2) Weathering of Rock (mostly)
· Organic soil are called as “Cumlose Soil”
· Soil that formed due to weathering of rock or inorganic soil
Ø Voids;- Voids in the soil get filled with water or air or both
Ø Soil Mechanics:-
Mechanics that deal with action of forces on the soil and flow of water in soil.
· Soil mechanics was coined by “KARL TERZAGHI”
Ø GEOLOGICAL CYCLE :-
· Based On Geological Cycle:-
1) Residual Soil:-Soils that are deposited at the place of its origin.
2) Sedimentary/ Transporting :- Soils are deposited away from its origin.
Ø Based on Transported Agents:-
3) Glacier / Ice
1) Water :-
a) Alluvial Soil
b) Lacrustine Soil
c) Marine Soil
a) Alluvial Soil :-The soil that are deposited by means of running water.
b) Lacrustine Soil:- Soil that are formed by means of lake water
c) Marine Soil :- Soil that formed by sea water
2) Air:- Wind Deposit = Aeolian Soil Example:- Sand, Duens,losses
3) Glacier :- Soil is formed by melting of Glacier or ice are called as Glacier. Deposits. Example :-(Taulus )
4) Gravitational Deposit :- This depostion is based on gravity forces.
Based on Forces :-
Ø Different terminology :-
1) Varved Clay :- Alternate thin layers of silt and clay
See in lake (Lacrustanine deposit)
2) Loam :- It is mixture of sand , silt, clay, with each praporation should be less than 50%
3) Moorum :- Mixture of Red gravel and clay. This is used in construction purpose
4) Loess (Aeoline soil):- Uniform silty deposit having high compressibility and low shear strength.
5) Black cotton Soil :- it has high swelling and shrinkage.
It has high compressibity and low strenghth. Highly expansive soil.
6) Bentonite clay :- High swelling and shrinkage , formed by volcanic ash , used as Drilling mud
Ø Organic Soils :-
1) Humus :- Partially decomposed organic matter
2) Peat :- Full decomposed organic matter and fibres in nature
3) Muck :- Fully decomposed organic matter and some fine inorganic matter.
By:- Vaibhav Jadhav