The process of soil formation include:
(1) PHYSICAL PROCESS: (i) The grinding of rock surfaces by solid materials carried by wind. water and moving ice results in the breaking of the rocks. (ii) The freezing and melting of ice within the rock results in the breakage of rocks (iii) The continuous expansion and contraction of rocks due to variations in the intensity of temperature results in the breaking down of rocks. (iv) The action of running water also eats up the rocks. resulting in breaking down of rocks;
(2) BIOLOGICAL PROCESS: (I) The actions of some animals like earthworm and termite cause rock to break. (ii) The burrowing activities of earthworm and termite into rocks cause their breakage. (iii) Roots of plants which penetrate rocks also help to break down the rocks. (iv) Human activities during tillage, use of plough and harrow also indirectly break down rocks.
(3) CHEMICAL PROCESS (i) Solution: Water dissolves soluble minerals or rocks in the soil. (ii) Oxidation: The reaction of oxygen with rocks results in breakage of rocks. Carbonation: Carbon dioxide which dissolves in water to form a weak carbonic acid reacts with rock to break it down. (iv) Hydration : The attachment of water to rocks results in their breakage.